200s Fresh Bore, Smoking Quite a Bit??

[mike84bigred]

Just rebuilt my 200s. Was bored over, new piston +rings obviously. Also did the valve seals. Just got it back running a little bit ago. Started it up, and other than it running a little rough, probably carb adjustments, all was good, until about 4-5 minutes in when it started smoking pretty good. After I completely filled my garage with smoke, I shut it down for a few minutes. I started it back up, and same thing, started smoking again after a few minutes. Its been a while since I did a bore but I don't ever remember this. I have had it running about a total of 25 minutes and its still smoking. Plug is carbon fouled but not wet. Do the rings need more time to set, or do I have other issues here?

[atc007]

I think your exhaust is filled with oil from it being whooped before you rebuilt it. That's why it's smoking after coming up to temp. Go ride it,run it. Don't lug it or over rev it. Check your oil. And after an hour or two,all will be clear if you did things right inside. :)

[NeverLift]

I think your exhaust is filled with oil from it being whooped before you rebuilt it. That's why it's smoking after coming up to temp. Go ride it,run it. Don't lug it or over rev it. Check your oil. And after an hour or two,all will be clear if you did things right inside. :)

Agreed but I would do a compression test before you do this. If nothing else it's a good reference if you have any issues down the road.

[shortline10]

What brand piston kit did you use ?

[mike84bigred]

Im not sure off hand. Had G&H do the work.

[mike84bigred]

Shindy brand piston

[fabiodriven]

Bill's theory is very sound and I hope for your sake he is correct.

[mike84bigred]

Me too. Dont know what else it could be. I mean I had the valves out wh enough I did the seals and they looked fine. Piston was matched to the bore. What else could it be?

[86T3]

You didnt use synthetic oil, did you?

[mike84bigred]

No synthetic oil. Regular 10w-30

[atc007]

You can run syn in this fresh engine till the cows come home. You'll never have a problem. And I would recommend it strongly if you pulled the clutch cover,cleaned your strainer and crankcase?? Hopefully you did! If not you have work to do lol ! If you want reassurance your top end is sound. Pull the breather hose ,if it's smoking out your crankcase. You have a top end problem. But if you're sure you didn't pinch a ring going together,you should be fine.

[mike84bigred]

No I did not pull the clutch cover. Had the oil draining for about 4 months so I figured most of it would have dumped out, but the strainer was not cleaned. No smoke from the crankcase breather tube though. If I pull the plug out after its been running, it will smoke a little but figured the new parts will smoke for a bit.

[RIDE-RED 250r]

Just to add my $0.02 to all of the good advice already given: I did the topend on my ATC110 with a cheap ebay piston about 4 years ago. Like yours, it smoked initially after the rebuild nearly as much as it did before. But the more we ran it, the better it got. Now it doesn't smoke at all. In point of fact it runs so good now, my boy smoked the clutch pack in it! LOL!

Work work work...always something! ;)

[atc007]

4 months is a great drain! But I would tear in and clean the strainer out. There are manuals on here if you haven't done one before. Also,I Always flush the engine while ANY cover is off. Gas is what I've always used,,diesel or kerosene if that makes you feel better. Then ether as my last clean up. Starting over fresh again. Get all that grit out of there and that top end will last forever with a fresh oiled air filter and clean oil,of any kind :)

[mike84bigred]

I ran it yesterday with basically only the things to make the engine run. Have to put the air filter and gas tank back on and get the carb adjusted right. If you turn the fuel/ air screw in, is that more air or fuel? After I get it all back together, ill bomb it around the yard and see if it clears up. Im hoping the rings may have not quite set yet or like Bill said, left over oil in the head.

[DohcBikes]

If you turn the fuel/ air screw in, is that more air or fuel?

Hey that's a good trick question!

It is neither, :D

Its a fuel screw, in for less fuel (lean) out for more fuel (richer).

[yaegerb]

Alot of good info. I would think its exhaust is full of oil or rings need to seat. I have also seen this problem when you don't properly stagger your rings on the piston. I trust you staggered all the ring gaps correctly?

[mike84bigred]

Yes, I had the shop manual present when setting the ring gap locations.

[RIDE-RED 250r]

If the fuel/air screw, (AKA: idle mixture screw) is between the throttle slide and the engine it regulates fuel at idle. If that is the case turning it out (counter clockwise) it will enrich the idle mixture.

Conversely, if the idle mixture screw is between the throttle slide and the airbox it regulates air at idle. Turning it in (clockwise) will enrich the idle mixture.

Most 4-strokes (especially older ones) have a fuel regulating idle mixture screw, and most 2-strokes had/have an air regulating idle mixture screw.

Your 200s should have a fuel regulating idle mixture screw as DOHCBIKES said.

[mike84bigred]

Ran it again today. Ran real good but once again after about 4-5 minutes it started smoking again. I dont think it was as bad today. Borrowing my father in laws compression tester. Ill post the results when I figure it out.

[mike84bigred]

So unless the tester doesn't work right, I can only get 120 psi max out of it and that's after like 10 + pulls. Isn't it supposed to be about 160?

[Thorpe]

Did you hold the throttle wide open when testing your compression?

[RIDE-RED 250r]

Alot of folks seem to think there is a universal compression number that all engines should get. But in my years of wrenching on everything from my wheelers, to sleds and dirt bikes I have found there is no set number that applies to any and all engines.

120 psi may be fine for your engine. I would try to get ahold of some service specs and see what that says compression should be before condemning the numbers you get.

And as Thorpe asked, throttle wide open? It does make a difference. If you don't hold the throttle open, you are restricting how much the engine can take in and deflating your compression reading.

[mike84bigred]

Its been some time since I did a compression test, so I may have forgotten some of the rules. I know your suppose to check it with a warm motor, so I let it run a few minutes, but I did not hold the throttle open. I guess I also gave to figure that the piston and rings aren't broken in yet so low compression and being a bit Smokey may be normal for now. Just I live in the city and really need it not to smoke if I want to beat it around the yard. Ill finish putting it back together, and once my arm heals, because the decompressor cable is broken, ill put some hours on it and see what happens I guess.

[barnett468]

You can run syn in this fresh engine till the cows come home. You'll never have a problem.


Actually, you should NOT run synthetic “till the cows come home.” during break in. After that, you can run it till the cows are filet's on your plate and longer.

Amsoil as well as other companies recommend using non synthetic oil for initial break in. They have done testing which shows using synthetic oil for break in can increase the time it takes for rings to break in or prevent them from fully breaking in/sealing at all.

Amsoil only makes synthetic oil, so for them to tell people NOT to use their product seems to speak for itself imo. I also have personal experience with this.


Excerpt from Amsoil article.

"Breaking in a new engine is one area that petroleum oil is better for than synthetics.

…we recommend you run the factory installed petroleum oil for about the first 500 miles.

…these are our recommendations based on engineering studies and our extensive knowledge of this topic."

http://www.synthetic-oil-tech.com/d.cgi/1124190/converting_to_amsoil.htm


Although a percentage of certainly do eventually properly seat when synthetic is used from the beginning, an increase in the occasional seating problems has been proven when synthetics are used for break in. Knowing this imo as well as in Amsoils opinion, it seems like a simple, reasonable precaution to use non synthetic oil for break in.



Here's my avatar. I named her Bacon. Isn’t she cute?

Hi, my name is Bacon Aren't I cute.

http://t0.gstatic.com/images?q=tbn:ANd9GcTDheK_NT7A9cIdJnV_1Pg7lGbLDWNu5 AVQnY60FToKElt_Wip72n1nHA

[DohcBikes]

Yes do the compreesion test throttle wide open, but honestly it will build pressure anyway. The most important thing is that you check until it stops goin up.

You need to do another compression test. If its at 120 warm after a rebuild, something ain't right. If you do get 120 with the throttle wide open, warm, I'd be doing a leak down test as well.

As barnett suggests, synthetic oil has been proven to be inferior for ring break-in.

[barnett468]

.
Hello Mike84bigred;


Typical post Model T, non high performance, normally aspirated gas vehicle engines have a cylinder cranking pressure of around 135 - 140 psi. 120 would be an extremely low number and not normal for any of these engines. In my experience most engines fail to run below 90 psi and run slowly/poorly at less than around 115.

According to the manual, your compression should be 156 psi plus or minus 14 psi. This means that if it is below 142 psi, Honda recommends repairs. This number is also at sea level. You will loose around 5 psi in cylinder cranking pressure for every 1000 foot increase in elevation. In other words, if you are at 3000 ft, your psi should be 15 psi lower than the Honda recommendations. If it's higher its a good thing. See free online manual in the link below.

http://www.atcmanuals.info/


One problem is that different compression gauges can EASILY vary by 20 lbs. Typically, the more expensive they are the more accurate they are. The length and id of the gauges hose can also affect psi. It is best to use a good gauge and use the same gauge every time so your results remain consistent.



Here's my avatar. I named her Bacon. Isn’t she cute?

Hi, my name is Bacon Aren't I cute.

http://t0.gstatic.com/images?q=tbn:ANd9GcTDheK_NT7A9cIdJnV_1Pg7lGbLDWNu5 AVQnY60FToKElt_Wip72n1nHA

[mike84bigred]

Well I dont live on top of a mountain but I'm not sure where I am as far as sea level, so not sure if elevation is a factor or not. The gauge itself is only a harbor freight cheap gauge, so I guess there's a chance it may not be 100% accurate. One other thing is the cable for the decompressor is broken, so I'm pulling it with no decompressor. I have it tied in place where I think its supposed to sit with a zip tie temporarily. Ill try another test soon.

[barnett468]

Well I dont live on top of a mountain but I'm not sure where I am as far as sea level, so not sure if elevation is a factor or not.Well, google says your elevation is 571 ft, therefore your compression will be .5 x .571 = approximately .2855 psi less than it would be if you were in a row boat. Please be sure to factor this in.




The gauge itself is only a harbor freight cheap gauge, so I guess there's a chance it may not be 100% accurate.Your guess is correct. http://www.freesmileys.org/smileys/smiley-laughing013.gif (http://www.freesmileys.org/smileys.php)




One other thing is the cable for the decompressor is broken, so I'm pulling it with no decompressor. I have it tied in place where I think its supposed to sit with a zip tie temporarily. Ill try another test soon.Did you tie it so it is open or closed?



Here's my avatar. I named her Bacon. Isn’t she cute?

Hi, my name is Bacon Aren't I cute.

http://t0.gstatic.com/images?q=tbn:ANd9GcTDheK_NT7A9cIdJnV_1Pg7lGbLDWNu5 AVQnY60FToKElt_Wip72n1nHA

[mike84bigred]

I'm not positive, but I think its where it would closed. It never worked so I'm not exactly sure and dont know how you would be able to tell.

[sledcrazyinCT]

I'm not positive, but I think its where it would closed. It never worked so I'm not exactly sure and dont know how you would be able to tell.

If it were me I would leave the decompression lever ALONE do not attempt to hold it in place with wire. Is this how you have been riding it around after the rebuild?

keep us posted

[DohcBikes]

There is basically no way he's been riding it with it tied open or closed. It may be tied up, but its not holding that valve in any certain position if the ngine is running.Think about that for a minute.

You are low on compression for some reason. Continue to search for the reason.

[barnett468]

I'm not positive, but I think its where it would closed. It never worked so I'm not exactly sure and dont know how you would be able to tell.Hi bigred;

Easy deal, if it is open even a little you would hear air puffing out of it if you listen closely.




There is basically no way he's been riding it with it tied open or closed. It may be tied up, but its not holding that valve in any certain position if the ngine is running.Think about that for a minute.Hmmm, I thought, and pondered, and consternated [not constipated] over this potential conundrum for many a second and have come up with the following answer. In this rare instance, you are actually incorrect my friend, although it is unlikely that someone would not hear a compressor type sound from a partially open decompression valve and continue to ride it thinking the sound is normal. I have actually ridden several bikes out of necessity with the decompression valve partially open. I have also seen and heard others do the same.

Back in the Jurassic days, this was an occasion prob with desert racers or races in the mud. The valve Mechanism would get full of sand or mud, they might stall their bike then pull the cable to start it and the gunk would prevent the valve from closing.

[DohcBikes]

Lol yes OK youre right. I suppose I was figuring that the noise would tip the person off, and soon after would be shutting it down, but I digress.

[barnett468]

Lol yes OK youre right. I suppose I was figuring that the noise would tip the person off, and soon after would be shutting it down, but I digress.

This is not in reference to the op, however, in general I have found that when dealing with such things, it is best to keep in mind the mentality/mind set and/or level of experience of some of the tricycle riders and therefore NEVER assume. http://www.freesmileys.org/smileys/smiley-laughing013.gif (http://www.freesmileys.org/smileys.php)

[mike84bigred]

I have been beating it around the yard the past couple of days and for the most part the smoking seems to be clearing up. Also did another compression test on it and was getting between 150-160 psi, so maybe everything is starting to settle. Going to change the oil sometime soon.

[hogmuffin]

I had the same issue after I rebuilt the top end on my 200x. Smoked real bad after the initial startup. After a few hours of riding it cleared up. Hasnt smoked a bit since. I figured it was just the rings seating but I never thought about the exhaust being full of crap. Could have been either one I guess.