XS650 Timing Issues? *VIDEO*

[Yamaha77]

It was a beautiful day here in NYC. Took the bike to a few events. I dont ride this one much (77 XS650) but I took it out. Noticed LOTS of popping noises in the exhaust. A person offered to solve this for me, at cost, saying its the carbs and a sync issue. in the city and a buddy came out to help (see the link below). Can you hear the popping noises? He says its a timing issue only and not the carbs, Any ideas? Ive only had this bike a month and dont ride it much. It sounds like fireworks from the exhaust each time i drive it, and today when I was out, it would drop out of idle and shut off until we put the idle up to about 2k. Any ideas? Im a newbie, esp with Yamahas.

Video of popping sound: https://www.instagram.com/p/BKeO4gIBGkk/?taken-by=jjwilde_

 

[gggGary]

Go thorugh one thing at a time, eliminating might be's til it runs right, check spark, test all ignition components, plugs wires coils condensers points clean gapped no slop on the pivots, set timing with a light at idle check that you have smooth even advance and timing is at the advance timing mark at 3000 rpm on both cylinders. check set valve clearance timing chain tension then check carb idle circuits and sync.

 

[scott s]

I don't understand how he can set the timing without at least a test light. Even better, a timing light.

* Adjust the valves and cam chain. Do this on a cold engine. As in, sat overnight.
* Check and set points gap.
* Check timing with a light.
Then, and only then, attempt any carb tuning, if needed.
Look into installing a Pamco.

 

[Yamaha77]

I don't understand how he can set the timing without at least a test light. Even better, a timing light.

* Adjust the valves and cam chain. Do this on a cold engine. As in, sat overnight.
* Check and set points gap.
* Check timing with a light.
Then, and only then, attempt any carb tuning, if needed.
Look into installing a Pamco.

OK. May I ask, what makes you think it may have to do with the valves or cam chain?

 

[scott s]

You don't set the timing until you've confirmed that the valves are proper. It's just the proper way to tune an engine.
Unless you have done them very recently, confirm valve clearances are right. You shouldn't attempt to set the timing on an engine with improper valve clearances. Plus, you can then rule them out as being a potential problem.
If it were my bike, I'd do exactly what I suggested above.

 

[Yamaha77]

You don't set the timing until you've confirmed that the valves are proper. It's just the proper way to tune an engine.
Unless you have done them very recently, confirm valve clearances are right. You shouldn't attempt to set the timing on an engine with improper valve clearances. Plus, you can then rule them out as being a potential problem.
If it were my bike, I'd do exactly what I suggested above.

Well you guys know better than me, so thats exactly what im going to have done. Unfortunately, with two kids (3 and 8 months) and my own business, which eats up 90% of my time, I cannot possibly do it myself. I'll have to have my trusty mechanic do it.

Btw what are the consequences of driving it as is for a little while?

 

[scott s]

And to clarify: I don't necessarily think there's a problem with the valves or cam chain.
I just think the bike needs tuning. To do a proper "tune up", you set the valves and cam chain, set points, check timing and then sync/adjust carbs. It's just the proper way/sequence to do things.

Any idea when the oil/filters were last done? You could also consider that part of a "tune up". Oil and filter every 1500-2000 miles (I sometimes clean the filter every other oil change). The other stuff once a year, or every ~3,500 miles or so.
Get a Pamco and you don't have to worry about the points/timing. Cabs shouldn't need much, if any, tweaking once set properly. Just frequent oil changes and valve adjustments.....it's how you make these old bikes live long and healthy lives.

 

[scott s]

Well you guys know better than me, so thats exactly what im going to have done. Unfortunately, with two kids (3 and 8 months) and my own business, which eats up 90% of my time, I cannot possibly do it myself. I'll have to have my trusty mechanic do it.

Btw what are the consequences of driving it as is for a little while?

If you're shop doesn't know these things, find another shop.

I would NOT continue to ride it like this.
Nope....not at all.
You could do these things....an hour or two is all it takes.

 

[Yamaha77]

If you're shop doesn't know these things, find another shop.

I would NOT continue to ride it like this.
Nope....not at all.
You could do these things....an hour or two is all it takes.

I have plainly said I dont have the time to fix this, even an hour (I prefer to give any spare time to my kids AND my wife and I have an agreement about what goes on with my bikes) so I will have it taken care of by someone I have already reached out to, this week. Thankfully I have two other fully functioning bikes, a 73 Honda cb 500f and a 73 Honda CB 750 so I'll use one of them if this isnt fixed in time. But i REALLY like riding my xs. its a great bike.

 

[scott s]

I have plainly said I dont have the time to fix this, even an hour (I prefer to give any spare time to my kids AND my wife and I have an agreement about what goes on with my bikes - so I will have it taken care of by someone I have already reached out to, this week. Thankfully I have two other fully functioning bikes, a 73 Honda cb 500f and a 73 Honda CB 750 so I'll use one of them if this isnt fixed in time.

Why ask what's wrong or how to fix it then? Just take it to the shop.
In the time it takes to get it there, get a ride home and back to get it, it could be done at home. But, hey.....it's your time and money.

 

[Yamaha77]

Why ask what's wrong or how to fix it then? Just take it to the shop.
In the time it takes to get it there, get a ride home and back to get it, it could be done at home. But, hey.....it's your time and money.

Im having something else done to it this week.

The reason I ask "why" is, it makes me better able to communicate with my mechanic, and when my youngest son reaches preschool age and im free to dither with bikes again, I will have all of this info in my back pocket. Ppl get sick and go to the doctor but they STILL want to know the ins and outs of what the issue is that plagues them. Human Curiousity. Plus, I might be able to pass on this info and help someone else out

 

[gggGary]

Yes riding it running like that will cause damage, one way or another. A good shop that's used to working on old tech should figure out the problem in a paycheck or 2 LOL

 

[gggGary]

Did this problem develop right after that petcock got replaced?
What do the plugs look like?

 

[Yamaha77]

Did this problem develop right after that petcock got replaced?
What do the plugs look like?

The petcock wasnt replaced. the gasket in it was and it doesnt leak anymore. Nah the popping sound started a week after i owned it. At one point the fuse came loose and I lost power. I didnt realize the fuse was loose and kept trying to kick start it. Maybe that threw the timing off, but it always made that popping noise when I got it back from the mechanic who only had it to put new tires on it and new handlebars. I dont understand what happened because a few weeks ago it was running like this:

https://www.instagram.com/p/BIu-Wg8BoQ9/?taken-by=jjwilde_

and when i got it back it ran like shit. As you can see, it is running like a dream a month ago. Now its backfiring and popping like mad.

 

[gggGary]

anything we say is a guess, If it was mine I'd start with a compression test then go through the steps listed above. check air filters and see what jetting is in the carbs. 2 into 1 pipes on XS's scare me if I don't know the carb rejetting was done properly.

 

[Yamaha77]

anything we say is a guess, If it was mine I'd start with a compression test then go through the steps listed above. check air filters and see what jetting is in the carbs. 2 into 1 pipes on XS's scare me if I don't know the carb rejetting was done properly.

But as you can see, it was running fine. I know from the previous owner the jetting is proper. I have all the specs from him. Something was either tampered with or maybe its the plugs. I know I flooded the carbs today. maybe Ive been doing that all along.

Also the electric start tries to engage the engine but wont. Only the kickstart does. Im thinking its the plugs (going back to my days of building vintage cars and fouling spark plugs left and right).

 

[hmusket]

I had a problem last year similar to what you are describing, ended up being a loose, or maybe frayed power wire to the left coil, don't remember which. Do as gggGary suggested in his first post, pull the tank off and examine the wiring, the orange, gray and black wires, from the points to the coils to make sure they're tight, no breaks. Should only take 15-20 minutes at the most.

 

[Yamaha77]

I had a problem last year similar to what you are describing, ended up being a loose, or maybe frayed power wire to the left coil, don't remember which. Do as gggGary suggested in his first post, pull the tank off and examine the wiring, the orange, gray and black wires, from the points to the coils to make sure they're tight, no breaks. Should only take 15-20 minutes at the most.

And this made the bike produce popping noises from the exhaust? A loose wire?

 

[Yamaha77]

And to clarify: I don't necessarily think there's a problem with the valves or cam chain.
I just think the bike needs tuning. To do a proper "tune up", you set the valves and cam chain, set points, check timing and then sync/adjust carbs. It's just the proper way/sequence to do things.

Any idea when the oil/filters were last done? You could also consider that part of a "tune up". Oil and filter every 1500-2000 miles (I sometimes clean the filter every other oil change). The other stuff once a year, or every ~3,500 miles or so.
Get a Pamco and you don't have to worry about the points/timing. Cabs shouldn't need much, if any, tweaking once set properly. Just frequent oil changes and valve adjustments.....it's how you make these old bikes live long and healthy lives.

I just re-read this. Thanks a million Scott. Really well said.

 

[scott s]

I know from the previous owner the jetting is proper. I have all the specs from him. Something was either tampered with or maybe its the plugs.

Also the electric start tries to engage the engine but wont. Only the kickstart does. Im thinking its the plugs (going back to my days of building vintage cars and fouling spark plugs left and right).

If you have the specs, post them. It would be very helpful when trying to decipher all this.
And just because he says they're right doesn't make it true.

There's a fix for the electric starter problem but I won't bother posting it. Just have the shop fix that, too.

And kicking it repeatedly won't change the timing.