ok, i got a graydon pipe and i run it with a uni filter with no lid. i have used every jet up to a 195 and it IS STILL LEAN!!!! i can not richen it up. the plugs are white as a ghost. tomorrow i plan on trying a 200 but if that dont work i dont know what to do. i ahve moved the needle clip to the 5 position also. PLEASE HELP ME

 

also, when i had the #195 in it it ran beatiful i thought, it had all the power in the world. but when i let off the gas it would back fire. i called graydon and they told me i am way to rich, i called my local bombardier shop and they said i am to lean. i am so confused. PLEASE HELP ME!!!!!

 

Make sure you dont have a fuel flow problem,pinched gas tank vent line,clogged fuel filter(on petcock in tank)
Try running it at night,if the head pipes glow,you are lean.
Make sure you run it hard,then check the plug.
Is it just lean at low idle,could be a pilot jet or air fuel mixture screw ajustment.....
Unless you have something wrong with the carb
Other than that I dont know...
Jeff

 

If the plug is white then there is no doubt you are lean. Keep going up till it looks a nice golden brown color. Like Jeff said, run it hard, really hard, unless you feel your way off. to get a good reading. I think the secret to going fast, really fast,is spending the time to do the tuning. Spend a whole trip if you have too. You'll thank yourself later, trust me I do.

Speaking of air/fuel mixture screws, I cannot keep mine from backing out. I had to readjust mine about every few hours this weekend. Any ideas on how to get it to hold it's setting? And if I shut the quad off by the key, it will keep running for 5-10 seconds. Is this from running to rich? I am thinking it is.

 

Noone has a clue on this or what?

 

Is this a dynojet kit or mikuni main's?

 

If you have backfireing through the exhaust then you have to much fuel in the exhaust. This means you are to rich. The fuels that we use now are very clean. If you are running race fuel, it will not color the plug like we are use to.

When jetting, I run my quads as rich as I can get them (backfireing and stumbling) and then drop the main jet down one or two size's.

This is only good for 3/4 to wide open throttle. You will still have to jet the bike at idle and 1/4 to 3/4 throttle.

Jeffnrivercity has a good idea, at nighttime, let the bike sit and IDLE for at least 10 mins. If the head pipe glows, it is to lean. But this is only good for Idle.

For everyones info, if the motor is running real rich, the exhaust temps will make the pipe glow, but it will also backfire or stumble to let you know that it is rich.

James

 

Demon:

Mine started to do that keep running thing after I installed my Tach. It also seems to do it when hot and the fan is running.

Seems to me there must be some electric feedback thing that is going on.

Bomber650:

Make sure your are checking your plugs after a heavy load (hard riding). Best thing to do is to shoot the biggest hill around then check the plug.

If you are checking the plug after idle you will not get your answers. The jets only control fuel flow from 25% to 100% throttle so, anything below that and the jet size isn't your issue.

Check out Buttfungus' site and compare your altitude and set-up with those that others are running. Keep in mind the Dynojets are different than the Mikuni jets.

Good luck.