[panard]

My 350 was running fine but suddenly over night it was not. It runs fine until it warms up good then it starts cropping out and will barely run. Could this be caused by coils, rectifier or another electrical problem? It has old compression, points are correct and plugs are new. Any ideas? Thanks. Jay

 

[76TWIN]

Could be many things but lets start with the basics first.

1. What do you mean by "old compression"?
2. Did you check your ignition timing? Does it advance properly?
3. Did you check to see if you are getting fuel to the carbs when it warms up? If not this could mean a clogged gas cap vent.
4. It COULD be your coils as well. Do they feel hot to the touch when this happens?
5. Is the battery new?

 

[panard]

Could be many things but lets start with the basics first.

1. What do you mean by "old compression"?
2. Did you check your ignition timing? Does it advance properly?
3. Did you check to see if you are getting fuel to the carbs when it warms up? If not this could mean a clogged gas cap vent.
4. It COULD be your coils as well. Do they feel hot to the touch when this happens?
5. Is the battery new?

Auto correct put in "old". It is getting fuel (does the same with cap removed), the timing is correct and the battery is good. I will check the coils. The points have a small fit but nothing more. Jay

 

[devilclown]

As a general rule of thumb. When I get an old bike, I always replace points, condenser, coils plugs and install a solid state rectifier. Cant go wrong with putting these new parts in.

Battery good, or battery new?

When was the last time you did routine service to the valves and timing chain tensioner?

How many of the parts I just listed have you installed?

 

[panard]

I replace all the above parts about a year ago. Yesterday I got back to the bike, removed points and cleaned them up. Installed them, set the point gaps but the problem is before the engine reaches LF on compression stroke the points are already open, they open way before that point is reached. Moving the base plate does no good. Is it possible that the timing chain has slipped? I have tried and tried again to set the timing and this happens every time. It will start but runs very poorly. I've tuned this bike several times in the past and never had a problem. Is it even possible to slip time and if so, would these symptoms sound likely?

 

[doode]

If you're worried the cam chain slipped, you can remove the points and advance mech and rotate the engine to LT. The pin on the end of the camshaft should be at 12 or 6 o'clock and you should be able to see the left side piston through the plug hole.
Post a photo if you're not sure

 

[panard]

If you're worried the cam chain slipped, you can remove the points and advance mech and rotate the engine to LT. The pin on the end of the camshaft should be at 12 or 6 o'clock and you should be able to see the left side piston through the plug hole.
Post a photo if you're not sure

I will try that, thank you.

 

[panard]

If you're worried the cam chain slipped, you can remove the points and advance mech and rotate the engine to LT. The pin on the end of the camshaft should be at 12 or 6 o'clock and you should be able to see the left side piston through the plug hole.
Post a photo if you're not sure

I removed the points and advance mechanism but I don't see a pin. One thing I noticed is there are two really rough spots on the lobe the points ride on, like very pitted.

 

[doode]

Post a photo of the area at LT and also pitted spots.

 

[panard]

Post a photo of the area at LT and also pitted spots.

Here is the pits
I will send next pic asap

 

[panard]

here is the pits
i will send next pic asap

lt

 

[panard]

Post a photo of the area at LT and also pitted spots.

LT pic please let me know

 

[doode]

You need to remove the spark advancer unit. Undo the bolt w 10mm wrench. It should slide off. If not then it's stuck.

 

[panard]

You need to remove the spark advancer unit. Undo the bolt w 10mm wrench. It should slide off. If not then it's stuck.

Will do. Thanks

 

[panard]

Will do. Thanks

The pilot pin is at 12 o'clock, back to square one.

 

[panard]

Lt lines up with pin at 12 o'clock

 

[doode]

Well, time to put it back together and see if you can get the points dialed better.

Your spark plug caps are new?

What voltage does your battery read?

What does the battery read while idling?

While idling at 3k rpm?

 

[Yendor]

The Points Cam is TOAST.
The Pitting will cause erratic Motion with the Points Open/Close process.
It is likely to cause bounce in the points.

You need to replace it or convert to Electronics Ignition.

I would convert to Charlie's Place Electronic Ignition or Pameco ( I personally like the Charlie's Place)

The Points are replaced by Magnetic Sensors.
The Points CAM Part is replaced by a part that has an embedded magnet.

No More Points Adjustments Just Set the timing and go.

Both Mfg's have web site you can reference.