I have a 92 1200 sportser w/10,000 mile. It has dealer installed straight pipes. I got this bike last year from friend. It sat for a year. I ran 3 or 4 tanks of high test through it already. It runs better from when I got it, but it has a slight backfire through the intake. It has 2 new plugs and wires from when he got it. I pulled the plugs and the front cylinder is white and the rear one is brownish. I think the front one is running lean. Does the shop manual say what size jetts are suppossed to be in there? The dealer was supposed to of rejetted the carb. The dealer I was told are a bunch of hacks.
Where is a good place to get a jet kit or just jets? I've going to run sea foam on my next tank.
Thanks for the help,
Mike

 

the seafoam will probably help. The brown is what you're looking for. Your slow jet is probably a little blocked off if it sat for a year. I would run at least 92 ALWAYS in your bike. Just keep in mind that the last rpm you were running, is what you're seeing on your plugs. It was probably idle, if the seafoam doesn't fix it, there's an enricher screw, probably on the bottom of the carb, you can turn it a half turn and see if that helps.

 

You can get the jets from the stealer for about $6-$8 each... I think the stock jet varries from year to year but, my 04' was a 42 pilot/slow jet and I've read that you only want to go up 1 size at a time.

Worse comes to worse you can take off the carb, the jets are stamped in the top as to what size they are. check out www.harley-preformance.com they have a great article on tunning and jetting your stock cv carb.

Hope that gets you pointed in the right direction.

Jason

 

If the bike sat for a year without having stabilizer added to the fuel then your best bet is to removed the carb, tear it down and give it a good cleaning. Being it's around 17 years old, it's likely due for a rebuild anyway. And, get a new set of pugs.

 

Thanks guys!! I'll get into the carb and see what it looks like. I'll also get a set of plugs while I'm at it.
Mike

 

Your real problem is those piece of crap straight pipes, there's no real good way to get a bike to run on the street with drag pipes.
Get rid of the drag pipes and 3/4 of your probelm will be gone.
Seafoam isn't going to redesign those drag pipes!!!

 

I just fixed up a 2002 that had sat for about 5 years. I gave the carb a gentle clean while still on the bike and it was running but I was having similar symptoms to yours. Once I removed the carb and gave it a really good clean I was able to fix the problem.

 

Info here:: Carb Tuning

 

Phat and Blcfalc,
Thanks for the links. I guess if I get into the carb and find the enrichment plug still there the dealer probably never did anything with the carb.

jag,
I would like to get rid of the pipes but haven't any luck finding a different set. This is my first bike and it is just a stepping stone to something bigger. I really don't want to put too much money into it but I want it to run good. I think I'm going toput baffels in the pipes anyway.

 

I don't believe any dealer will drill out the mixture screw. EPA will be on their butt in a heartbeat. They don't want you messing with it. Same thing is happening with all small gas engines. The dealer may have changed jets but that's about it. Don't blame them, blame the government