I'm baffled....power related.

Okay, so my new engine is still in break-in....running a 16:1 ratio. Gets great spark, runs awesome(does bog a little when revved) with no power, as soon as I let out the clutch I can't get going far....now the first day I started everything was fine...my c clip WAS at the 3rd notch from the top, moved it to the 2nd....a little better but no, moved it to the way top, EVEN worse. I have about 119-120 lbs of compression( I rode the bike about 10 mph and popped the clutch TWICE and the reading stayed the same. I've tried 3 different spark plugs, same results. The clutch is NOT slipping, I'm running a SPEED carb(came with the kit). I do have some regular NT carbs I could try(I'd need to steal the gasket) Of course....this is NOT my first build, I've worked out every probable bug EXCEPT trying a different carburetor. Any ideas would help, thanks! Oh, and gas is BRAND new and fresh. No air leaks either.

NT carb fixed it! faulty carb

crassius said:

I've had new engines that ran like that for whole first tank of fuel (about 20miles on that tank), then began to straighten out as the rings seated a bit better. 2nd tank of fuel got 40 or so miles, and 3rd or 4th tank was when it started to run normally.

If it doesn't straighten out, then try thinner head & base gaskets.

EDIT: oops, posts crossed in progress : )

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As mentioned above, it was a faulty carb. I've never had to swap gaskets though. Also, my kit is an upper-end kit, but anyway. Thanks!

Theon said:

120 psi don't seem like a lot from a higher end kit?
Hope it comes up.

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I paid $250 for the kit. Has short intake held on with hex bolts, lots of other stuff too, yeah the carb was crap. I swapped it for an NT carb, started right up and took off like a rocket! I'm running a low profile perfomance air filter, ordering a speed demon exhaust as well.

Yes, the speed carb did have a shutoff valve. The engine ran great when it wasn't under any kind of load(which is very odd because the first few days I rode it it was fine. The bike was very hard to start afterwards. Great compression, so anyway, I took the carb apart, float and everything was fine, I the little e clip on the slide needle was on the 3rd notch from the top....I moved it to the sweet spot which for most people(usually myself included) which is the 2nd notch from the top. Well...it was an improvement but still wasn't the way it was supposed to be. So..in the past I've had BRAND NEW carbs just SUCK(the old dirty one worked better than the new one!) so I pulled all of the innards from the speed carb(float, pin, fork, gasket, etc.) and put them into a KNOWN working NT carb, FIXED. Fired right up, rocketed away. I didn't use the jet from the speed carb, I also have a high performance filter as well. I have a new nt carb coming though as a spare.