95 softial. I've owned her for 4 years and very "occassionally" she'll run rough and sputter after normal run-up. In these rare instances, the bike has always smoothed out and run perfect after maybe 5 miles or so. But not last evening...it never did. Strange thing is that it hadn't had one hiccup this whole season. And it was an immediate change in performance, from perfect all year and the evening before, to super rough the next day ( wouldn't go faster than 30mph). Even after about 12 miles, she never ran properly for me. So I hobbled her over to the store and decided to give Seafoam a shot. Seems I've read about that somewhere. Anyways, no success. I do know I need a new petcock, my reserve has become less and less ( ran out of fuel last month after only 4 miles of reserve). So I'm wondering if there's sediment that may have seeped into system or carb, or maybe moisture in fuel ( fairly recent fill-up). My worst fear is major carb repair. Do they become faulty abruptly like this, or is it usually a gradual consistent decline? Any input I would greatly appreciate. Can I return a half-used can of Seafoam??

 

If you know you need a new petcock, I'd start there and see if it is clogging up the system somehow.

Could be an intake leak as the seals get old after a while. Several different methods of testing, but most require the spraying of another combustible aerosol around the seal area on the intake and noting the change in idle, etc.

Griz

 

Agree with IB, remove the petcock, clean and flush the tank if necessary, I'd also replace the fuel line and clean the carb bowl.

 

As I recall, '95 was the first year of the vacuum petcock, and they are a known failure point. I'd replace the petcock with a manual petcock (block off the vacuum port at the manifold, of course). If you're starving out on reserve, I'm guessing there may be major sediment build up on the fuel strainer and in the tanks.

A vacuum leak in the petcock or vacuum line could account for the motor being starved for fuel. This would be a good time to go over the fuel system and clean the fuel strainer at the petcock (or replace, as mentioned). Also remove and clean the float bowl and carb jets. A new fuel line (and crossover line) wouldn't hurt if you don't know when they were replaced. Cleaning out the fuel tanks would be advisable if there's a lot of junk in the petcock strainer and float bowl.


(edit), I see Sir Graham has posted simultaneously with me.

 

When I had it in the shop about a year and half ago, the float bowl had been checked and looked good. I have minimal mechanic skills, but have been successful repairing several things after a little research. So my confidence is growing. How do I flush the tank? Removing and installing new petcock looks simple. But need some guidance on how to not get fuel everywhere ( tank is pretty full). And also confused about the reply about vacuum line....I need to do something besides just removing it? I took her out for a test run after posting today and it's running the same way.....crappy. But it does sound like the fuel flow may be restricted. Starting with replacing petcock sounds like a good starting point. The weather here in NW Ohio is primo now for riding....this sucks.

 

Easiest way to drain the tank is to

(a) shut off the petcock

(b) disconnect the fuel line from the carby (be careful...from the factory the inlet nipple on the carb is plastic, and they tend to break easily. If your's does break, no biggie. It can be replaced.)

(c) pull the line back through to the left hand side of the bike

(d) turn the petcock on and drain the tank into a suitable size gas can. Not a lot of people have five gallon cans sitting around. Holler at your neighbors and have them bring their gas cans over for a free fill-up. Be prepared to wait a while. It takes a fair amount of time to drain a full tank.

If you have the vacuum petcock on there, I'm not sure how to get it to flow without putting vacuum on the control hose. Hopefully someone chimes in with that info.

I agree with the above advice regarding getting the new petcock installed and seeing how things stand from there.

If you find that your problems are still there after the new petcock is on, don't fret. Cleaning out the carb is a bit of a fiddle, but nothing you can't handle!

Oh, and while you are at this, you may as well head down to the hardware store and get a new piece of fuel hose. Can't hurt. Get a couple of small hose clamps while you are there, in case your bike has the crimp kind now that you have to cut off.

 

Before you get too far in the weeds on fuel delivery, lets have a look at the plugs and make sure she's firing on both. Not wanting to go over 30 and fixing itself repeatedly (until it didn't) Could well be a spark issue. I can tell you from experience that they run just that way on one lung.

 

Alright, so I pulled the front plug...looks good. Pulled the rear....completely fouled. What should be my next step? Or should I just put in a new plug?

 

That's progress. Check compression, even if you just put your thumb over the hole and crank it over. Should blow your thumb off with some force. I'm thinking you have compression, but a quick check rules it out completely. If good and you have a stock dual fire system, start with new plugs. If it still misses, swap wires around and see if the miss moves. You're trying to isolate if it's a wire or the coil.

Dual fire you can swap one end of the wire only, or swap the complete wire front to rear to help isolate. If it's single fire, you have to swap both ends at once (complete wire from cylinder to cylinder). A single fire system can also drop a cylinder via the ECM, so check those leads with a VOM as well.

It sounds worse than it is. You'll track it down in 15 minutes.

 

Dang Owtlaw, read your post after I put in new plugs. In any event, I knew I was back in business as soon as I fired her up. She runs beautiful! I checked my log, and it's been about 15k miles since the plugs were changed. Usually I'm up on stuff ( especially oil changes), but I guess I've slipped a little on overall maintenance. Any thoughts on whether or not I might have an issue somewhere? Like I said, I'm no wrench. I was just gonna keep an eye on her. How often should plugs be changed? Appreciate everyone's input, didn't even think to pull a dang plug and start simple.