1/4 throtttle under load

R&S Polishing

New Member
Jul 5, 2008
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Oregon
just finished the top end re build on one of my daughters blasters i did the diy 1mm port job that ken Oconner has video to re assembled everything and fired it up today.Great!! i now have 3, 15minute heat cycles in it and took it for a short little ride down the street when i get to 1/4 throttle and give it some more it does nothing to increase rpms (almost like a throttle stop)? X(tried to figure this out 1 attempt out of 15 or so at giving it more throttle it responded some but just momenterly than back to the throttle stop thing am i just way too lean or what??? going to pull carb apart tomorrow morning and check the needle position and spend my day playing BLASTER CARB repair man:o:o:o
 
doesnt bog definatly but i dont hear it poping or sputtering either. sputter would be my answer more than popping? guess i will find out in about 15 minutes thoe...
 
Usually jetting is one way or the other to an extreme. Either it completely bogs off or spits and sputters and is real lathargic.

It almost sounds like an ignition problem. Go back over and check the stator connections and the ground wire on the coil.
 
WOW i was way off... started adjusting the needle went rich and it was worse so i jumped back to the lean side and put it 1 leaner than wher i started (better) but not good enough finished up on the top clip setting and it runs a whole lot better but still has a slight hesitation that i will adress after i have broken the motor in more, it may come around some during break in but not expecting it to change much if any!
 
What all have you done to the carb? I can see where with mild porting you assumed it would need richer. Now you've leaned it with the needle. How is the initial throttle response?

So far I would say you need a smaller main, and maybe a smaller pilot.
 
I am thinking the same smaller pilot and main however the bike is exclusively ridden on the sand (coast) i have 1 larger than stock pilot 32.5? and a 340 main
 
yaeh that is some of the same thoughts that i was having. 340 main is what my son's bike runs in it with a verry similar set up just thought with the porting that would be close to start with but mabe i was jumping the gun a little? next weekend is all duck season so i will be over in your neck of the woods with a SMILE on my face