Stalling at Idle does not restart

[curtie94]

The previous owner swapped the bike to points.

Unless the points are dirty?

I'll file the points and try it again.

[JTGS850GL]

How did you confirm a "partially clogged" pilot jet? My concern is that if the pilot jet it self was clogged, it may indicate other passages within the pilot and needle circuits aren't completely clean either.

[JJ]

I did strip and dip the carbs. I actually have done it twice. Once last summer and then again this winter. Maybe I missed something last time.

Stripping and dipping the carbs isn't good enough. You have to take a fine wire and probe every tiny opening in the carb bodies and assorted jets. Only when they are all clear and clean are you ready for reassembly.

Do it right the first time through and save some heartache and unnecessary time and labor later...

[curtie94]

I could only see a little light through the pilot jet. SO I cleaned it with a wire and I also checked for flow though all the circuits through the carbs, everything else seemed good.

I rode it a bit tonight 35F, it was cold. But I noticed a slight hesitation on take off and when I would come to a stop the revs would hang at 2500-2000rpms for a second then drop back to idle. But I was afraid to let it idle because I though it might stall.

Here is something I noticed, after it stalls if I start it back up with starting fluid it when I try to rev it out the revs only get to about 6-7000 rpms then its starts bouncing around not revving any higher. It seems like a rev limiter which I know I don't have.

I think ill look into the points a bit tomorrow.

Before the bike does stall it will faulted quite a bit. It will be idling at 1200rpms just fine then all of a sudden it will drop to 900rpms, then bounce back to 1200 and be fine then it will happen again then finally stall.

What about a condenser that is getting hot? Could I run a couple of external condensers and see how it runs? Could a bad condenser even act this way?

[tom203]

The previous owner swapped the bike to points.

Unless the points are dirty?

I'll file the points and try it again.

Points? Condensers? The plot thickens! The condensers could be heating up and shorting, causing poor spark till they cool down. Unusual but possible and I'm desperate to blame this on electrical
problem.

[curtie94]

Let me ask one more question.

If I have the key on and the plug wire about a 1/4" from the cylinder head and I manually open the points should I get a spark every time?

[tom203]

Likely. If you put cap back on spark plug and hold plug against engine , yes

[Grimly]

Points are the first thing you should check. We've all got out the habit of it, but it used to be ingrained in us. Points, condenser, plugs and leads. Condensers are notorious for breaking down - especially in the hostile environment of engine heat, and it's surprising they last as long as they do. They rarely get changed, especially back in the day, when a set of OEM points and condenser would set you back a fair whack in your pocket.

[curtie94]

I ordered a set of new points and condensers.

But today I decided to take a heat gun to the condensers and after about 30 seconds the bike started to faulter and it stalled and acted the same way.

So I guess thats my problem.

Im going to go back after the bike out after I let the bike sit for a bit to cool down and see if it will start, if it does ill kill it and heat the condensers and see if it starts after.

[tom203]

It would be nice to have closure to this thread! Even nicer if this snow disappears ASAP - my bike needs to find road and I need 50 degrees F again.

[curtie94]

Sure enough.

The bike fired right up so I stated heating the condensers and it stalled within 20-30 seconds and wouldn't restart.

[curtie94]

All we need is a couple of 50f days and the snow will be gone.

[Grimly]

You've found the fault, then.
A fairly good way of cold-checking the condenser is manually turn the engine over so the first set of points are closed, then switch the ignition on and quickly open the points with the blade of a screwdriver. If the condenser is in good condition, you will barely see a spark across the gap, if it's on the way out, you will see a quite visible spark, and if it's totally goosed, the spark will be very obvious.
Repeat for the other set of points.

[curtie94]

well I just installed the new condenser and points. same thing. still stalling on me.

I checked hot compression again and still the same 130psi. across the board.

I then checked for spark and I noticed I had a weak spark on every Cylinder. I checked with a new plug and I got a nice strong health spark.


Could it be so simple? Could fouled plugs really be the whole problem?

Can a fouled plug spark better when cold?

I guess Ill get new plugs and go form there. Would it help to get a hotter plug? I'm running NGK B8ES's right now

[JTGS850GL]

Should run fine with the B8ES plugs. No reason to run hotter. If the B8ES's aren't working then something else is wrong.