# backfire after installing snorkel



## BigIzzy (May 24, 2009)

Ok so I made up some snorkels for my 650i using the how to, which was incredibly helpful, but now I'm having trouble keepin my engine runnin smooth. I use it for muddin as well as goin to and from work (live/work in the country) and have ran too work with it three times now, first two runs I had the topper for the engine intake turned back at me and it felt like I couldn't get everything out of the engine so I pointed it forward and now am gettin backfires on throttle down from full open. Anyone have any tips?


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## 1bigforeman (Jun 23, 2009)

If it's running better when you turn the snorkels to the front then you are running rich and the extra air is making it run better. Did you use the 3 inch rubber 90 off the airbox or the 2 inch? If you used the 2 then you'll probably have to rejet. If you used the 3 then it will be much closer and may not have to. To get it very close though, chances are you will have to do a little adjusting to the carbs. In a nutshell, idle is controlled by the mixture screw, midrange is controlled by the needle, and top end is controlled by the main jet. That will help on what you need to change to get it running right. I'd start with the 3 inch 90 first if you haven't already.


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## BigIzzy (May 24, 2009)

I ran a 3 inch too 2 inch rubbber off of the air box with some triming and extra clamping would that be enough too restrict the flow considering the 3 inch elbow went down too 2 inch pipe anyways?


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## Polaris425 (Dec 16, 2004)

try removing the screen out from under your airfilter


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## Bootlegger (Dec 18, 2008)

If you need any help jetting it just PM me.....
Instead of trying to buy factory jets...the best and easiest way is a Dynojet kit and they are not expensive either.

1/8-1/4 is your Pilot Jet
1/4-3/4 is your Needles
3/4-WOT is your main jets

Your air fuel screw is your idle and you can adjust and fine tune your up to 1/8 throttle with it. but if you ever have to go 3 turns out or more....don't! Just go up one pilot jet size.


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## Masher (Jan 16, 2009)

He's not rich of course but instead of taping the exhaust snork for a lean condition taping the screen or a cardboard cutout on top of the screen would probably be good to richen it back up. Not applying to this thread but it was in my head and I spouted it here.


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## Bootlegger (Dec 18, 2008)

If it was mine I would just jet it and be done with it. It always seems easier to do it that way than trying to get around it...lol


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## Masher (Jan 16, 2009)

x2^^^


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## BigIzzy (May 24, 2009)

How difficult is it too jet? I've always been nervous around a carb cause I've run into problems before with different engines. What I'm tryin too figure out is why when the topper is pointed back no backfire but can't hit full speed but when its forward full speed but backfire is it cause the air is being forced in?


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## BigIzzy (May 24, 2009)

Also how expensive is a jet kit?


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## hondarecoveryman (Feb 28, 2009)

The reason it back fires when the snork is facing the front is because you are forcing it to be too lean(ram air) If you redo the air intake with a 3'' 90 you will get enough air to prevent rejetting ,because you would need to jet down as it is now. These V-twins have to have just the right amount of air I had to remove the rubber 2'' 90 off the intake tip and put a standard 90 to get mine to run right and not need jetting....Just my thoughts


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## Bootlegger (Dec 18, 2008)

Jet kit is about $55 only get a Dynojet


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