Timing Question

[vincemoccio]

Hi All,

New to the forum. Quick question for everyone regarding my current project.

I currently rebuilt (top end rebuild, new electrical etc.,) a 78 XS650. The bike fires right up and rides nice. Only problem is at times the bike dies while idling or when I pull in the clutch while riding in first gear coming to a stop. I've already increased my idol jet to 45 (mixture screws at 1.5 turns, cleaned the carbs, adjusted the valves, purchased new spark plugs, ensured there were no leaks.

I'm assuming there is a timing issue because I installed a new Hugh's Handbuilt PMA. Any one have an opinion on wether or not this is the problem? If so, could someone guide me in the direction of where I can learn to do the timing. I've never done this before.

Thanks!

 

[I am Carbon]

Hi All,

New to the forum. Quick question for everyone regarding my current project.

I currently rebuilt (top end rebuild, new electrical etc.,) a 78 XS650. The bike fires right up and rides nice. Only problem is at times the bike dies while idling or when I pull in the clutch while riding in first gear coming to a stop. I've already increased my idol jet to 45 (mixture screws at 1.5 turns, cleaned the carbs, adjusted the valves, purchased new spark plugs, ensured there were no leaks.

I'm assuming there is a timing issue because I installed a new Hugh's Handbuilt PMA. Any one have an opinion on wether or not this is the problem? If so, could someone guide me in the direction of where I can learn to do the timing. I've never done this before.

Thanks!

probably a combination of things.
did you change the timing before installing the PMA?
It could be timing.
have you timed it?
did you find TDC and mark it on rotor?

 

[vincemoccio]

Thanks for the quick reply. No, i didn't not adjust timing. Can you guide me in the right direction on how to adjust the timing? I can't seem to find it in the "How to" section...

Vince

 

[fredintoon]

Hi Vince,
did you adjust the throttle stop to set the idle at ~1,000 rpm?
Any bike will stall if the carbs are completely shut.

 

[I am Carbon]

Thanks for the quick reply. No, i didn't not adjust timing. Can you guide me in the right direction on how to adjust the timing? I can't seem to find it in the "How to" section…

Vince

the timing process is simple to perform.
You will need timing light. if it has a advance adjustment on the light set it at zero.
You will need to find TDC on rotor.
For that you will need a piston stop.
You will need the sticker that came with the HHB PMA and stick it on the cover where it needs to be.
Once you have located TDC on rotor you will need the left cam cover removed so you can make the adjustment on the timing adjustment plate.
connect the timing light to a battery and left sparkplug wire.
Start the engine let it idle around 1200 to 1300 rpm
You will want the TDC mark set at the fire mark on the sticker.
turn off the engine before making the adjustment.
Here is some videos I made that will help you in this.
finding TDC

finding TDC

I was checking timing not really a tutoral, also this a pamco prototype ignition for a rephased engine so you dont have to check both sides like I did just left sparkplug

you will need to rotate the timing adjustment plate clock wise to advance or rotate counter clock wise to retard timing.

 

[SpongeBobbed]

Carbon, thanks so much for the instructions on the bottom. I put a PMA system on my bobber and TDC was incorrectly marked. I tried doing my valves and everything was getting really messed up. After realizing my TDC was off I watched your video, made myself a little piston stop in about 5 mins, and correctly found TDC about 5 minutes later. I would have spent hours looking at the manual if it wasn't for this site, and in particular your post. Thanks!

 

[I am Carbon]

Carbon, thanks so much for the instructions on the bottom. I put a PMA system on my bobber and TDC was incorrectly marked. I tried doing my valves and everything was getting really messed up. After realizing my TDC was off I watched your video, made myself a little piston stop in about 5 mins, and correctly found TDC about 5 minutes later. I would have spent hours looking at the manual if it wasn't for this site, and in particular your post. Thanks!

Sweet! good to hear. YW