R69 not running right

schrader7032 · Post by **schrader7032** » Tue Dec 04, 2007 4:58 pm

Check the thread titled "Newbie", about 2/3 way down on second page. There was discussion about something similar, about the bike bogging down. Maybe you can get some ideas there.

Do you have in-line fuel filters? Some don't like them because they might be restrictive to flow, but I tend to think not. The one thing they do is allow you to see if there is fuel flowing to the carbs. If the filter, located just before the inlet to the carb, but up far enough for you to see, doesn't look likes it's full of fuel, there might be a problem.

For my money, I'd investiage fuel first, then ignition.

Kurt in S.A.

Bruce Frey · Post by **Bruce Frey** » Wed Dec 05, 2007 3:15 am

Whenever you have a warmed up bike (or car) that stalls and won't restart, immediately check to see if you have good spark.

That is a classic symptom of a failing coil.

Bruce

Bruce Frey · Post by **Bruce Frey** » Wed Dec 05, 2007 3:19 am

I forgot to add that those symptoms also describe a plugged inlet screen on the petcock.

Bruce

schrader7032 · Post by **schrader7032** » Wed Dec 05, 2007 12:25 pm

Whenever you have a warmed up bike (or car) that stalls and won't restart, immediately check to see if you have good spark.

That is a classic symptom of a failing coil.

Bruce

I guess I maybe read too much into the initial post. "It sputtered, lost power and felt like it was starved for fuel. Then, after about 5 minutes, it started running perfectly again." I took that to mean that it ran poorly for 5 minutes and then somehow got better.

I'd agree that a difficult time restarting can be a coil. Unless it's marginal, I would think it would take more than 5 minutes to cool enough to work again. Most people have reported having to wait a significantly longer period of time before the bike can be restarted.

Kurt in S.A.

redavide · Post by **redavide** » Wed Dec 05, 2007 4:52 pm

Schrader, You understood my original message correctly. It didn't stall and it always starts easily. It lost power, sputtered and generally felt like it wasn't getting fuel, but kept running nonetheless, for a period of about five minutes, then suddenly snapped out of it and started to run fine. This happened 3 separate times on a 100 mile trip.

This morning I started it and it fired right up on the first kick. I didn't ride it, but the engine was running rough at idle and started sputtering when I gave it some throttle. I assume that if I take it for a ride, it will probably start running fine at some point like it did the previous 3 times.

Thanks for your advice.

schrader7032 · Post by **schrader7032** » Wed Dec 05, 2007 6:09 pm

Well, we might temporarily rule out the magneto coil. But it's hard to say what the problem might be. Did you try the ticklers this morning??

If it were me, I'd start a process to confirm that all of the basic settings were correct. It's likely not the valve clearances. But confirm the timing, probably with a timing light. It would be interesting to see if the timing was changing between good and rough idle. Nothing to disassembly but just hook up the timing light before you start it. You should probably check to ensure that the safety gap is set correctly on the coil. Make sure you the plug caps are on tightly. Are you using the metal shroud caps? I understand they can leak voltage to the heads, creating a problem. I bought a set of the brown bakelite caps from Vech.

Next you might have to be sure that the floats are indeed floating and that they don't stick open/closed. Next time this happens, try tickling. Also try rapping on the float chamber (where the gas goes in) and see if this might cause the float to become unstuck.

Try to do things methodically so you can move from one to the other. Also, consider which things are the easiest to do and do them first.

Hopefully others will provide their thoughts so you can list all of the possibilities and start checking them off.

Kurt in S.A.

Darryl.Richman · Post by **Darryl.Richman** » Wed Dec 05, 2007 9:06 pm

I would check the fuel bowls for "crud", especially flakes of tank liner.

Allan.Atherton · Post by **Allan.Atherton** » Thu Dec 06, 2007 7:29 am

... It didn't stall and it always starts easily. It lost power, sputtered... but kept running nonetheless, for a period of about five minutes, then suddenly snapped out of it and started to run fine. This happened 3 separate times on a 100 mile trip. This morning I started it and it fired right up on the first kick. I didn't ride it, but the engine was running rough at idle and started sputtering when I gave it some throttle....
Reminds me of when a condenser went bad. If so, the problem will progress -- become more frequent and occur at lower rpms, until the bike will not idle well and then won't start.

I cleaned and replaced everything on my bike, trying to stop the missing, which had progressed to where the bike would barely start or idle. Carb kit, plugs, wires, even the coil. But not the condenser, because everybody said they never go bad. I did not even own a spare condenser. Finally I took the condenser out of another of my bikes, and it cured the problem.

They say that at those instants that the condenser does not work, the spark will jump at the points instead of the plugs, and can be seen there. I had not heard of that at the time.

Darryl.Richman · Post by **Darryl.Richman** » Thu Dec 06, 2007 9:27 am

In my experience, a condensor going bad will begin as a high speed miss. It will progress as Allan says, until it's very hard to start and barely runs.

You can easily tell if your condensor is having problems by running the bike in you darkened garage with the front cover off. Everytime the bike misses or runs rough, you'll see sparks at the points. The condensor's whole purpose in life is to prevent arcing at the points. (Allowing arcing across the points reduces the abruptness of the collapse of the field in the coil and weakens the spark.)

But in my experience, the problem doesn't come and go; once it starts, it just gets worse. Bad running for 5 minutes 3 times in a long ride doesn't sound like a condensor, to me. (I could be wrong -- it wouldn't be the first time! -- and some wag has said that 90% of carburetion problems are electrical.)

OTOH, if the red liner in the tank were flaking off, bits of it will go through the screen over the intake tubes at the petcock and then it will tend to block the flow through the jets, until some event creates enough vacuum to pull it through, usually closing the throttle, which creates a high intake manifold vacuum.

One other thought -- could this be one cylinder not running well? In which case, I would suspect the plugs, plug caps and/or plug wires. If yours are not new, it's not so expensive to replace them.

And, finally, we had a guy here in the SF bay area who was having a rough running problem, hard starting, too. He went through, set valves, timing, adjusted the carbs, and nothing helped. Finally he discovered that one of the little set screws holding a plug wire to the coil had gone missing and the plug wire was just making light contact with the coil terminal.

Good luck!

redavide · Post by **redavide** » Thu Dec 06, 2007 9:59 am

First of all, thanks for all of the useful replies -- I really appreciate it.

This morning, I checked the floats and they seemed OK -- there was some dirt on the bottom of the bowls so I cleaned them out and put a couple of in-line fuel filters in because the inside of the tank isn't in the best condition.

I'll be out of town until Monday, so next week I'm going to take it for a ride and if it still has the problem, I'll take the front cover off, check connections, etc. and see if the points are arcing. The plugs are new, the spark plug wires are new and they have the brown bakelite caps. I'll post my results as they happen . . .

Thanks again.