Timing with pamco -non running

TAlber8

XS650 Addict
Messages
113
Reaction score
19
Points
18
Rebuilt 74 bike was running great, cam chain tensioner loosened, timing got whacked out and jumped a tooth while trying to start. Kick start only.

Got cam timing corrected, cam chain tensioned, valave clearances good. Leakdown seems to be ok on top end so don't think I hit valve....

Still doesn't want to start and has a major kick back.

How can I dbl check timing with pamco if bike isn't running?
 
I double checked cam timing and it seems right.

Reassembled, dbl check cam chain tension... no luck, major kick back.

I took out sparkplug sand zip tied to find and turned motor over by hand. It seems that the spark is actually quite retarded... what would that have to do with the major kickback?
 
Closing this thread... since I got the ignition part figured out


Glad that you have got the ignition issue solved but would you mind telling us what you did to fix the ignition problem so that I and future viewers will have some idea of what the problem was and what was done to resolve the issue .
if you just close threads off without any feedback or closure you're going to find folk less enthusiastic to help you with future problems you are going to need help with
 
I had referenced above but didn't have detail.

I pulled the plugs and zip tied to the fins to keep grounded, and turned motor over by the flywheel slowly and eyeballing the spark.

It consistently appeared to be retarded.. although I question this as I still have kickback symptom. Next stop is dbl check TDC with a stop
 
I had referenced above but didn't have detail.

I pulled the plugs and zip tied to the fins to keep grounded, and turned motor over by the flywheel slowly and eyeballing the spark.

It consistently appeared to be retarded.. although I question this as I still have kickback symptom. Next stop is dbl check TDC with a stop


if you haven't found the cause of the problem it makes no sense closing the thread by saying that you have the ignition figured out ??

You clearly haven't ;)

It makes things extremely difficult for us if you keep starting fresh threads for the same problem. it means that we haven't any idea what has gone before , what you have already tried and the results of that.
On ther point of information could you please list the details of your bike in your 'signature' so that it is visible as reference in all of your posts and we don't have to keep searching back through your posts to gather information

First of all you cannot tell to what degree the static ignition may or may not be retarded by watching for the arc on your plugs unless the cam timing is grossly out you'll learn nothing of any consequence. if the pistons are at TDC top dead centre and the notch on the camshaft is vertical then your static timing is fine the issue lies elswhere. It would be helpful for us if you show an image of the end of your camshaft at TDC so that we can all verify this

Even with your timing retarded the engine will still attempt to start . it will cough and splutter and even misfire but you'll get something!

As far as I can make out you have a spark and you clearly have compression but have you tried starting the engine with some EasyStart squirted into the carb inlets ?
 
Sorry will look into adding the signature.

Below is how it was and spark was arcing near TDC (havnt moved timing plate since the last time it ran well). This pic is just before TDC
Movin the cam one tooth seems equal distance from verticals and places the arc very advanced.

I was not able to reassemble, move timing and try to run like that tonight..

Prior to the cam chain slipping it seemed to run really well, starting first kick always.

I'm realizing now that this cam chain probably is stretched a bit too making this more difficult.

Also to note: I was gingerly about kicking it over after this weekends re assemble. The kickback I had before scarred me!
 

Attachments

  • IMG_8640.JPG
    IMG_8640.JPG
    260.6 KB · Views: 150
Ha ...I am completely with you on the kick back anxiety :D
Mine is so fierce that I always use the leccy start now.

I shouldn't worry too much about chain stretch ...you can adjust for any slight stretch with the chain guide tensioner.

I'm afraid I cannot follow your explanation and I'm not sure which end of the camshaft you have shown so it doesn't really help
I'm still not convinced that you have the timing set correctly :)

Have you got the camshaft installed the correct way round ?
The threaded end of the camshaft with dowel pin hole should face the right hand side of the engine ( ie right hand side as you sit on the bike )
The camshaft timing notch should be on the left hand side

To correctly time the camshaft you need to set the Left hand cylinder at TDC on its compression stroke.
Check that the TDC mark on the rotor is lined up at TDC
Now check the Left hand side cam shaft sprocket face and make sure that the large timing notch is facing vertically at 12 oclock.
If it is then your static timing is spot on and your camchain is fitted correctly.

I'm sure that you have got this correct but without any images or a coherent description it wouldn't hurt to do another check so that we can definitely eliminate this in our minds as we cannot see your engine to check for ourselves.
timing.jpg
 
That was right had, advance side, of the motor with right cylinder at TDC, so 360 degrees out from the instructions (turn motor over so left is at TDC the pin would be verticle). The pic is taken just before TDC, so a few more degrees and it straightens.
I tried last night moving one tooth and that seems way off, it puts the pin closer to 1oclock, although I did not get photo.
 
if you have the cam exposed why are you using the pin to align TDC and not the Notch ?

In your image I can just make out the pin I think at 5 oclock yes ? It should be at 12 oclock. at TDC not 5 oclock
Your image is completely unhelpful I'm afraid.

You are going about this in the wrong way .......Please just follow the instructions above and do it as per the Yamaha manual .
You can tell when a piston is coming up to TDC on its compression stroke by simply removing the spark plug and putting your finger over the hole. You will feel the compression building

If you are still changing the cam chain then you must be able to see the camshaft.

Please would you post an image of the camshaft at exactly TDC on the left hand cylinder and make sure that the whole of the engine and camshaft is in the image so that we can verify your cam is in correctly.
 
probably would have been a good idea to have kept the other thread going........

A stretched cam chain, (especially if it is stretched enough to jump a cog), will alter the timing a lot. There have been reports that points plates have been notched to get extra movement to compensate for an overly stretched chain...........This same principal will apply to the pamco, or any can driven timing ignition
 
Please would you post an image of the camshaft at exactly TDC on the left hand cylinder and make sure that the whole of the engine and camshaft is in the image so that we can verify your cam is in correctly.

The engine still assembled in the frame so I was using the pin on the right side of motor as a guide.

Is it correct that it doesn't matter which cylinder is on compression since it's a Electronic ignition?

I reassembled tonight and with the plugs out and grounded, although crude, the spark seems to be firing between F and TDC marks... so not drastically off. Even if not perfect. I turned it over numerous times like this.

But when I plugged it up and turned on gas, first kick hit me back.

Is it possible the e-advance is activating at super low rpm? Where I dont see it turn over manually but maybe kicking is enough? Seems unlikely but...
 

Attachments

  • IMG_8647.JPG
    IMG_8647.JPG
    184.2 KB · Views: 150
  • IMG_8648.JPG
    IMG_8648.JPG
    142.8 KB · Views: 143
The engine still assembled in the frame so I was using the pin on the right side of motor as a guide.

Is it correct that it doesn't matter which cylinder is on compression since it's a Electronic ignition?

.

yes it matters .the camshaft isn't symetrical so it has to be aligned correctly with the crankshaft or the valves are not going to open and close in correct sequence with the spark. .do you have a workshop manual ?

Have you fitted the pamco correctly ?
have a read of this .https://www.hughshandbuilt.com/2012/05/30/pamcopete-277-ignition-install/
 
Last edited:
yes it matters .the camshaft isn't symetrical so it has to be aligned correctly with the crankshaft or the valves are not going to open and close in correct sequence with the spark. .do you have a workshop manual ?

Have you fitted the pamco correctly ?
have a read of this .https://www.hughshandbuilt.com/2012/05/30/pamcopete-277-ignition-install/

I don't think he has a 277 converted engine. You cannot static time an E-Advancer ignition. If the ignition is a PAMCO, instructions are on www.yamahaxs650.com
 
I don't think he has a 277 converted engine. You cannot static time an E-Advancer ignition. If the ignition is a PAMCO, instructions are on www.yamahaxs650.com

thank you for the info Pete I initially assumed that the po has not set TDC correctly given the number of references to jumped teeth and spark being off etc.
I know nothing about setting up a pamco which is why I referred him to Hughs page which appears to have a comprehensive guide that he can check.

As regards to setting the cam to the pistons I assumed that he has a standard engine but again the po has not supplied all the information that has been asked of him, so I just copied the instructions from the Haynes Yamaha xs650 workshop manual which I again assumed would be relevant.

My feeling is that the cam is set correctly to TDC and the chain didn't jump and the problem ,if he has one, is due to the pamco either being faulty or not having been set up correctly.

I'll leave to you and others now as I think I have exhausted what little knowledge I have from a single engine build 4 years ago ;)
 
For future reference Peanut........"Tech Menu"........"Electrical"........"Pamco Ignition - wiring diagrams, faq's, tips,troubleshooting ect"
 
Ok.... we're all good.

The cam chain had for sure jumped when the tensioner loosened. I had parked it for 6 months until now.

So I reassembled ignition after the above picture and was able to get it to start. I think last week when I had done so (after correcting the cam timing) that I had mistaken a little burp in the kickstarter for a precursor to a large kickback like I had before (after the cam slipped)

I got it running, barely, then re-timed it with a light. Now it's good to go, took it out for 20 mikes or so. Still has its issues lol, but I think the timing is back in order.

One interesting note was that the old timing setting from before, when it ran great, was way off now. I assume it was the cam chain taking some abuse and the ignition itself has some loose tolerances so I guess reassembly doesn't guarantee exactly the same. Attached is a pic where the black lines were around the original timing placement (which had originally been tuned with a light and ran well)



Thanks everyone for the inputs.
 

Attachments

  • IMG_8659.JPG
    IMG_8659.JPG
    194.2 KB · Views: 151
  • IMG_8668.JPG
    IMG_8668.JPG
    323.6 KB · Views: 120
Back
Top