half a lap and loose most of the power

[stauffracing#4]

we have been trying an air cooled 100cc motor.in stock appearing class.its a high compression motor basic clutch mods race gas.off the line it rips and for half a lap but then almost no power it still finishes the race and the plug looks good?let it sit for even a minute and its back to full power?very frustrating

[Ryki3r]

sounds like compression, or maybe air in the fuel line?

[Nichols Atvs]

Make sure your head bolts are tight and long enough and torqed down 12 -14 lbs had this happen and the base gasket would leak when hot.

[quadscrib]

vent hose clogged? restricted? pinched?

[fcfab]

check you petcock' we went to the trx 450 one because the same thing. It would run low on fuel, but not out.
fcfab
Carey

[THARNESS]

With the extra power of the 100 kit your rear torsion may be too weak. As it heats up it will weaken even more and could cause the symptoms you are describing.
Good luck.

[dblacks]

crank seal?

[tireman43]

Originally posted by dblacks
crank seal?

That's what I was thinking too.

stauff...in your post about keyways, it appears you have a bunch of compression. So I'm thinking crank seals, or gasket trouble.

[stauffracing#4]

thanks for the feedback ill be checking all of these things.i talked to a friend and he had the same problem. bypassed the petcoc and that was it. just wasnt enough fuel.oh yeah the crank seals are new and all gaskets are new.clutch spring is new i also retourched the head bolts after it was run.ill keep ya posted?

[hotquads1]

maybe overheating ,causing detonation.

[stauffracing#4]

well i tried some of the things on this.its just funny but the first time it starts to bogg is when you let off and turn.so i thought it might be a carb issue changed it same results.

[#404's Dad]

Originally posted by stauffracing#4
well i tried some of the things on this.its just funny but the first time it starts to bogg is when you let off and turn.so i thought it might be a carb issue changed it same results.

Had this same issue on an Apex 90 last season when using VP U4.2 fuel, chased the problem all over the place, ended up changing fuel and never seen the issue again....................

[hotquads1]

drop your roller weight about .5 gr and give it a try.
marc

[THARNESS]

This was happening on our new w/c 50 with an OKO carb. I tried two other OKO's and had the same problem. I then switched to the Sunworld and our problem went away. So I guess what I'm getting at is if you are using an OKO carb you might want to try something else. I've had good luck with a 24mm mikuni on our built 90's.

Good luck.