Running on 3 cylinders

[the_journeyman]

Ok, it's me again...

So, after reassembling the bodywork on my bike, I went out for a shakedown run. Everything felt fine. I was extremely low on fuel, so with the bike seemed to not run right, I thought it was because it was fuel starved.

Filled up, took off, grabbed some throttle, same lack luster response. Thinking maybe it just needed a minute to get the carbs filled back up with gas I rode on, maybe 3 or 4 miles. Problem still there, so I checked the header. Sure enough, #4 was only warm, not even close to hot.

Two or three nights ago, I took it for a ride before putting all the bodywork on and it was fine. Kinda makes the think it's not a fuel problem, else I would have noticed then since I hadn't touch the carbs since before that ride.

Hooked a multimeter to the #4 plug wire & got readings, just it was changing so fast, I couldn't actually read the numbers coming up. It appears there is fire coming down the plug wire.

#1 appears to be just fine too, so that should eliminate the coil.

After a 10 minute ride, I could put my bare hand on the #4 header pipe. Water sizzled on the other three.

Where should I check, what should I check & how should I check it?

Thanks!

JM

[Nessism]

Good plugs? Spark plug caps sometimes crap out as well. NGK's are about $5 each and work well.

[rockford]

Yep!

I've experienced the same problem a couple of times. Each and every time it was a carburator problem; nothing else. I tried every single thing I could think of to fix it but ended up taking off the carbs and giving them a thorough cleaning every time.....which fixed it every time. Maybe, there's a better answer; I hope so.

[the_journeyman]

I do hope so, I JUST re-worked the carbs. I'll pick up replacement plugs to be sure. I have a hard time believing that the carbs altered themselves 48 or so hours AFTER the bike was running fine and I had touched nothing but bodywork ~

JM

[chef1366]

Switch the plug caps around and see if the trouble follows.

[the_journeyman]

Will do Chef, gotta put tires on the cage tomorrow, so I'll be doing plenty of garage work ~

JM

[Captainkirk]

Congratulations...you now have what Triumph referes to as a "Speed Triple"......:-D
But seriously, folks....sounds like a carb issue to me as well. I've seen the symptoms before. Check the pilot jet on that carb, as well as the float needle (might be stuck in the housing).

[49er]

Congratulations...you now have what Triumph referes to as a "Speed Triple"......:-D
But seriously, folks....sounds like a carb issue to me as well. I've seen the symptoms before. Check the pilot jet on that carb, as well as the float needle (might be stuck in the housing).

I lay my money on #4 carb as well.
You may have a partially blocked pilot jet. Sometimes after a backfire, the crap will dislodge and the engine will run ok. Once the bike sits again, the obstruction finds it's way back across the passage.
Bite the bullet and re-clean that carb.

[chef1366]

I lay my money on #4 carb as well.
You may have a partially blocked pilot jet. Sometimes after a backfire, the crap will dislodge and the engine will run ok. Once the bike sits again, the obstruction finds it's way back across the passage.
Bite the bullet and re-clean that carb.

This guy knows his sh!t!!
Respect bro! :-D

[the_journeyman]

Ok, in looking at the carb (not disassembled yet) there is gas in the float bowl, I'll give an update in a bit, going to switch the plugs around just to be sure.

On a side note, the carb does seem suspect because the plug wasn't wet & reeking of gas when I removed it. That sounds like fuel never got there in the 1st place ~

JM

[the_journeyman]

Ok, I swapped the #1 & #4 plugs... the results? My GS is possessed.

It only ran on #2 & #3 so maybe the plugs are suspect, but possibly not the only problem. I'll replace those today and see what happens.

Since the problem spread, there's a problem with #4 plug. However, after switching the plugs back to the original location, the problem was STILL in #4. When I pulled the plugs after swapping them, they both were wet with fuel.

I'll check back in after I replace the plugs ~

JM

[the_journeyman]

New plugs, still cold on #4.

However, after draining the #4 bowl, I pulled it off with the carbs still in place & hooked up to the tank. Float valve is working properly. Popped the rubber plug off of the pilot jet, got a little fuel from there too. Reassembled #4, started it and everything seems to be working.

I'll just not be able to understand why ~

JM

[chef1366]

You cleared out some gunk that was in your pilot ciruit. I hope it doesn't return.