Having heck of a time with my spitfire

[Steven J]

I've pretty much ruled out carb troubles on mine,Dennis Kirk has coils,but not showing CDI boxes. Where can I get one?

[just_some_dude]

I just purchased one from here: http://www.psep.biz/store/john_deere_sn ... _boxes.htm

[kreechur]

I got mine from there also...

just_some_dude - to answer your question from before, There was not a whole lot i did other than check the coils. It was pretty much a gamble for me...

[just_some_dude]

It seemed just about the cheapest place I could find it.

[just_some_dude]

Okay, here's an update to my situation. Hopefully you can still help me out.

I'll just quickly go over the changes I've made overall. I've cleaned the carbs, made the adjustments according to the service manual, changed the spark plugs. I recently, just put in a new CDI, tightened the head bolts again, and replaced the belt.

The sled is running significantly better, but it's still missing it's spark or snap. If I hit the accelerator it takes a bit to get moving and it still can't hit high speeds. I'm still having an issue with the engine cutting out at full throttle. It's better than before and I have more throttle before it cuts out.

I also can start the sled on first pull.

I'm just trying to figure out what I'm missing here... I did accidently put 87 gas in, but I don't think it'd have that drastic of a performance loss. I wouldn't know for sure, though. Another possibility is too much oil in the mix. I don't know if that'd make a drastic performance loss.

Is there something I'm missing?

[kreechur]

Is the exhaust clear and no obstructions? Also which carb was it, was it the round slide or the Butterfly?

[just_some_dude]

Round slide. I guess it's possible for the exhaust to be obstructed, but it doesn't seem to have any issues getting smoke out of it. What's the best way to check and see if the exhaust is obstructed? Do I have to take it apart?

[just_some_dude]

I took the exhaust off and cleaned it a little bit. I don't know if it's going to make any difference. I guess we'll find out later today.

If anyone else has some suggestions, I'm open.

Thanks.

[just_some_dude]

I was just reading some stuff online and I was just thinking about it. I don't know how accurate this is, but this is what I read (and it may have nothing to do with this): "If you hear the engine "pinging", a noise like shaking marbles inside of a tin can, that as well as backfiring is a sign of a too lean mixture and you need bigger main jets. If the bike "blubbers", doesn't accellerate as crisply as before and soots up the exhaust, the main jet is too large and a smaller one needs to be installed."

When I start the engine it "pings". When I hit the throttle it cuts out, maybe too rich?

I'm just confused. I just can't figure out the problem.

Could this be something stupid like replacing the fuel, or fuel filter? Changing the air/fuel mix?

I'm sitting at work, not working at all because all I can think about is fixing this snowmobile

[milkman]

Fuel filter?

[murph6090]

I'd say fuel filter to i replaced the filter on mine because it would cut out at high rpms like yours.

[daisydukers]

How's the compression?

[just_some_dude]

Bad. I believe the heads are warped. Also, one of them is beat up from me breaking a stud. Unfortunately, I learned a lot from the sled, just part of the sled suffered from my lack of experience. Parting it out, though!