0 degrees outside and the Z lean seized!!!

[2XTREME]

I screwed up bad today.A buddy of mine was bagging to ride the Z and so I gave in and let him take it out.I just had a gut feeling that it was too cold and maybe the Z wasn't jetted right.The crappy thing is I checked the plug 4 or 5 times today and it was a nice almond-chocolate color.Exhaust smelled and looked good.Why do you guys think this happend and why did the plug lie?I haven't torn it down yet.I was able to break the piston loose.I hope it didn't score the cylinder wall bad.It would be nice to replace rings hone the cylinder and put her back together.What's the chance!Anyway I am pretty sad,I had her running a whole two days.
X:cry: :mad: :wondering

[Semo Tri Z]

Are you running the stock air box setup?? My Z always leaned out on top end with the stock air box system. I put on a pod filter and haven't had a problem since.

[69HemiGTX]

Sorry to hear that 2X! :( From what you described, I would say that you had a cold seizure. What happened was the piston got hot quickly, before the cylinder was up to temp, and it swelled in the bore. Aluminum (piston) transfers heat much faster than iron (bore), so that's more than likely what happened. Since the ambient air temperature was low, then your cylinder was near the same temp when you started it. Being able to break it free afterwards is a good indicator that it didn't do too much damage. But don't quote me on that! :lol:

[OldSchoolin86]

I screwed up bad today.A buddy of mine was bagging to ride the Z and so I gave in and let him take it out.I just had a gut feeling that it was too cold and maybe the Z wasn't jetted right.The crappy thing is I checked the plug 4 or 5 times today and it was a nice almond-chocolate color.Exhaust smelled and looked good.Why do you guys think this happend and why did the plug lie?I haven't torn it down yet.I was able to break the piston loose.I hope it didn't score the cylinder wall bad.It would be nice to replace rings hone the cylinder and put her back together.What's the chance!Anyway I am pretty sad,I had her running a whole two days.
X:cry: :mad: :wondering
What was your procedure for checking the plug?

[twgranger]

That sucks. What jetting are you running?

[Meat-BoX]

I just stay inside when its that cold. I busted the Tecate out last year in the snow and I thought it was gonna blow for sure. Were you rippin in the snow? Them 2 strokes are just to crazy to be riding in junk like that. Its like sitting on a ice patch and going balls out. Not good. Next time get your friends wallet before you let him ride.:naughty:

[Blown 331]

That does suck and I know how you feel.

[shudup]

Sorry to hear that 2X! :( From what you described, I would say that you had a cold seizure. What happened was the piston got hot quickly, before the cylinder was up to temp, and it swelled in the bore. Aluminum (piston) transfers heat much faster than iron (bore), so that's more than likely what happened. Since the ambient air temperature was low, then your cylinder was near the same temp when you started it. Being able to break it free afterwards is a good indicator that it didn't do too much damage. But don't quote me on that! :lol:

i agree problyey cold seize
on a liquid cooled motor, if its real cold you sould let it warm up to or close to full temp befor riding it

[TeamGeek6]

I checked the plug 4 or 5 times today and it was a nice almond-chocolate color.Exhaust smelled and looked good.Why do you guys think this happend and why did the plug lie?

It didnt lie.

The plug wont necessarily read out oil mixture, especially if its burning efficiently. Thats partly because of the fuel : oil ratio. Realize that:

A/F = 15.5:1 (14.7 is ideal)
F/O = 40:1 (I dont know what youre running, but 40 is common)

That leaves:

A/O = 620:1

Im assuming its around those figures, 16:1 is about the limit of lean flammability and if it was that lean, it wouldnt run well.

The plug wont read 620:1, theres no oil left to color the plug.

Theres 2 kinds of "lean," lean on fuel and lean on oil. I run very lean on fuel and heavy on oil.

I could start my R in the summer and hear the piston rattle from lack of premix, so I increased it from about 40:1 to 30:1 and the rattle went away. Mine is set up similar, and I wont go out and start it for any price. $50.00 cash couldnt get me to even kick start it today at 20* F.

Its OK to run cold as long as the oil is right, and has had time for the cylinder to heat to make the oil flow. Pour some premix oil out and see how thick it is in the winter. If its not warm, the piston will scrape it off the cylider walls, and BOOM.:eek:

I block the radiator to keep engine heat up. My avitar picture is ripping wide open at - 10*F and didnt hurt it a bit, but it was running very rich back then.

[2XTREME]

Semo,
No,I am running the K&N right off the carb with a prefilter.

69Hemi,
I think you may be right.Hopefuly it isn't that bad.

Oldschoolin,
I open the throttle wide open in a straight away,Pull the clutch in and hit the kill switch.Coast her to a stop and push her in the shop.

Meat,
Yeh I know what you mean about the friends wallet.I thought all of us riders had the same morals.If you break somebody's toy,you fix it.He never offered.So I just loaded her up and took her home.We running her pretty hard on gravel,snow and dirt.

X:wondering :cry: :mad:

[2XTREME]

It didnt lie.

The plug wont necessarily read out oil mixture, especially if its burning efficiently. Thats partly because of the fuel : oil ratio. Realize that:

A/F = 15.5:1 (14.7 is ideal)
F/O = 40:1 (I dont know what youre running, but 40 is common)

That leaves:

A/O = 620:1

Im assuming its around those figures, 16:1 is about the limit of lean flammability and if it was that lean, it wouldnt run well.

The plug wont read 620:1, theres no oil left to color the plug.

Theres 2 kinds of "lean," lean on fuel and lean on oil. I run very lean on fuel and heavy on oil.

I could start my R in the summer and hear the piston rattle from lack of premix, so I increased it from about 40:1 to 30:1 and the rattle went away. Mine is set up similar, and I wont go out and start it for any price. $50.00 cash couldnt get me to even kick start it today at 20* F.

Its OK to run cold as long as the oil is right, and has had time for the cylinder to heat to make the oil flow. Pour some premix oil out and see how thick it is in the winter. If its not warm, the piston will scrape it off the cylider walls, and BOOM.:eek:

I block the radiator to keep engine heat up. My avitar picture is ripping wide open at - 10*F and didnt hurt it a bit, but it was running very rich back then.

I am definalty gonna richen it up now.Do you think I need to play with jetting or just richen my fuel.I use synthetic and mix 50:1. I have been doing this for more than 10 years and have never cold seized one.Then again I have never been out in 0 degree weather with any of my 2-strokes.
X

[hotroddal]

ive had all my 250r's out in -10 weather, ive never had a single problem and I was really riding em hard too, power sliding for 30 seconds at full throttle, whippin donuts like mad just rompin on her, -10 being the coldest but mainly the temp is around 12 degrees when i ride and all i mainly ride in the winter is my 250r's, thats pritty weird that nuthin happened to mine and your engine seized and mine didnt.

[Lomax]

Man that really sucks, I hate to hear about it. Maybe the damage isnt too rough

[BigGreenMachine]

Cold seizure. Did it to the Tecate on two seperate ocassions with two different jetting setups.

Good news is a hone usually will take care of it considering it isnt deep scoring. Under all circumstances with the Wiseco piston and rings you should let the bike get up to operationg temp. I do and haven't had an issue since. Make sure to check your ring gap and then retorque the head bolts after the first warm up run.

Hope its a quick fix.

[Billy Golightly]

In my opinon a cold seizure is a cold seizure, and jetting dont have much to do with running the engine wide open and making the piston expand twice as fast as the cast iron cylinder sleeve.

[BigGreenMachine]

In my opinon a cold seizure is a cold seizure, and jetting dont have much to do with running the engine wide open and making the piston expand twice as fast as the cast iron cylinder sleeve.

+1
Thank you Billy, I had that in my mind to say but it was forgotten during the rant. lol

[Trikeaholic]

ive had all my 250r's out in -10 weather, ive never had a single problem and I was really riding em hard too, power sliding for 30 seconds at full throttle, whippin donuts like mad just rompin on her, -10 being the coldest but mainly the temp is around 12 degrees when i ride and all i mainly ride in the winter is my 250r's, thats pritty weird that nuthin happened to mine and your engine seized and mine didnt.


same here, winter, summer, same set up on my pingers, only they are faster in winter! (nice dense cold air!)

[TimSr]

Its a little hard to diagnose over a message board, but unless you started it up and immediately ran the crap out of it while it was still cold, Id have my doubts about a cold seizure. Mine has suffered through many Ohio winters. In my long term relationship with my Z, if it was running good, and you had been riding it a while, and plug looked fine, and then it later seized, the first thing Id look at is an impeller failure. When coolant stops flowing, top end gets really hot, which makes it run really really lean. Impeller failures are common, and Ive rebuilt more than one top end beacuse of it.

[Jason Hall]

I'm with billy on the cold seizure also. I don't think a Tri-z has an exhaust bridge, that gives the ring a big chance of catching the edge of the exhaust port. I would not be able to function until I pulled the pipe off & looked in the exhaust port. I would never even ride my R's in the winter without bumping my jets. I move the needle sometimes also, just to keep my throttle respose sweet. It's kinda a fact of life that you need more fuel when the temp drops. Some of you guys must have your 2-strokes jetted fat in the summer. I'm not trying to start an arguement here, I just run my stuff on the lean side & to keep from trashing my motor I bump the jets up in the winter.

[2XTREME]

Its a little hard to diagnose over a message board, but unless you started it up and immediately ran the crap out of it while it was still cold, Id have my doubts about a cold seizure. Mine has suffered through many Ohio winters. In my long term relationship with my Z, if it was running good, and you had been riding it a while, and plug looked fine, and then it later seized, the first thing Id look at is an impeller failure. When coolant stops flowing, top end gets really hot, which makes it run really really lean. Impeller failures are common, and Ive rebuilt more than one top end beacuse of it.
That would make more sense to me.The only reason I say this is because I let it warm up for awhile and then took it out and ran a few laps at low throttle.She was plenty warm by the time my friend got on it.It was also blowing some coolant out the over flow.I am still a little confused.The guys on here that said they don't re-jet in the winter.Man you guys are insane.I always re-jet in the winter.The reason for them running better in the cold is because they are lean.Then again we live at an altitude of 8000 feet.This Z was jetted for cold,but then I put the boost bottle on and changed the pipe.I should have went one step fatter on the main jet.I should know the verdict this weekend.I plan on tearing the yop end off.Thanks for all of the ideas guys,
X:beer

[Mosh]

I screwed up bad today.A buddy of mine was bagging to ride the Z and so I gave in and let him take it out.I just had a gut feeling that it was too cold and maybe the Z wasn't jetted right.The crappy thing is I checked the plug 4 or 5 times today and it was a nice almond-chocolate color.Exhaust smelled and looked good.Why do you guys think this happend and why did the plug lie?I haven't torn it down yet.I was able to break the piston loose.I hope it didn't score the cylinder wall bad.It would be nice to replace rings hone the cylinder and put her back together.What's the chance!Anyway I am pretty sad,I had her running a whole two days.
X:cry: :mad: :wondering
first of all, treat your bike like your wife.NEVER let anyone ride them;) as far as why the bike siezed? did any one check the ring end gap before installing the piston? if that is not right,it will seize if too tight ,or shatter a psiton if too loose. in any respect, i am sorry to hear that. and make sure you get the crankcase cleaned out REAL GOOD, before you redo the top end again. and also, if you only had the bike runnin 2 days, you should not have been runnin wide open plug chops.:crazy: the motor needs at least 6-8 hours mild break in time before you do that!

[TeamGeek6]

I am definalty gonna richen it up now.Do you think I need to play with jetting or just richen my fuel.I use synthetic and mix 50:1. I have been doing this for more than 10 years and have never cold seized one.Then again I have never been out in 0 degree weather with any of my 2-strokes.
X

If its really cold seize... it bothers me that it was losing coolant, thats overheating.

Sure a hot piston expands faster than a cold cylinder sleeve, but yall, realise that cant work that way. The CTE for both steel and aluminum are around 0.000006" per degree Farenheit and if the cylidner is cold and hasnt expanded inward, that leaves more clearance for the piston to expand. 757 degrees F would suck up 0.005" piston to cylinder clearance, but theres no way the piston will heat that much and not transfer heat to the cylinder, especially when there is more surface area in the cylinder to take heat than on the piston crown. Secondly, a cold cylinder means more clearance, not less, so its less likely to seize with hot piston and cold jug than if both are hot.

but its a good sounding story to those less experienced....


Since this happened, Id be tempted to see how much the premix oil can be increased before fouling a spark plug and then maybe reduce premix a little. Itll slobber like a drunk at 20:1, might try 30 or 35:1 and then monkey with the fuel. Since the plug is reading about right on as far as fuel, increase premix till it reads darker on the plug from oil.

Thing is, cant let the premix foul the plug or the fuel will look rich when it really isnt.

That extra oil might not help if the cylinder is too cold. Id either block the radiator off if it has one, or wrap the cylinder with insulation and make sure its warm. Might even have to wrap the header of the expansion chamber to keep the exhaust warm. Id want to see at least 150*F on the outside of the cylinder, my R runs 180 normally, which is about the same as the radiator water.

Sorry I cant give you anthing more specific, I dont know the engine that well.

Time to rebuild the top end and make sure its all up to snuff.:cry:

[2XTREME]

first of all, treat your bike like your wife.NEVER let anyone ride them;) as far as why the bike siezed? did any one check the ring end gap before installing the piston? if that is not right,it will seize if too tight ,or shatter a psiton if too loose. in any respect, i am sorry to hear that. and make sure you get the crankcase cleaned out REAL GOOD, before you redo the top end again. and also, if you only had the bike runnin 2 days, you should not have been runnin wide open plug chops.:crazy: the motor needs at least 6-8 hours mild break in time before you do that!
This motor is not fresh.I meant after the banshee rear end mod and all of the other mods I have been doing in the last month.LOL I know better than doing that to a fresh top end.LOL:lol:
X

[Mosh]

This motor is not fresh.I meant after the banshee rear end mod and all of the other mods I have been doing in the last month.LOL I know better than doing that to a fresh top end.LOL:lol:
X
oh i see. the motor was broke in.:lol: my bad. i did not know that. then i would have to agrre with tim sr. the waterpump might be the problem.

[2XTREME]

After it cooled down,I just put it in gear and gave her a couple rocks forward and back and she broke loose.I hope that is a good sign.I refuse to fire it up untill I look at the cylinder wall.I squirted some straight 2-stroke oil down the spark plug hole and turned it over a few times with the tether Kill switch off.She turns over,but it feels like there is a little drag on the piston.I am not sure if this is aluminum attached to the wall or if it is a bearing half trashed on the rod or WHAT!!
X:wondering

[Tri-ZNate]

Sounds like what happened to our quadsport. No oil (didnt realize at the time a bolt fell out. Dont ask) so the piston froze in its tracks. We kicked it over and it felt fine so we pull started it again went about 100 feet and that was when the aluminum piston decided to weld itself to the cyclinder wall :(. It may feel good now But I'll bet your in for a surpise.

[TimSr]

Spitting coolant, and then it breaks loose after it cools down? Now Ill start taking bets on an impeller!

All the theory expressed in this post, I agree with. Cold AIR is denser and makes a motor run leaner (once it reaches operating temperature). A cold motor runs a lot richer. This is why we see so many problems of fouling plugs at startup and running lean at operating temp in winter. Also, if you run without a thermostat in your TriZ in zero degrees, your bike will run rich all day, and its not because of the jetting.

Ive had my Z long enough to diagnose most major engine problems in couple of minutes, and Im just saying that if mine were to seize, before diving into carburation theories, the first thing I would do is make sure the plastic end is still on the impeller, and from the information in the posts youve added, Ill bet its not. If you can do compression test, it will save you the trouble of tearing it down. Sometimes this happens once, and they are okay afterwards. More often, it leaves piston rubbings on the cylinder walls which will result on lower compression. I had them seize in races. Let it cool, drove it back to the pits, changed the impeller, and ran the second moto.

It sounds like you were diligent in monitoring your plug just for fear of this problem, and I believe a lean condition would have given you some warning.

[2XTREME]

TimSr,
Thanks for the input.I will pull the Water Pump cover off and inspect it first before pulling the top end off.I will definatly at least pull the pipe and try to look at the piston skirt.
Thanks Again,
X:naughty:

[mywifeknowseverything]

Sorry to hear that man!!!!!

I hope yours doesnt look like mine when she Siezed in June...1 Tank at 30:1 on Fresh Piston and Head:mad: Crank Bearings went:mad:

http://images.snapfish.com/3457286323232%7Ffp335%3Enu%3D3239%3E%3A%3B3%3E873% 3EWSNRCG%3D323337%3A97557%3Cnu0mrj

http://images.snapfish.com/3457286323232%7Ffp337%3Enu%3D3239%3E%3A%3B3%3E873% 3EWSNRCG%3D323337%3A97%3A525nu0mrj

Oh well,,,Gave me a Chance to Do a COMPLETE Rebuild...Everything NEW!!!:w00t:

Good Luck with it:beer

[Yamahondaman]

ain't gotta worry about cold seizer down here !!! 64 deg. I LOVE IT !!! also i run 32:1...sand drags ... 40:1 "the leaner the meaner" !!!! :-)

[2XTREME]

mwke,
Man!OOUUCCHHHH!!! I hope mine don't look like that.:D
X

[2XTREME]

Its a little hard to diagnose over a message board, but unless you started it up and immediately ran the crap out of it while it was still cold, Id have my doubts about a cold seizure. Mine has suffered through many Ohio winters. In my long term relationship with my Z, if it was running good, and you had been riding it a while, and plug looked fine, and then it later seized, the first thing Id look at is an impeller failure. When coolant stops flowing, top end gets really hot, which makes it run really really lean. Impeller failures are common, and Ive rebuilt more than one top end beacuse of it.
You Da Man,
TimSr you were exactly right,I finally felt good enough to peel my strepthroat ass out of my chair to go take a look at the Z.I pulled the pipe and looked at the Piston and what I could see of the cylinder wall.Looks like some scarring both in the wall and the piston.It is pretty tough to see though,So I won't know for sure untill I tear the top end off.
I drained the coolant and took the water pump cover off and guess what?????
The Impeller fell out in my hands.Dang,what a cheesy design.
Does anyone Know of a place to get an aluminum one???
Anyway,I said I would post what I found and that is it so far.I am back in the sick chair eating penicillin.
X:cry:

[New2ATC]

Broken impellars suck.. At least oyu know it wasnt anything jetting or cold related..

[Mosh]

a friend taught me a trick on the z pumps.no one i know of makes an aftermarket impellar. so here is what you can do. drill a hole thru the water pump plastic gear.right thru the center of the mounting nub.then position it on the shaft and put the drill bit in the hole of the impellar and drill thru the shaft.then take a small cotter pin and run it thru the hole just like a rear axle hub and bend the end over.just make sure the cotter is wrapped at the center inside the impellar fins.that way they wont hit the sidecase when it spins.maybe (my friend can get a pic up)i know he has one modded in his toolbox ready for a photo.this tric works and holds the impellar on the shaft.

[2XTREME]

I would like to see that pic.
Thanks for the tip.
Thats a money saver also.
X

[TimSr]

A roll pin works better than a cotter pin, though. Im pinning my new ones now before I ever install them now.

[03 ORANGE SHEE]

get a pro design one for a shee, got one in mine, billet !:D

[2XTREME]

Looks like that will work good.Thanks for the pic.
SHEE--What about this billet one you speak of????
X

[Chrisbroeders]

ya gotta let those liquids warm up ive done the same thing

[Yamahauler]

Sorry to hear that man!!!!!

I hope yours doesnt look like mine when she Siezed in June...1 Tank at 30:1 on Fresh Piston and Head:mad: Crank Bearings went:mad:

Oh well,,,Gave me a Chance to Do a COMPLETE Rebuild...Everything NEW!!!:w00t:

Good Luck with it:beer

This is off topic....but

What causes the pitting on the Cylinder head when the bearings go? I bought a blown up Tri-Z and the guy said the bearings were bad and it had pitting like that all over the place. I thought maybe a ring caught on a port or something and broke off.

My Cyl head is nice and shiney now though:w00t: Thanks Ronnie!

[2XTREME]

This is off topic....but

What causes the pitting on the Cylinder head when the bearings go? I bought a blown up Tri-Z and the guy said the bearings were bad and it had pitting like that all over the place. I thought maybe a ring caught on a port or something and broke off.

My Cyl head is nice and shiney now though:w00t: Thanks Ronnie!
oooohhhhh!!!!Instant Wood.Nice job,Did he also Shave it to the wrench report specs for ya?
X:wondering :beer

[N5HNY]

This is why I stick with 4 strokes.

After all these years, 2 strokes are still a mystery to me. I have never figured out why they self distruct like they do.

I understand how they work, it just seems like they are sensitive to temp and humidity. It seems hard to get the fuel/oil ratio correct.

I got to admit that they go like stink though. It takes a very big 500 or bigger 4 stroke to keep up with a hot 250 2 stroke.

Good luck and I hope you all get it sorted out. I have learned a lot reading the posts on this subject.

[Yamahauler]

oooohhhhh!!!!Instant Wood.Nice job,Did he also Shave it to the wrench report specs for ya?
X:wondering :beer
He shaved it down enough to still work with pump gas. perty sweet

[2XTREME]

This is off topic....but

What causes the pitting on the Cylinder head when the bearings go? I bought a blown up Tri-Z and the guy said the bearings were bad and it had pitting like that all over the place. I thought maybe a ring caught on a port or something and broke off.

My Cyl head is nice and shiney now though:w00t: Thanks Ronnie!
Which bearing? Wrist pin or crank?Just curious because I have had a light growl when I turn the engine over really slow since I bought it.I may have a bad bearing also.
X

[2XTREME]

O.K. I just pulled the top end off and inspected the damages.I am wondering if there is yet another issue with this Z just because the dammages are so focused around the intake side of the piston.maybe this sets off an alarm for some of you guys.This cylinder has the extra port on the intake side from the wrench report.This is the first time I have been into this motor and seen the terrible port job.Let me know what what you guys think.Also look at the dome of the head and all the pitting.This must have been previous damage because this oversize piston is un-touched on top of its dome.Nice-I love when people do half ass jobs.
Anyway I would appreciate some more input so I can corner this problem.
Thanks guys,
X
http://img244.imageshack.us/img244/8842/topend005small6vx.jpg
http://img244.imageshack.us/img244/6435/topend007small1rg.jpg
http://img244.imageshack.us/img244/3295/topend011small2hu.jpg
http://img244.imageshack.us/img244/7550/topend009small0kj.jpg
http://img244.imageshack.us/img244/8697/topend008small5bw.jpg
http://img244.imageshack.us/img244/7751/topend016small28ln.jpg

[Yamahauler]

Which bearing? Wrist pin or crank?Just curious because I have had a light growl when I turn the engine over really slow since I bought it.I may have a bad bearing also.
X
He said it was the crank bearing, and it does have a little bit of play. I dont know if the wrist pin bearing was bad though, When I bought it, the motor was torn completly apart, cases and crank were split, and he didnt give me the old piston.

[TimSr]

O.K. I just pulled the top end off and inspected the damages.I am wondering if there is yet another issue with this Z just because the dammages are so focused around the intake side of the piston.maybe this sets off an alarm for some of you guys.This cylinder has the extra port on the intake side from the wrench report.This is the first time I have been into this motor and seen the terrible port job.Let me know what what you guys think.Also look at the dome of the head and all the pitting.This must have been previous damage because this oversize piston is un-touched on top of its dome.Nice-I love when people do half ass jobs.
Anyway I would appreciate some more input so I can corner this problem.
Thanks guys,



Thats what your typical seizure from overheating a TriZ looks like. Basically the piston swells until it gets stuck, and when it cools back down it becomes loose again.

The nics in the dome are from a prior mishap. Youll come to find that probably half the TriZ heads out there look like that. If it cuases a difference in performance its a lot more in theory than in reality, because I cant tell the difference. Buff it up a little so its not too ragged, and dont sweat it. As for the cylinder and piston it looks like its time for a bore job. I highly recommend sending it right to Wiseco, where you will have full confidence it was done right.

[Mosh]

i would pay real close attention to flushing out the crank case.make sure there is no up and down play in the rod and crank bearings.if so,you might have to rebuild the crank.once an engine seizes like that,i always worry that debris gets wound up in the crank bearings.if no play is felt in the crank,i would flush it out with some brake cleaner and blow air in the crank case.do that alot,then fill the whole crank cavity with 2 stroke oil and let it sit,then turn the motor upside down and drain it after a day or so.these are just careful steps you can take to keep metal from trashing your new top end job.oh yeah tim is the (friend that taught me the z water pump trick).thanks tim.

[Mosh]

get a pro design one for a shee, got one in mine, billet !:D
how did you get a banshee pump to fit the z.the shafts are longer on the banshee correct? i have both pumps on the bench and there is quite a bit of difference. does the impellar fins facing the opposite direction affect the cooling?i am curious:crazy:

[TimSr]

how did you get a banshee pump to fit the z.the shafts are longer on the banshee correct? i have both pumps on the bench and there is quite a bit of difference. does the impellar fins facing the opposite direction affect the cooling?i am curious:crazy:


Thats my question, too. Id switch to a billet in an instant if I could find one to fit. The Banshee fins are on the bottom side of the impeller, and Id like to know if you actually installed one and have it working or if this is speculation.

[2XTREME]

Do not buy this from Pro Design Direct.They are $80.00 plus freight.I just bought a new pro Design in package off of ebay for $59.95+$5.00 in freight.I will try it and see if it will work.I am sure it will work,Orange Shee is using one now and MWKE,just ordered one also.
At least I hope it will work!!!!!
X

[hoser]

Read all of these in your spare time http://12.215.122.222/jetting1.htm

[sirceo26]

Originally Posted by 2XTREME
I am definalty gonna richen it up now.Do you think I need to play with jetting or just richen my fuel.I use synthetic and mix 50:1. I have been doing this for more than 10 years and have never cold seized one.Then again I have never been out in 0 degree weather with any of my 2-strokes.
X
If its really cold seize... it bothers me that it was losing coolant, thats overheating.

Sure a hot piston expands faster than a cold cylinder sleeve, but yall, realise that cant work that way. The CTE for both steel and aluminum are around 0.000006" per degree Farenheit and if the cylidner is cold and hasnt expanded inward, that leaves more clearance for the piston to expand. 757 degrees F would suck up 0.005" piston to cylinder clearance, but theres no way the piston will heat that much and not transfer heat to the cylinder, especially when there is more surface area in the cylinder to take heat than on the piston crown. Secondly, a cold cylinder means more clearance, not less, so its less likely to seize with hot piston and cold jug than if both are hot.

but its a good sounding story to those less experienced....


Since this happened, Id be tempted to see how much the premix oil can be increased before fouling a spark plug and then maybe reduce premix a little. Itll slobber like a drunk at 20:1, might try 30 or 35:1 and then monkey with the fuel. Since the plug is reading about right on as far as fuel, increase premix till it reads darker on the plug from oil.

Thing is, cant let the premix foul the plug or the fuel will look rich when it really isnt.

That extra oil might not help if the cylinder is too cold. Id either block the radiator off if it has one, or wrap the cylinder with insulation and make sure its warm. Might even have to wrap the header of the expansion chamber to keep the exhaust warm. Id want to see at least 150*F on the outside of the cylinder, my R runs 180 normally, which is about the same as the radiator water.

Sorry I cant give you anthing more specific, I dont know the engine that well.

Time to rebuild the top end and make sure its all up to snuff.
Last edited by TeamGeek6; 12-07-2005 at 08:47 PM.








Are you saying to fix jetting with increasing or decreasing oil? everything ive ever read on jetting says not to do it that way. for one increasing the amount of oil actually decreases the amount of gas going into the cylinder, making the fuel to air ratio leaner

[cavemanbob21]

Someone and ill try and find out who makes a brass impellar for the Z and they are indestructable we put one in my buddys ice bike no problems since.

[ATC-Eric]

This is the only aftermarket impellar produced.......

http://www.3wheelerworld.com/showthread.php?90523-Billet-Water-Pumps-for-the-Tri-z/page2


Picture and info on page 2. Tested and true.

[SWIGIN]

my LT250 cold siezed on me once in winter. Then i blocked of most of the rad with thin plastic and never had a problem again.

something to think about.