Engine not reaching top end speeds

It's probably an airleak somewhere... maybe at the oil seals... fuel starvation can be one of the symptoms of an airleak. I'd check for airleaks first before doing anything with the carb... :)
 
Technocyclist said:
It's probably an airleak somewhere... maybe at the oil seals... fuel starvation can be one of the symptoms of an airleak. I'd check for airleaks first before doing anything with the carb... :)
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I don't know where to check. Everything looks fine. I still say his welding in and around and on the brackets of the engine messed it up..
 
Mopedamauter79 said:
I don't know where to check. Everything looks fine. I still say his welding in and around and on the brackets of the engine messed it up..
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Yup... probably the welding method melted the oil seals or made the oil seals popped out. It's easy check, remove the clutch cover and the magneto cover, and you can see if the oils seals are still ok.
 
o sorry i though it was mph,its kph for you.
well check the seals and seal everything up.
check gas lines and filters.
35kph is like 20-22mph i think.
mine did that when there was a airleak near carb.
and my gas tank was lower than carb.
i fixed and now i go 32mph+
 
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I discovered the problem purely by accident. I adjusted the screw on the side of the carb ever so carefully to lower the rpm and then jumped on the bike it took off like a bat out of ****. I was like wow! So I took it up and down a long street and got my cell out and connected with a gps satellite and I clocked the engine reaching speed up to 42km. Sometimes even touching the screw would get the motor go fast. So it's just a matter of ever so carefully fine tuning the carb to get it just right! I never thought a carb had that much of a impact on the overall performance of the engine..

I now call my engine the little engine that could!
 
the screw on the carb is just for idle not for when throttle is applyed,it should not have that big of a impact on performance besides idleing and coasting without throttle.
are you sure youre not bumping the priming button when you touch the screw.
touching the screw should not make it go faster.
and sure if you set the idle high it will take off and go faster.

and 42kph is only like 25mph,but its still a good speed

my idle set screw is set to idle low and i still go upto 32mph+
but i usually like to cruise around 20mph
 
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Cabinfever1977 said:
the screw on the carb is just for idle not for when throttle is applyed,it should not have that big of a impact on performance besides idleing and coasting without throttle.
are you sure youre not bumping the priming button when you touch the screw.
touching the screw should not make it go faster.
and sure if you set the idle high it will take off and go faster.

and 42kph is only like 25mph,but its still a good speed

my idle set screw is set to idle low and i still go upto 32mph+
but i usually like to cruise around 20mph
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I lost the primer button a long time ago and I have brake bolt snug in there very well and has lasted all winter. So yes I'm dead positive. I had stopped at the store and adjusted the screw just a tad and when I got on the bike again it went up into the 40's. I thought the same thing that it only effects the idle speed but yet it me playing with it was the direct result of the engine going faster. I did nothing else to it. That was the only thing.
 
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The screw is not fitting tightly and when you play with it, it makes the engine leaner or richer depending on how much air it leaks.

I would remove the screw, get some Rector Seal or similar substance (the stuff the use to seal up threads on gas and plumbing pipes) or even some teflon tape and seal the threads so it won't cause you any more problems.
 
im lucky my engine kit from gasbike.net came with 2 of everthing including carb idle screws.i ordered a new carb because i broke a tab on it,there not much money$12,i sugest you get a new one or find a bolt/screw that fits that hole,and seal it.
 
sounds like the carb is messed up ...i would order a replacement carb since they are
cheeper then the engine...if that doesnt fix it then order a replacement engine core
 
Bikeguy Joe said:
The carb can easily be fixed with just a few minutes time and some patients.
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I've run out patience at this point. The tape trick worked for a day so it seemed. Then again I didn't really push the engine. The motor will work fine one day and then not the next. I play with the carb and then i works fine for 30 seconds then slows down and bogs. It's always using up alot of gas. Much more then it should and did before. This really pisses me off. It worked when I brought it to my so called buddy to have him make a new mounting system and I get it back and it's all screwed up and not acting right. I've run out of idea's at this point as nothing I do seems to work permanently..

Something inside is blown or the engine is just cooked.

My so called buddy denies he could of done anything to the motor whether it be accidental or on purpose or even not realizing he did anything. The fact is the motor worked before I brought it to him. I get it back and it's not working right. So I basically told him to go screw himself and I didn't need people like him in my life.
 
my bike had a wot bog and it was the length of the fuel line that solved my prob. the shorter the better i have found to be the key.
 
philymitch said:
my bike had a wot bog and it was the length of the fuel line that solved my prob. the shorter the better i have found to be the key.
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Hmm. Well I have spare fuel line lying around. I can always cut a smaller piece. I can't see that being the issue as it never effected the motor before. Either way I can give it a shot.
 
I have not read your thread.

Float set right ?

Is carb level ?


Trying to help...POPS
 
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I have a couple of ideas check your engine over for black oily stuff that might be coming out of the gasket mating surfaces cylinder base, intake, head, and the crankcase if you see any sort of black oily residue that tells you that you have a gasket leaking and you will need to fix that by replacing the gasket. Look under the ignition cover and under the clutch cover at the main seals for the same oily poo if its there then that seal is leaking and will need to be replaced.
For your carb find out what size of man jet should be around 0.070 mm or 0.65mm the hole needs to be exactly round and true. You needle needs to be tapered up by the clip grooves at .070 thousands and taper to 0.068 thousands. at the pointed end. Most engines use the #2 slot down from the big end of the needle.
I also seal the carb to the intake with silicone you can see how i do it in the classic posts.
The wiring needs to be well insulated no single piece bare of wire can tough any part of the frame.
Your spark plug should be more of a brown if you idle it for long it will look more black an brown.
I don't know if this will help but its the things I would look at first.
Norman
I didn't read all the posts on this so I might of repeated something that has already been said.
 
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