OK I just got my pipe changed the Main jet, and the quad will Idle but I can't rev the motor! It was around 35º outside but I let the quad warm up for the same amount of time I do before I got the pipe. Do you think its still to cold? Its running WAY RICH!!! I don't think it is because of changing the main jet because it only controls 3/4 - full throttle. PLEASE HELP ME

ALSO a few people told me to go up 4 jet sizes, do they mean 4 available sizes 125 to a 132 or
125 - 129???? THANKS !!!


1987 Honda 250X, K&N, AirBox Vents, DG RCM exhaust

 

I have an LT500, not a 250R so things may be different, but I only changed my jets for the richer two (2) availible sizes. On mine I went from a 220 main jet to a 240. There was a 230 available also. I think when it gets warmer I will put the 230 in. Probably only 2 jet sizes richer is fine. Mine seems perfect.

 

Not sure what you really did on your rejetting, but the rule of thumb with adding most pipes is to rejet two sizes fatter than stock and test. Not being familiar with 250r's I have no clue what the actual sizes involved would be. If you have gone more than 2 sizes fatter, that's probably the problem. Your are correct on the matter of the main jet..it wouldn't affect your idle, so that is your clue, If you know what the stock size is , then go two full sizes, ignoring the 1/2 sizes such as point 5 and so on. Try that & see what happens at 3/4 to full rpms. It may be that you'll have to drop down one more size to make it run right on top, depending on your particular pipe.

 

My 250R always ran a little on the rich side, so when I changed my pipe, I didn't rejet.

A couple of friends kept nagging me to change, but, I told them it was already rich and could use to be leaned out, they kept nagging me, but the pipe has been on for 2 years now with no trouble.

Anyway, I am still running stock jetting and the thing runs amazingly well, the pipe made a huge difference.

Moral: Blanket jetting statements are guidelines, not absolutes, it varies by individual bike. Put your stock jets back in, try it out, read the plug, jet (one step at a time) from there.

 

I aggree with Gabe...if it ain't broke, don't fix it! The rule of thumb is to only change one item at a time whether it is a pipe or carburator part. Put the old jet back in and READ YOUR PLUG.

 

Pull the air box lid off and see if it runs a little better. If so you're jetted too rich.

 

You really shouldn't have to change the jetting with a new pipe at all, and here's why. An aftermarket pipe actually "forces" more of the unburnt fuel/air mixture back into the cylinder to get burned. That means that you actually run richer with a new pipe. I am almost positive that if you put your stock jetting back in there your problems would be over. If you take off the airbox lid or get a different air filter then I would rejet. If with the stock jets it is running lean, change the needle position first. Then change the main jet.

 

I dont know if you guys noticed or not, but isnt _250R_ talking about his 250X? i think so, just check out his signature. just thought i would let you know. bye

 

Hey Homie,
Sounds like your slide isn't workin,are you sure you didn't get a little curious and pop the top off your carb? Check to see if it is moving or if you're using a vacuum style carb that the blatter is sealed tightly.

 

I am talking about my 250X not my 250R. Thanks for the help though. The reason it didn't work was because the jet was marked wrong!! It said 132 but it was really a 113. I took it back to the dealer and they ran a flow check on it and it was a 113 so I got a NEW 132 and now it runs fine... ALSO________
V
The DG RCM pipe I got is great!!! Everyone I've asked about the pipe said it sux, but it performs well and has a nice sound. Its very tough and has a nice look!!

-----1989 Fourtrax 250R - 330 kit, FMF Fatty, FMF Power Core IV, K&N w/outerwear,Holeshot tires F/R.--------

-----1987 Fourtrax 250X - Stock bore, DG RCM exhaust, K&N w/outerwear,Airbox Vents Puresport Bandits F/R------