Cant figure it out

[dusty_v141]

i need some input on my jetting guys. I have fmf fatties, mx porting, mikuni vm 28mm carbs, foam filter with no lid, + 5.5 timing, and stock ported reed cages with stock reeds. It runs awesome from idle too 3/4 throttal. after that it falls on its face. i have tried the needle in every spot and every main from 250 too 380. its ran the best with a 330 and the needle in the second clip from the top. i cant figure it out and im about frazzeled lol. if someone could help me it would greatly apreciated. im about 1200 feet above sea level and the temps are ranging from 70-80 at night too 100-105 during the day.

[AKheathen]

how is it above and below 330? does it sputter, bog, fall flat? check your pickup gap clearance, grounds, coil, caps, reeds, etc. it sounds like it's probably electrical or reeds. what fuel do you run?

[dusty_v141]

im running 32-1 93 pump gas and yamalube r2 oil. i checked the pick up gap last time i checked my timing but its been a little while so it way have come lose. all the electrical componets are stock from 87 so it may be time too start replaceing them. the stator is still puting out enough, im wondering if my coil is getting weak. above 330 it feels like its rich it wont pick up and go it just falls on its face. below 330 its real zingy. well its zingy around 300 and down 310 too 330 is all about the same feeling. i have 125 psi of compression also. thanks for the help

[dusty_v141]

come on guys i wanna ride so bad but im tired of tryin too jet the damn thing lol

[GrMeyer]

Plug chop!!!!!

Check and make sure your gas cap is no clogged.

Pull the pet cock out and look and clean the screens.

Do you have good spark?

 

 

You should be able to tell the difference from 250, 300, and 330's in the bike. If you cant then something is wrong. I would throw the 330's in and pull the choke. If it gets worse then your rich. If it gets better then your lean.

 

The air screw is most effective between idle through 1/8 throttle. The pilot (slow) jet is most effective between 1/8 through 1/4 throttle.

 

The jet needle is most effective between 1/4 through 3/4 throttle.

 

The main jet is most effective between 3/4 through wide-open throttle.

 

 

[WAY2MANYTOYZ]

come on guys i wanna ride so bad but im tired of tryin too jet the damn thing lol

 

I would check your ignition coil. I battled a very similar problem for weeks because I had a coil that was just slightly out of spec. I really didn't suspect the coil though because the Clymer only talks about low end probs with a bad coil.

[toytech]

come on guys i wanna ride so bad but im tired of tryin too jet the damn thing lol

 

we had a buddys doing the same thing and we put a coil on it, fixed it, but the coil resistance checked out fine primary and secondary sides, we couldnt figure it out so we started switching parts off mine and when we got to the coil it fixed it

[dusty_v141]

thanks guys im going too get a new one i just got too wait on some money lol.

i cant decide if i want a stock one, a dynatech one, or a nology coil one thought.

[GrMeyer]

thanks guys im going too get a new one i just got too wait on some money lol.

i cant decide if i want a stock one, a dynatech one, or a nology coil one thought.

 

The Cheapest one!!!

[dusty_v141]

lol i hear ya man

[sheeban]

I would really suggest trying new plug caps, my cub drove me crazy and the problem was a 10 dollar set of caps.

[sheefreak]

I would have to agree, sounds like a possible electrical problem.

 

If you have not done so I would eliminate your tors system as well as check all your connections, ground, etc. I had one act just like you are describing and it turned out that someone had taken the tors stuff off of it, but when they grounded the red/white they used a bullet connector and it was getting oxidized from wet rides etc. it was just enough to make it run like crap from 1/2 to 3/4 and on up. It would start first kick, rap out nice while in neutral, etc. I cut it, hard spliced, and shrink wrapped it and runs great now.