85 350x woes...

[trizmoneypit]

IDK.. I think I'm running awefully rich. the plug is black and oily. its very hard to start,, and when it is running when you let off the gas it backfires. although it doesnt seem to bog when you nail the throttle.

can anyone give me a starting point with is? the whole motor has recently been gone through.

Anyone off hand know the stock jet sizes? I'm running a cobra header with an oem muffler with no baffle. with a uni and airbox lid. if that matters at all


help me out fellas :D

[Mr_RPM]

ill agree with the dark oily plug meaning its running very rich, but it popping when u let off the gas is normally a sighn of running lean. first off get a new sparkplug, see what that does. you may have a partially fouled plug or a bad gap, either way just replace it, its cheap. after getting some time on the new plug (maybe an hour of riding, at least getting it fully warmed up) take the plug and look at it. if its black again then u know its running rich and it wasent just a bad plug, then your gonna want to get more air in or use smaller jets (try to get more air in, that way its faster =]) if its light in color then u probably have an air leak somewhere (explaining the back firing)it may be an exhaust leak or intake boot leak, look around.
change the plug and go from there, because a fouled plug might not be an accurate tool to read if your rich or lean.

[trizmoneypit]

Dumb question here but you think running it without an airbox lid would help? I hate messing with carbs man! :lol:

it seemed to run and start fine in the warmer months. now that's its cold I gotta get towed to start it?!

[harryredtrike]

if its only slightly rich that would work since the exhaust is open.double check all your carb settings,return to stock if off.manual on this site.

[Mr_RPM]

it runs fine when warm, but not when cold, i would say your running lean, in the colder months anyway. and yes taking the airbox lid off does make a difference, sometimes makes a big difference, try it. if im right and your lean then it will make it worse (maybe that black plug is just from fouling and not being rich), if it makes it better then your rich

every machine runs leaner in the cold because the cold air is more dense. so if u were running rich, the cold would make it run better not worse.
so get that new plug and see if it fixes everything all together, i predict it will help a lot if not fix all of it. then let me know and we will go from there

[trizmoneypit]

I just went and got a few jets. one size bigger on the main (140) and a 130. there was I 138 in there. (not sure if that is stock or not)

I'll get the new plug in and try it with the airbox with the holes. does that sound about right?

which way deoes that air srew turn. I was always under the assumption you turn it one way while its running until it almost stalls. thei n the opposite direction until it almost stalls. then turn it back to the position bytween those two points.

what baffles me is this thing has always started on the first or second kick. even up at raffas ice races sittin outside overnight frozen solid????

any feedback or suggestions are welcome, and thanks again guys!

chris

[Vealmonkey]

If the settings on the carb or your timing is bad, then running without an airbox won't help. A new plug will be a step in the right direction. Also I won't take an hour of riding, 10 or 15 minutes should be good. Remember though you have a high and low speed fuel circiut on your trike. You could be rich on one circuit and lean on the other. The backfiring could be a totally different problem than the black on the plug. Before you dive in on the carb, you may want to make sure you static time your engine and adjust your valves. Run the trike for a few minutes and see if you still have the backfiring problem, if the backfiring goes away, then that was the timing, if not, then you have another problem. More than likely air sneaking in somewhere. I would guess around your exhaust pipe. You may want to try some new exhaust gaskets, but you could be getting air back in around where your header and muffler go together. There is a cylindrical gasket that goes in the stock exhaust where they attach. If you have an aftermarket exhaust, then there really aren't any gaskets that I know of in those kits, but I could be wrong. I know DG pipes are notorious for backfiring and I couldn't cure it on my old 200x. A high temperature sealant around where the header and muffler join may help. As for the black sparkplug, I think it's a seperate issue. And there really no way to cure it other than messing with the carb. You will have to make sure you do have a clean air filter though, that will help way more than not running an airbox lid. Not running an airbox lid will cause your filter to get dirtier way quicker than it normally would and it could make the carb issue way worse very quickly. On your carb,

[Mr_RPM]

dont drill holes in your airbox lid before trying it with it off, take it off completely and try it, because thats reverse able and drilling holes is permanent. and yeah like vealmonkey said i think the black plug is a seperate issue, but prolly the reason why it wont start easily. with a new plug u should find it starting like before. as of right now i wouldent play with the jets till u get that new plug and see what color it turns to be