I put a new exhaust on my wolverine. It runs great but when I come down a hill or slow down without braking it backfires, is this normal or is something messed up? I also changed the jetting from 141mikuni to DJ147, does this have any effect on it either? Like I said it runs good, doesnt bog down or skip at full throttle, is it alright? I also had to adjust the idle speed lower, it ran fine for about an hour no backfire then started doing it.

 

Most any quad with an after market pipe will back fire when closing the throttle, especially going down hill. It can occur when the jeting is spot on, like mine. Unfortunately it can also occur when the air/fuel mix is lean. To know for sure requires a test ride with a new plug and a plug read.As for the sizes in jet kits...altho they use the same numbers as Mikunis, the actual sizes are proprietary sizes and not interchangable with mikuni..just one of the problems with jet kits [img]i/expressions/face-icon-small-disgusted.gif[/img][img]i/expressions/face-icon-small-frown.gif[/img][img]i/expressions/face-icon-small-confused.gif[/img]

 

Thanks for the info!

 

I would say the idle circuit is lean. First go to the air-fuel mixture screw which is on the bottom of the carb kinda towards the engine. Start by turning it in all the way -then back it out 2-1/2 turns,this is a good starting point for a Wolverine with the k&n and pipe. Take for a ride long enough to get it hot to see if it backfires. If it does then turn the screw another 1/4 turn out and try again. If you get to the point when you are three turns out and still backfires then you will have to change the pilot jet from the stock 42.5 to a 45 pilot. Also make sure you have no exhaust leaks-make sure head pipe bolts are snug and so on. What kind of exhaust did you get?

 

I got a team Alba pipe. I'm going to try the mixture screw. The pilot jet is inside the carb right? I have to take the lid off and diaphram out, correct?

 

That's right the pilot jet is in the carb. Loosen the two band clamps that hold the carb,the one holds it to the air box tube the other one is towards the engine intake. Then just turn the carb until the bottom is facing out towards you (this is also an easy way to get at the mixture screw)then take off the bottom of the carb which has 4 small phillips head screws -make sure to use a screw driver that fits correctly as these screws are easy to strip. You will see the main jet and the diaphram. Take out diaphram or float and you should see the pilot jet-which is kinda long and thin.Also before you take off the bottom of the carb drain the float bowl. I'm gonna bet that with the mods you have the mixture screw is gonna fix your problem. No matter what pipe you have it shouldn't backfire.
2001 Wolverine -too many mods
checkout MY SITE
too many mods

 

Thanks for the help I'll try that asap. You got some nice pics on your site. I ride with 2 polaris a 700 and 500 they dwarf mine but I have went in every thing they have. I do get stuck alot more mostly because of lower ground clearance but we have fun.

 

slowride1,
something that could be making you backfire but probably isn't the problem would be that your new exhaust isn't sealed correctly to the header and is leaking. It happened to a couple of my friends and sfter they fixed it and got it sealed correctly the pipe stopped backfiring.

Patrick

 

Hot_shoe.......why not try a Dyno-jet kit in your Raptor? With your nice ride, whats another $60.....if you don't like it, sell it and re-coupe some lost cash. I too used too feel the same way about jet kits. BTW, the prescribed DJ kit jetting was'nt correct......very few are gonna need exactly what is prescribed. JMI.
Slowride1.....as mentioned, Idle circuit or loose / bad fitting pipe.

 

I got it figured out. I checked all the bolts, made sure no leaks. Then I turned the air-fuel screw in and backed it out 3 turns. Still backfires, so I got pi$$ed and started drinking, went to wash it and when I went to start it, it wouldnt, I got it started knocked real bad, ie. water in the engine, took the headpipe off, and the flange wasnt on right. Good call on those who said it was a leak, it was so small of one I couldnt feel the air. No more backfire now, runs even better since I turned that screw out too. THANKS