Hi all, just noticed for the first time that my bike hit around 8k or so and hit what felt like a rev limiter. Never noticed this before i upgraded and thought i could get near the 10k or so redline.

Is this a mixture or jetting issue that I am not getting enough fuel (or too much) I went from a 128 DJ main stock pilot to a 132 main /40 pilot with the upgrade. Only really noticed it after i put the new pilot in, which doesnt make sense if that governs flow at low rpm. Slide is drilled and clip is wherever it is recommended out of the factory. fuel screw about 2 1/4 out now. Carby still not as good as when i put the original DJ 300 kit on and think it still needs some monkeying.

Also i am running the free mods, k&N filter, screen removed. Have the stock exhaust with pilot holes drilled throughout to try to relieve pressure. Suppose too much back pressure could be a possibility now at that volume. Anticipating going up to a q4 soon but not there yet. Operation about about 7K just doesnt feel as smooth as I would think it should.

Any suggestions on this one?

 

Your problem is with the main jet and the needle.
132 sounds way too small for the 351. I'd go get a 140-145 main and see how that worked

 

I'm using a 132 main on my 351 and no problems at all.. Will pull to redline.. Though it makes all the power down lower, so no reason to ring it out like the 250.

 

Here are the numbers when I was running the 351 with the stock carb and pipe.
40 pilot jet
2.5 turns fuel screw
Dynojet needle, on the top notch, meaning: leanest setting
140 main

Thanks,
Bake

 

That 1/2" hole is holding back the upper rpm power and is why you run well with the lean setting of the needle.

Ride on
Brewster

 

bake, looking at that graph, its probally best to shift at 7 or so. shifting at the peak of power means you have to drop off more than if you go pass it a bit. yes, it may only mean a tenth of a second or so, but racings racing if your like me.

 

i guess if you were running it down the 1/4 mile,,,, you could shift it at 6,550 if you had an air operated shifter and a shift light.
The average individual will shift when they feel the power drop off,, and then through time learn to shift just before the power drops off.
Riding in the dirt,,,, i dont think anyone has ever used or needed a tach.

 

Bigger bore can pull more vacuum at the nozzle which can pull more fuel with the same size jet. Why in some cases you don't need to rejet as much as you think.

With the cv carb the differential in pressure/vacuum on either side of the carb cnalso change with the increase in vacuum. So if the slide and spring was modded pre bigbore it can be acting a little different.

 

check spark plug
fuel filter

depending on budget bill tm33 will fix it not sure what jets are in it (anyone know)
and a pipe will help