i have an 84 puch maxi and when i go past a certain point at full throttle i four cycles and rattles sorta is this a govenor or is it just the engine?
i have an 84 puch maxi and when i go past a certain point at full throttle i four cycles and rattles sorta is this a govenor or is it just the engine?
I think all engines should work steadily all the way up the throttle without fouling at top revs. The governor engages itself only when you try to overrev the engine at idle run, thus preventing it from breakdown. Your problem might be the lean mixture -- try adjusting the carb to correct that.
I think all engines should work steadily all the way up the throttle without fouling at top revs. The governor engages itself only when you try to overrev the engine at idle run, thus preventing it from breakdown. Your problem might be the lean mixture -- try adjusting the carb to correct that.
This symptom seems to be a reoccuring complaint on the message board over the past almost year and I have'nt heard a satisfactory solution offered yet. For some reason PUCH with the BING carburetor is the major source of the complaint. I have two PUCH bikes with this problen to varying degrees and I distinctly gets the impression that the engine suddenly is fireing every-other revolution rather than every revolution as is normal for a two-stroke cycle engine. All my instincts tell me that when it starts to run rough it is because it has become too rich. Yes, we could start fooling around with main jet sizes, but here in the Good Ol' USA, there are very few sources to purchase them and a set of 6 or so would run the better part of Fifty Bucks and I am not convinced that is the problem. If it is an excess fuel problem, I am wondering if perhaps the float needle valve tip has become worn and is not sealing properly under the conditions of severe vibration at the higher engine speeds and the effective fuel level in the float chamber is too high yielding a too rich mixture. It is NOT a function of exhaust back pressure, clean exhaust, no restrictor, no exhaust system at all, none of these make a difference. It might be something to do with ignition, but a new properly gapped spark plug does not change anything. It might just be that the piston/rings/cylinder have become too worn and the gas leakage is too great, I hope this is not true. I think that there are several of us that would like a final solution to this nagging problem, HELP!
I've never worked on a Puch....but
Tony.... I think you're on the right track ..too much fuel
For a quick check.... run it with the air filter removed to see if it speeds up.. if it does.. then you need to buy a leaner jet.
I can't believe that price ($50 for 6 jets) .. take your jet out and read the number on it.. then e-mail one of the places mentioned here (moped warehouse?) and buy the next 2 smaller sizes.. they shouldn't be more than $2.50 apiece.
Till you try that.. you will just be guessing.
One thing you didn't mention was the spark plug color after running at top speed fpr 10 minutes.... do that.. if it is dark brown, its too rich.. it should be light brown.. but you have to run it wide open for a long time for the color to stabilize.
I am an owner of two puches which had the same prob. of carbon fouling. No matter how lean the mixture was in new plugs were a weekly occurance (the people at the auto parts store were wondering what the hell was this kid doing buying a million L82C plugs). Getting very frusterated I finaly found the most likely sorce of my problems. On a hunch I took apart the air box on my Magnum and sure enough the metal part of my element was rusted out. My theory is, the clogged air filter was acting like a choke and sucking gas out of my jet like a straw. Since then I have took the element out, just to see if I would foul another plug but unfortunitly I have not yet ridden it enough to see but so far the color on the plug looks good.
You say "no matter how lean the mixture was" it would still foul plugs.
.. How did you lean the mixture out?
Mix less oil w/the gas
Be careful
People get confused with the word "leaner"... or "leaner mixture"...
This term is meant to mean the ...fuel to air mixture... NOT the oil to gas mixture.
It is adjusted "leaner" or "richer" by a couple diff. methods
Bigger (richer) or smaller (leaner) main jet.
Raising (richer) or lowering (leaning) the needle on a slide type carb
Turning the idle mixture screw in (richer) or out (leaner) for idle running.
So when I said his mixture needs to go LEANER ..I was NOT saying to put less oil in... I meant to put in a smaller main jet.. (less fuel to go with the air)
however, i have been running a leaner fuel/gas mixture and have not had any problem. I have a minarelli engine on my bike and it asks for 3oz to 1 gal, i have been running 2.8 and sometime 2.5 with no problem. the 2stroke oil and the gas have changed a lot in the last 20 years.
ok here is the real deal about the engine acting like it is on choke at high speeds. the engine is not getting enough air. to fix this eather take out the air filter,take the air box off completely(dont do this cause the engine will act strangely at starts)or go to a smaller jet. if you try these things i gurentie you it will work.
-mike
Fred, no matter what termanology you use putting less oil in qas tank will provide the bike with leaner charictoristics. It is not necessary to be so critical of wording if the info is good.
Sorry... that is not true.
Less oil in the gas means the... gas to air... actually gets richer (because there is more gas, less oil), which is the opposite of what the guy needs.
Example.. (the numbers are off a bit to make it easier to understand)
The air going into the carb is 100% air.
After it goes thru the carb it is 90% air, 10% fuel.
But say the fuel is 95% gas, 5% oil..(20 to 1)
Then overall mix is.. 90% air.. 9.5% gas..and half a percent oil.
Then cut the oil in half (40 to 1)
Now the overall mix is...90% air.. 9.75% gas.. and quarter a percent oil.
So you can see there is now more gas to the same air... it's RICHER.
When knowledgable people say "lean it out", they mean put a smaller jet in... not decrease the oil.
The reason a rich engine will bog down and build up carbon is an excess of oil. The oil in the mixed gas does not burn nearly as well as the actual gas, so the larger percentage of oil you have in you mixture harder time the engine has firing which in the root of the bogging in the first place. Oil in the engine, while turning over acts like dead wood, it holds the RPMs back. If your bike is running rich a non-evasive way to fix the problem is to simply add less oil when you fill up your tank. Since the engine can now cycle with more ease. The logic you used in your last post sounds like something you would here on an infomercial, the figures look good but in truth it's a whole load of BS.
Don't Argue With Fred. FRED KNOWS EVERYTHING!!!!
Remember the original question revolved around an engine that seemed too rich (gas)... putting less oil in raises the gas percentage and would make that guys situation worse.
Leave the oil alone and put in a smaller main jet, problem solved.
There are several books on 2 stroke tuning that will agree with my scenario.
Experts do not "tune" with oil ratio.
Want to post in this forum? We'd love to have you join the discussion, but first: