clone not getting rpm's

[Edric10]

hey my name edric10 I have a clone motor tht was built by agk its a stage 3 it was running pretty good but now i cant get no rpm"s out of it i think my carb is to big or its jacked up this is what I got into the motor an only getting 3800 rpm an when i give it full throttle it stall out

14cc flat top piston
billet rod
1:3 rockers
molly push rods
26 lb valve springs
black mamba cam .275" lift 246 duration
22mm mikuni carb
mikuni fuel pump
alumina bullet flywheel
low oil gone
govenor gone

 

[Txpowdercoater]

I would check valve lash

 

[deesel]

What has changed from the way ur motor was before? Just the cam? Ur carb was alittle rich before when i saw ur bike, but that mamba cam should run about the same as ur old cam. Check the simple stuff first like make sure the carb is working right, then verify the cam timing is right and valve lash is correct.

 

[Edric10]

well i check the valve lash twice its at .003 an i started to loose rpm's before i put the cam in thts y i boult it i notice the spark plug was kind of black an its new an the timing should be gud i made sure the cam an crank was dot to dot but this problem was going on before the up grades :scared:

 

[Edric10]

yo deesel u should come check it out when we get out of wrk

 

[deesel]

Yeah i could do that some time this week

 

[roccosbike]

Your running too rich, did you alter the air filter in any way?

 

[iatemeself]

In the mikuni what size pilot and main jet are you running?

 

[Edric10]

130 main 12.5 polit

 

[deesel]

That seems fat on the main. I like a bigger pilot too.

 

[Edric10]

Yo Deesel my number (989)332-3907 hit me up an thts how tht carb came from agk now i still got the carb agk put on the motor which has #92 in it

 

[Mean Dean]

I have a custom built clone we just twisted it to 8800 on a tight budget.

 

[iatemeself]

why a 12.5 pilot ? 15 stock jets are also too lean for your mods, you should try 17.5 pilot jet that could be your problem. Also turn air fuel mixture to stock 2 full turns out.

 

[Edric10]

Yea tried tunning that mikuni lst nite an just wouldnt for me so im gone put tht factory carb with the 92 main jets in it today an see how tht wrk for me if not anybody got any idea's :cursing:

 

[iatemeself]

Well if the factory carb works than you know that something is up with the carbs. I don't think your settings for the Mikuni carb are right. I would try 120-130 main jet on the Mikuni and a 17.5 pilot jet.

 

[Edric10]

Factory carb wit #92 main jet fail got it started 1 time an it ran the same now it wont start it simple i know it is just cant figure it out yet :censure:

 

[iatemeself]

did you change the valve lash or springs? Check that

 

[Hellaslow]

im having the same problem with my gx340 it only turns 3200rpm even tho it should be 5500 atleast... i checked valve lash and even checked jet size... no luck!

 

[125ccCrazy]

did you try moving the needle clip at all? your mid range is tuned with the needle adjustment... it sounds to me like a mid range problem if it starts pulling then pukes..

here is some good info for tuning the carb and what everything does... Mikuni carburetor operation and tuning

 

[Edric10]

ok i just got my mini out of storage so here we go again this is were im at just put a new main jet 120 in an a 22.5 polit in its easier to start now took it for a test run im still only hittin 3300 rpm but it idles real good an start up easy