I just bought an 87 quadzilla with a Trinity built motor, Mikuni VM 44 carb w/ K&N filter, and a Bills pipe. The quad has tons of torque but when going through the gears in a drag race the engine will shut down when the rpms get in the upper mids, mostly in 3rd or 4th gear. Sometimes if I have enough momentum going I can play with the throttle and jump start it back up. I've cleaned out the carb, changed the spark plug (nice brown color) and checked the timing gears. All three marks on the gears line up. A friend of mine thinks it may be the cdi. I do not have any experience with these and the motorcycle mechanics in my area know only how to change the oil in quads. Any suggestions is much appreciated?

 

sounds like to me that it might be the stator. ohm it out to make sure. if its the original it could be on its way out. check out this website, you might get more responses there http://s15.invisionfree.com/LT250_LT...ex.php?act=idx

 

sounds like it running out of fuel

 

the plug is brown at upper mid throttle or idle?
there is the question...

 

IT IS, running out of fuel. Under hard acceleration, it's burning the gas in the float bowl faster then it (gas) can make in down from the fuel ****. I had the exact same problem on my 87 Zilla. Remove the fuel **** from the bottom of the tank and cut off the thin plastic screen that is most likely clogged with 19 yrs of deposits. There are two tubes in there. One for reserve and the regular one. Cut both off and install an inline fuel filter.

When you manage to get it going again (while coasting to a stop) enough fuel makes it's way down to start up again.

Lemme know how it all goes for you

 

wolfman...ru from ct??

 

I'm from CA.

Last night I tried some carb cleaner again but I did not clean the petcock. I wasn't even thinking about cleaning that. Took it out for a few quick runs and it didn't shut down like it normally does but it was sputtering. Sure glad I didn't buy that cdi since they are a little expensive.

Thanks everyone for your input. Tonight I'm going to clean the petcock, gas tank, and carb again and also install that inline fuel filter.

Hopefully for my next trip to the dunes it will be running good. My last trip there I could get the holeshot everytime against all the new Raptors (until I ripped a paddle off my haulers) but when I went to shift into 4th gear, well you could imagine how mad I was. My leg was getting awfully tired from starting it back up.

 

was it good before or is this new to the qad the made could be to rich it will die if it is ti rich on the main , were is the float set at

 

raise the pilot jet,to increase pwk pre-atomization into the flow bowl,that will make disapear that sputtering,
and you can raise needle .010 or .020 to see if the mid-range is on the lean side or not.
or you sure oil-mix ratio is at the right spot?

 

The previous owner was mixing the gas/oil at 44:1 with Maxima Castor 927 and 87octane gas. I'm using 92 octane and some Yamalube 2R I had leftover mixed at 40:1. I did find out it was sitting for a long time so I'm cleaning everything and overhauling the carb. Then I can start with the jetting.