Crackership

Hi All,

I've been stalking the forum for a while now, but I've got my first issue I can't solve with search. Hopefully someone can help me out here, cause I'm stumped.

Little background on the bike: It's a '98 with ~17k miles on it. Staintune exhaust and, as far as I can tell, no other mods. I've had it for about 2 months now, and it really hasn't given me any problems until recently.

Here's what happens:

On a warm day - Bike runs fine, kinda sluggish when it cold and will miss occasionally when cold, but once it warms up, it runs great. It idles a bit high, but I understand from reading the forum that was likely done by the PO to keep it from occasionally dying at idle.

On a cooler day (like 65F or less) - The temp gauge stays around the 1/4 mark and the bike has a less sharp throttle response, but it's ok.

On a cooler day with rain - Any time I'm moving faster than about 35mph, the temp gauge dives to about the 1/4 mark and the bike is lethargic, highway speeds for any length of time bury the needle in the cold and the bike runs awful. Earlier this week, it dropped the rear cylinder after about 15mins on the highway and didn't pick it back up again until I shut it off and re-started it, but it started fine and sounded fine immediately after starting it.

This is a weird problem, so I've just started with checking basic stuff - I've checked the plugs - they seem fine, checked the air filter - seems fine, checked the plug wires - they seem fine... I ordered a replacement air filter and plugs anyway, but I really don't think either of those is the problem.

Any ideas? Anyone seen this happen before?


Thanks guys

Crackership

One additional thing I noticed. The little foam filter things in the air box (sorta triangular shaped, one at the front left the other at the right rear of the box) that look like they go to the sides of the carbs look pretty rough - rotted out. What are those? Do those have much or any effect on running? Also, what are they called? I can't seem to find them online.

CruxGNZ

Welcome Cracker!
Regarding those little triangular pieces of foam inside your airbox, you can make your own. I went to JoAnne Fabrics and picked up a small chunk of foam (I would assume Ace Hardware, Home Depot, and Menards would also have foam), cut it to shape and thickness and then installed them. Very easy to do.

Now, your running problem is more interesting. Sounds like the thermostat is stuck open and not letting the bike get up to the correct temperature.

It also sounds like you need to pull the carbs and clean them. Once the carbs are cleaned and installed, you will want to sync them.
EDIT: Maybe sync the carbs first, since this is easier than pulling them. Then, if you're still having issues, pull the carbs and clean them.

If this problem persists, I would look at your coils and wires. If you're spending money on new parts, may as well upgrade, right? Look into fitting stick coils. It's very easy to do and if you do it right, will cost you nothing* except your time.

*Usually stick coils come in fours (look on eBay for deals). We only need two for our bikes. Make sure you get the harness. Keep two and sell the other two. You can usually sell the other two on this forum for what you paid for the four

CrankenFine

thermostat

Crackership

Thanks for all the info!

I've got years of wrenching experience, but I've managed to completely avoid carbs until now, so syncing the carbs sounds daunting. Is there a good resource for how to and what I need? I've searched the internet quite a bit and it seems that I need a rather expensive gauge setup thingy. Is that so? Also, I don't know what to do with it once I've got it anyway. I'd really prefer to learn how to do this all myself as opposed to just paying a man to make my problem go away.

Also, with the Staintune exhaust, is aftermarket jetting required/recommended or are the stock jets ok? I seem to find conflicting information in that regard.

Thanks again!

insulinboy