Does this mean that I have a bad cam or valve? Possible cam timing issues? or could other things cause this.

Recently bought this quad.

It would start and idle somewhat, but needed the choke on much of the time. It had a noticeable hesitation off idle, but would rev out seemingly ok.

I assumed because of the choke inproving things that it was lean, so I went richer on the pilot (42.5 to 50) and raised the needle (dropped clip one position) it improved the low speed running in that it would idle well and had good throttle response off idle, but now it has no power on top, wont even rev past midrange. Then went back to original on the needle and still runs terrible, but now backfiring through carb.

Please help...

Thanks

 

Check your valve clearance first. .006 intake and exhaust,could have a tight valve causing problems? PLUS check that the air box inlet tube isn't being partially blocked by the tank! CAN'T remember which year this was a problem?? You can cut a bigger angle on the tube as it sits against the tank and see if it runs better? Hopefully this will give you a start! OPT

 

Wes

I have an 03 Trailboss 330 and it ran much like yours. Took forever to warm up and had a major off idle stumble but idled fine, reved out fine. I wound up purchasing a dynojet kit for it. Drilled the air screw plug set to dynojet specs. They supply a new needle and main jet. I wound up going 2 notches richer than Dynojet specified in the instructions (After consulting with a DJ tech.) but it now starts and runs perfect. Quick warm ups and absolutely no off idle hesitation. DJ stated no need to change the pilot jet as it mostly effects idle. If your valves check out I'd return to the old pilot jet, make sure the nothing is blocked in your carb and install the DJ kit or at least richen the needle and AF screw. Another thing to consider, those carbs are notorius for spewing fuel and flooding when the float height is set to factory specifications. I had to adjust mine lower to stop it from spewing fuel out the vent line and running erradically at time. I replaced the needle valve and seat to no avail and the only cure was to adjust float lower.....just a thought. I hope this helps save you the amount of time I spent with this thing to get it to run correctly.

 

Yes the 325 and 330 carbs were set too lean on the fuel/air screw! Took too long to warm up and some I had to drill out the fuel/air screw plug and open up. Had several that were only about 1/2 turn out and one especially that was completely turned in! I've never been too found of the DJ kits because most of the cost is in the TITANIUM tapered needle and they remark the Mikuni or Keihin jets with THEIR numbers so you don't really know what size jet is in it unless you have a gauge set to measure which I do have! You can basically achieve the same results by drilling the carb slide opposite lift hole to the same size as the stock one and just rejet. Save the 125 bucks or more depending on the model(this cost is for most street bikes) I actually installed one on my own Nighthawk along with a 4 into one exhaust and didn't notice any difference really except more noise! Needless to say,its back stock(except for one size up on the main and pilot jet) and will stay that way! I've installed em on Busas,Gsxrs,etc and still say you can do it yourself without the gimmicks! Just my on Dynojet and PLEASE EXCUSE an old man's ranting and raving! OPT

 

I think I only paid around $40.00 or so for the kit. The single cylinder kit is cheaper than the multis. I do have to agree with you that in most cases you can achieve good results with almost no expendature of cash doing what we like to call the Ghetto jet kit. Drill the plug and enrichen the AF screw/shim needle or change clip position if possible/enlarge slide lift hole. All usally will do the trick. Main jets are usally cheep also. I did that on my 1200 Bandit and left the exhaust stock (Don't care for noise either) Really improved overall drivability and much quicker warm ups. My biggest complaint about the DJ kit is the base settings they give you can be off significantly.