Carb Issues?

[ligrani17]

Hey everyone. I have a 99 Banshee that is running like crap. I rebuilt the motor on it last summer, but it isn't running as well as it used to. The biggest power loss that i feel is at the low end, but i can tell the top end has lost some git up too. and when you pin the throttle it takes forever to hit the power band (and it doesn't kick you back the way it used to) I'm thinking it might be a carb issue. I went through the carbs last summer and everything is clean, but it might need to be re-jetted. So I want to see how everyone else has their carbs set up and/or what you recommend for mine. I live in Denver (5280 elevation) but I typically ride at elevations over 6000. Motor is stock with the exception of a cool head (not sure which domes are in it) and T5 pipes and I run 32:1 fuel ratio. I did a compression test on both cylinders. (160psi and 161psi). So my question is what do you guys recommend as far as jet size/ and needle placement? or do you think it could be a totally different issue. Thanks in advance everyone.

 

J-rod

[2002shee]

Did this start all of a sudden or since the rebuild? Did it run ok at one point with the current jetting? Is the gas fresh and have you tried new plugs?

[rdzbangshee]

Hey everyone. I have a 99 Banshee that is running like crap. I rebuilt the motor on it last summer, but it isn't running as well as it used to. The biggest power loss that i feel is at the low end, but i can tell the top end has lost some git up too. and when you pin the throttle it takes forever to hit the power band (and it doesn't kick you back the way it used to) I'm thinking it might be a carb issue. I went through the carbs last summer and everything is clean, but it might need to be re-jetted. So I want to see how everyone else has their carbs set up and/or what you recommend for mine. I live in Denver (5280 elevation) but I typically ride at elevations over 6000. Motor is stock with the exception of a cool head (not sure which domes are in it) and T5 pipes and I run 32:1 fuel ratio. I did a compression test on both cylinders. (160psi and 161psi). So my question is what do you guys recommend as far as jet size/ and needle placement? or do you think it could be a totally different issue. Thanks in advance everyone.

 

J-rod

if you have the tommy jet kit with needles you could move the needles & clips positions to adjust the fuel mixture you could be running to rich on fuel.I would try the fourth clip with 270 main jet and go from there.and a adjustable timing plate helps allot.

[ligrani17]

Did this start all of a sudden or since the rebuild? Did it run ok at one point with the current jetting? Is the gas fresh and have you tried new plugs?

 

 

It only went on 1 trip after the rebuild and it's sat ever since. So yes it started after the rebuild. Once i realized it wasnt running correctly I went through the carbs and changed some things to try to fix it quickly before the trip, I'm pretty sure I moved the needle position thinking it was running too rich. but it still ran bad. My initial thought was I needed to rebuild the top end, I assumed my compression was bad. Thats why it sat for so long. I finally got a compression tester recently and am now discovering that compression isnt the issue. Gas is fresh, and I went threw a few sets of plugs hoping that it would be something stupid and simple. But it feels like its getting flooded with gas.

[WINDYCITYJOHN400]

It only went on 1 trip after the rebuild and it's sat ever since. So yes it started after the rebuild. Once i realized it wasnt running correctly I went through the carbs and changed some things to try to fix it quickly before the trip, I'm pretty sure I moved the needle position thinking it was running too rich. but it still ran bad. My initial thought was I needed to rebuild the top end, I assumed my compression was bad. Thats why it sat for so long. I finally got a compression tester recently and am now discovering that compression isnt the issue. Gas is fresh, and I went threw a few sets of plugs hoping that it would be something stupid and simple. But it feels like its getting flooded with gas.

Go thru the carbs a second time.....fuel needle might be leaking when it's running. Also use the Brake cleaner and blast those jets good and make sure the fuel needle seat it good and clean..

[ligrani17]

Go thru the carbs a second time.....fuel needle might be leaking when it's running. Also use the Brake cleaner and blast those jets good and make sure the fuel needle seat it good and clean..

 

 

First off... Thanks for everyones input. After reading what everyone had said, I knew that my carbs and jets were incredibly clean from the last time I went through them. So I decided to do a little research and find out what Toomey recommends for my carb set up. And while reading there instructions I came across a section that made the bright light go off in my head. Fact of the matter is... I'm an idiot... The instructions specifically say to work on one carb at a time so that you don't mix up your slides in your carbs. And as soon as I pulled the seat off I could tell that some wires were twisted. and I had my slides in backwards. The slides in the carbs have a half moon shape cut out of the bottom. This side must be facing your air box. Otherwise it will run like the choke is pulled out. This was the problem with mine. I pulled one carb out just to double check the needle and see what jets were in it. Needle was on the 4th slot (Like it is suppose to be) and it had a 280 jet (which is what they recommend for sea level so that will have to change eventually) But I swapped the slides back to normal. It fired up on the first kick. and ran like crazy. I even caught myself off guard by accidentally pulling the front end off the ground when I punched it in second gear.

Thanks again for everyones input. It was all your advise that got my brain cranking in the right direction.

 

J-rod