83' 250R Piston Siezure Goodness!

[leetwanker]

Well I just bought this bike friday and have ridden it twice totaling about three hours, luckily I was on my way home from a long drive when this happened:

http://i79.photobucket.com/albums/j128/JustinWPB/10-08-06_1740.jpg


http://i79.photobucket.com/albums/j128/JustinWPB/10-08-06_1741.jpg


http://i79.photobucket.com/albums/j128/JustinWPB/10-08-06_1742.jpg


http://i79.photobucket.com/albums/j128/JustinWPB/10-08-06_1743.jpg

I'm not sure what caused it, I was riding it pretty hard at the time though. This is the first 2-stroke bike I've ever owned so I'm not really sure what sort of things I should be keeping an eye on and/or listening for. I will admit I don't really know how to check the oil level in the bike, there is an oil-check screw, do you just unscrew that and if oil comes out it's good? Thanks for any advice.

Justin

[team-red-rider]

THats really just for the tranny but did u mix oil withthe fuel? because it looks as if it was run with out oil for a while!

[leetwanker]

THats really just for the tranny but did u mix oil withthe fuel? because it looks as if it was run with out oil for a while!

Yeah, I'm running Golden Spectro (Synthetic/Petroleum Blend), 20$ for a two quart Jug. I'm mixing two cups (16 ounces) per five gallons. I think that's a 40:1 Ratio?

[gotballs 250r 82]

I run golden 32:1 never had a pro:TrikesOwn blem

[leetwanker]

Should I run a stronger ratio then? The guy I bought it from said he ran a 20:1 ratio, 4 ounces per gallon. And can someone explain the oil-check screw?

edit: I just did the math, I guess he was confused on the ratio because 4 ounces a gallon is 32:1.

[team-red-rider]

hmm how does the plug look? color? how is your jetting?

[team-red-rider]

dont worry about that oil check for now but after u get it running drain it and i think it takes 1qt

[leetwanker]

hmm how does the plug look? color? how is your jetting?

The plug is a dark color and was wet with oil when I dissasembled the engine as soon as it cooled down.

The guy who sold it to me told me it had a 300cc overbore in it, allthough I'm not sure how to check if that's true or not. and it has a Mikuki carb in it. I'm not sure about the jetting.

edit: I'm sorry the carb is a KEIHIN.

[Billy Golightly]

That looks like a cold seizure to me, but you said you had been riding it right? IMO that looks to be the product of an improper clearence for the piston to cylinder wall. Probably from a bad or poor bore job. Also check the corners and edges of all of the ports, the exhaust in particular should be radiused fairly nicely. If its got sharp edges or isn't smoothed out that can cause that also.

[leetwanker]

That looks like a cold seizure to me, but you said you had been riding it right? IMO that looks to be the product of an improper clearence for the piston to cylinder wall. Probably from a bad or poor bore job. Also check the corners and edges of all of the ports, the exhaust in particular should be radiused fairly nicely. If its got sharp edges or isn't smoothed out that can cause that also.

None of the ports have been radiused, looks like it was just bored out and that's it. I just slid the piston in a little bit and there looks to be less than half a milimeter of clearance between the piston and the cylinder wall when I push the piston firmly to one side, though the piston is slightly larger due to the metal being torn up from when it siezed.

edit: I think if you look at the first picture I posted, the exhaust port is on the right, you can kindof tell there's no radius on it.

[jason 32]

well wisco says 3 thousandths clearance- looks like a wisco piston
i use klotz oil its great oil 32- 40:1----- weed wackers run 40:1 these days and there air cooled
looks like no warm up?? did you relieve the exhaust bridge ? what does the wisco paper recommend -- ?2-4 thousandths?

[Tyler]

It's been awhile since I've played with small motors. The clearance was too tight. Wiseco pistons need more clearance than they ask for in the directions. Get the ports cleaned up when it is bored. The details are so important when setting up clearance etc.

[Pete]

I would run more than .003 on the air cooled R motor, especially if its a 300 big bore setup (even more heat0 When I was younger I had an '83 that I went through numerous pistons before I found an engine guy who set it up for .005 and I never had a problem after that.

The problem is the Wiseco pistons are forged and more dense, and they tend to expand and contract a little more than a cast piston, but they are stronger in the same respect.

[leetwanker]

Well I'm disgusted at the moment. I picked up the cylinder to take to the machine shop to have it bored out and it got dropped and one of the two pieces of the sleeve that extend out past the bottom of the cylinder got broken off.

Can you guys help me find a new cylinder sleeve for a decent price being that buying the trike emptied my wallet pretty much? I'd like to go with a 300cc setup wether or not it had it before. Also I'll need help selecting the right piston to go into it.

I'm going to go chain smoke a pack of cigs now to try to calm down, I hate when stupid crap like this happens.


Thanks
Justin

[leetwanker]

Or maybe if someone out there has an air cooled 250R cylinder/piston they'd be willing to sell me that could save me some money.

[MRPoopie]

dont know if this helps but here

http://cgi.ebay.com/ebaymotors/HONDA-ATC250R-ATC-250R-CYLINDER_W0QQcmdZViewItemQQcategoryZ43977QQihZ010Q QitemZ200034556900QQrdZ1

[leetwanker]

Good find, thanks for that. I did a search earlier and didn't see it, could be because I was so pissed off at the time though. I'm currently the high bidder. If I get it I'm going to have to repaint it so it doesn't look like my trike is a junk yard dog. What kind of paint is best for painting heads/cylinders? In my experience the high temp grill paint or whatever doesn't hold up.

[Billy Golightly]

I would just bead blast it if it were me, no paint to worry about then.

[leetwanker]

I would just bead blast it if it were me, no paint to worry about then.

Sand blast? I've never heard of bead blast. My current head has no paint on it though so somehow removing the paint off the red one would be ideal.

[Billy Golightly]

you can use sand, bead blast is the same process just a different media. Usually real small hard beads of glass or sometimes ground up walnut shells, ect. Depends on how how rough of a finish you want or how much of the surface your trying to remove.

[leetwanker]

I'm wondering if I should pick this one up instead?

http://cgi.ebay.com/ebaymotors/1982-1983-HONDA-ATC250R-250-R-Cylinder-Cylinder-Head_W0QQitemZ140038368006QQihZ004QQcategoryZ35595 QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[Air-cooled-R]

welcome to the club. I've broke a few pistons too

[leetwanker]

welcome to the club. I've broke a few pistons too

Yeah, I wasn't bothered by siezing the piston. What really bothered me was the stupid circumstances that lead up to the cylinder getting dropped and broken, it would've been at the machine shop in a few hours and I'd be ordering a piston for it right about now. Now I've got to buy a used cylinder which I can only hope is usable and sit on the bench for a few weeks. Sucks.

[TtownJoeShow]

i don't think your old cylander was 300, well Hondaline 300cc, cause mine has an exhaust bridge!

[leetwanker]

i don't think your old cylander was 300, well Hondaline 300cc, cause mine has an exhaust bridge!

Yeah, quite possible I was lied to, or maybe the misinformation was passed on to him before it was passed onto me? Oh well. Just wanna get it fixed no w. :(

[jason 32]

why dont ya just have it sleeved at the big bore? when they bore them out that far they bore almost all of the stock sleeve tabs out any way

i need to correct my self-- evry 1mil of bore doesnt add up to 8cc.s all the time
because of the cylinder volume!-- a small bore has a smaller volume than a bigger bore so it doesnt add up to 8cc's per 1 mil of bore all the time
sorry people i was tired at the time lol

[leetwanker]

why dont ya just have it sleeved at the big bore? when they bore them out that far they bore almost all of the stock sleeve tabs out any way


I can't find a big bore sleeve for one, also, I think it's cheaper to buy a new cylinder and have it bored out as far as it can go and get a piston for that bore.

Sleeves: 90-140$

Used cylinder off ebay: 22$

The pieces of the sleeve that stick out past the bottom of the cylinder ARE needed, yes? I assume that they're there for a reason.


Guys: please correct me if I'm wrong about any of this.

[leetwanker]

This auction just ended on ebay and I should have this cylinder within a week:

http://www.heintzs.com/parts/100506parts032.jpg

The question is, I just found someone who's willing to sell me what he says is a 300R cylinder, it's pretty beat up and I'm not sure if it's really a 300cc cylinder or just bored out big. Can you guys tell me if I should buy this or not? Here's some pics:

http://i79.photobucket.com/albums/j128/JustinWPB/300R1.jpg

http://i79.photobucket.com/albums/j128/JustinWPB/300R2.jpg

http://i79.photobucket.com/albums/j128/JustinWPB/300R3.jpg

http://i79.photobucket.com/albums/j128/JustinWPB/300R4.jpg

http://i79.photobucket.com/albums/j128/JustinWPB/300R5.jpg

Thanks all,
Justin

edit: supposedly the numbers written on the cylinder are the bore size in inches.

[BigGreenMachine]

How many head bolts do it have?

[leetwanker]

How many head bolts do it have?

Looks like 6 from the picture of the head. Does a genuine 300cc cylinder have more?

[MTS]

Thats a Hondaline 300

[leetwanker]

Thats a Hondaline 300

How can you tell? Is there any way I can know if it's usable before buying it? It looks pretty beat up.

[Somekindofjerk]

Stock bore is 71mm or 2.7953inches
That bore is 2.99inches is equal to 75.946mm

[TtownJoeShow]

you can also tell by the cooling fins!

[MTS]

The bridged Exaust port and the Fins on the head are diffrent.

[BLAZERONE22]

The Hondaline 300 has 7 headbolts. This guy can hook you up with a piston setup. http://www.superiorsleeve.com/