First motorcycle and a cylinder not firing.

Kevin Werner

Amatuer
Top Contributor
XS650.com Supporter
Messages
3,432
Reaction score
14,371
Points
513
Location
Sheboygan, WI
Yes, both seem to be running the same (as far as i can tell with it only running for 1-2 mins before shutting down), clanging is still there, however, want to try 5twins method of tightening the cam tension before investigating things deeper. pilot is 27.5 supposedly, according to rebuild kit.
I recently found out that a small pilot jet causes black plugs. I suspect that when the pilot circuit does not supply enough fuel to idle, you adjust your idle higher (throttle open more) and the needle jet starts supplying fuel. Double check you pilot jets next time the carb bowls are off. Physically remove them carefully and find the size number and insure they are clean.
 

Thursty

XS650 Enthusiast
Messages
87
Reaction score
83
Points
18
Location
Ontario
I don't see much point in removing the whole tensioner housing, there's not much to see in there. But, you can (and probably should) remove the adjuster screw, plunger, and spring assembly from it, it just screws out. What you'll be looking for is the damper washer, a copper washer placed on the plunger rod to quiet the operation of the unit. Many times they are missing and then the tensioner can make noise, sounding like loose valves .....

View attachment 226143

If missing, this will also allow the end of the plunger to come out past the end of the adjuster screw during operation. If you loosen the adjuster so it's flush with the plunger, you will have the chain set too loose.

I find the "book" method for setting the cam chain tension very confusing and easy to screw up. The first time I tried it many years ago, I ended up with the chain way, way too loose. Every time I rotated the engine, the rod would pop out past the adjuster, so I loosened it to make it flush. Another engine revolution would have the same thing happening so I'd loosen the adjuster more, etc., etc. My setting ended up being way too loose. I started the engine and it rattled like the valves were loose. There had to be a better way, and there is - you check and set the tension while the engine sits there idling. I borrowed and adapted this from the cam chain adjustment instructions for Yamaha's big singles .....

View attachment 226144

The actual instructions can't be applied. You can't set the motor on the "T" mark. There is no spot during a 650 engine revolution where all the valves are closed and there is no tension on all the rocker arms. It's the note at the bottom that's important. We can do this on our 650, and it's a pretty much foolproof method for checking and setting the chain tension. You want to see a small amount of in-out movement on the plunger, maybe 1 to 2mm. If it moves more, the chain is too loose, if it moves less or not at all, the chain is too tight.

Easiest way to do the adjustment is to tighten the adjuster until the rod almost stops or stops moving, then loosen it back up until you get your 1 to 2mm of in-out movement. Don't worry too much whether the rod is flush with the end of the adjuster screw, that can vary due to worn (or missing) parts.
You're a gem, sir. This eliminated the clanging. The problem you described in setting the chain tension in your earlier days, was exactly the problem I was facing. How do these books get published with such critical information being so misleading haha? Either way, your method of setting cam tension worked miracles and eliminated the clanging. As for the left cylinder, it seems to be firing much much much better now! I still wonder if it is a bit weaker than the left cylinder though, if thats even possible? could that be due to the ignition system, weak wiring, weak coils, weak spark etc? Either way, both cylinders seem to be firing much more consistently (im going to time it again now that the cam tension is properly set), and both pipes get hot as hades. Next step will be jetting the carbs accordingly.

Thanks everyone for the help. By eliminating potential problems one at a time, I've been able to pinpoint what the real problems are, and rectify them.

Heres a video of it running, in hopes that some of you might be able to hear something that should be addressed. Such as the fast backfiring at lower, mid-range rpms(@47 seconds).
 

5twins

XS650 Guru
Top Contributor
Messages
23,843
Reaction score
20,301
Points
813
One of the first things I do on one of these when I get it is replace the spark plug caps and plug wires (if possible). At the very least, you should re-do the plug wire connections at both the plug cap and the coil. Cut about 1/4" off the ends of the plug wire to get to some fresh wire, then strip about another 1/8" off the insulation and fan the wire strands out in a radial pattern like so .....

Plug Wire End.jpg


This will insure a good connection. Now you can screw the plug cap back on and install the other end into the coil.

If your plug caps are the originals, it's best you replace them. NGKs are the standard of the industry and not very expensive. I would recommend getting the LZFH non-resistor cap ......

NGK LZFH.jpg


The spark plug we usually run is the non-resistor BP7ES, but NGK has discontinued them, at least on this side of the "pond", so finding them is getting difficult. What is still readily available is the BPR7ES, the resistor version. You can use it with the non-resistor LZFH cap. You only want one instance of resistance in your spark plug line - plug, cap, or wire. More than one can be too much and start choking off your spark.
 

5twins

XS650 Guru
Top Contributor
Messages
23,843
Reaction score
20,301
Points
813
Your rough and ratty running may be due in part to having straight pipes and no mufflers (no back pressure). Straight pipes can be difficult to tune for and well, you haven't done any tuning to speak of (jetting changes).

When you add mufflers (and I recommend you do), for main jets I'd get 130's and 132.5's. One of them should be what you need. Your 27.5 pilots are good, one size larger than stock. That's the usual change you make. The last needed change will be leaning the needles one step to lean out the midrange a bit. Larger mains and pilots bleed over into the midrange and make it too rich. Basically, your carbs have 3 circuits and they overlap slightly. Changing one effects that overlapped portion of the circuit next to it .....

Carb_Circuits.jpg
 

Jan_P

XS650 Guru
Top Contributor
Messages
1,911
Reaction score
3,408
Points
263
Location
Sweden
Nothing major at this point in time You have a talent for this.
??? A Leak left side cylinder head ?? I would check the bolts with a torque wrench after this long standstill
If it starts leaking it can be difficult to stop
Please google ...some are loosening them and tighten,
 

Thursty

XS650 Enthusiast
Messages
87
Reaction score
83
Points
18
Location
Ontario
Your rough and ratty running may be due in part to having straight pipes and no mufflers (no back pressure). Straight pipes can be difficult to tune for and well, you haven't done any tuning to speak of (jetting changes).

When you add mufflers (and I recommend you do), for main jets I'd get 130's and 132.5's. One of them should be what you need. Your 27.5 pilots are good, one size larger than stock. That's the usual change you make. The last needed change will be leaning the needles one step to lean out the midrange a bit. Larger mains and pilots bleed over into the midrange and make it too rich. Basically, your carbs have 3 circuits and they overlap slightly. Changing one effects that overlapped portion of the circuit next to it .....

View attachment 226170
Thanks a ton! I do plan on getting mufflers, but not just yet... Mostly because i 'plan' on making my own. And i would put the originals on, but, like stated before, they gots big holes... In the meantime, do you think 130s and 132.5s would still be sufficient enough to at least dial things in with the straight pipes?

I'm going to order new plug caps tonight. I'll try that for now and see where it leads me. If needed, I'll order new coils and line. Unless you recommend I just go ahead with the coils and line?
 

Thursty

XS650 Enthusiast
Messages
87
Reaction score
83
Points
18
Location
Ontario
Nothing major at this point in time You have a talent for this.
??? A Leak left side cylinder head ?? I would check the bolts with a torque wrench after this long standstill
If it starts leaking it can be difficult to stop
Please google ...some are loosening them and tighten,
A left cylinder head leak test? Is that what you are suggesting? I will definitely take your suggestion and check. Should I change out gaskets while I'm at it?

I probably wont do this quite yet, as other things are higher on the checklist. However, I'll keep this in mind and definitely get around to it at some point this coming winter.
 

Thursty

XS650 Enthusiast
Messages
87
Reaction score
83
Points
18
Location
Ontario
Your rough and ratty running may be due in part to having straight pipes and no mufflers (no back pressure). Straight pipes can be difficult to tune for and well, you haven't done any tuning to speak of (jetting changes).

When you add mufflers (and I recommend you do), for main jets I'd get 130's and 132.5's. One of them should be what you need. Your 27.5 pilots are good, one size larger than stock. That's the usual change you make. The last needed change will be leaning the needles one step to lean out the midrange a bit. Larger mains and pilots bleed over into the midrange and make it too rich. Basically, your carbs have 3 circuits and they overlap slightly. Changing one effects that overlapped portion of the circuit next to it .....

View attachment 226170
Will baffles work as a temporary substitute for mufflers to get the engine tuned better? Thanks.
 
Last edited:

Jan_P

XS650 Guru
Top Contributor
Messages
1,911
Reaction score
3,408
Points
263
Location
Sweden
A left cylinder head leak test? Is that what you are suggesting? I will definitely take your suggestion and check. Should I change out gaskets while I'm at it?

I probably wont do this quite yet, as other things are higher on the checklist. However, I'll keep this in mind and definitely get around to it at some point this coming winter.
No No No
I believe I could se a black band oil coming out on the left side under the cylinder head
The bolts sometimes needs tightening I don't loosen I check so they are tight
please google

Something like that

https://xs650temp.proboards.com/thread/1858/re-torque-head


The time-honored 650 Society method is to remove one fitting at a time, lube it, bring it to book torque, then do the next fitting. Then go to 30 pounds on the large acorn nuts, as 5twins says. The only difficult fittings are the ones next to the sparkplug holes. Either use an offset drive adapter and reduce your torque reading in straight proportion to the length you've added with it, or bend a piece of 1/4" square stock into a drive head and pull 12" from the drive center with a good quality spring scale.
 

Thursty

XS650 Enthusiast
Messages
87
Reaction score
83
Points
18
Location
Ontario
No No No
I believe I could se a black band oil coming out on the left side under the cylinder head
The bolts sometimes needs tightening I don't loosen I check so they are tight
please google

Something like that

https://xs650temp.proboards.com/thread/1858/re-torque-head


The time-honored 650 Society method is to remove one fitting at a time, lube it, bring it to book torque, then do the next fitting. Then go to 30 pounds on the large acorn nuts, as 5twins says. The only difficult fittings are the ones next to the sparkplug holes. Either use an offset drive adapter and reduce your torque reading in straight proportion to the length you've added with it, or bend a piece of 1/4" square stock into a drive head and pull 12" from the drive center with a good quality spring scale.
ohhhhh! what time in the video? id like to watch it back. I did spill a bunch of oil out while opening the right side engine cover just prior to this, so, could be that?
 

Thursty

XS650 Enthusiast
Messages
87
Reaction score
83
Points
18
Location
Ontario
Not a good picture please check inside blue ring
oil or shadow


View attachment 226181
I feel like i would have noticed that if it was oil, but i will double check tomorrow to make sure. Also, i read through that link you gave me. I will definitely loosen and re-torque the head nuts. I will also remove them and clean them one at a time. Thanks
 

5twins

XS650 Guru
Top Contributor
Messages
23,843
Reaction score
20,301
Points
813
Yes, re-torquing the head bolts is a necessary maintenance item on these, especially when you first get the bike because it probably wasn't done in a long time, if ever, lol. There's also those funky rubber/metal seal washers Yamaha used on the outside 4 acorn head nuts. Those 4 outside studs drain oil from the topend back down into the crankcase so they need a sealing washer of some sort under the acorn nut. Unfortunately, Yamaha made a poor choice here. Sure, the rubber/metal washer does seal, but it's too soft to keep the acorn nut tight so they always loosen up. This causes head gasket leaks and they are quite common on these bikes. Now that you have one, you'll probably be looking closer at any you happen to see. In particular, look at the head gasket, you'll find many that are leaking.

So, you need a washer soft enough to seal but hard enough to keep the nut tight. Many other manufacturers drain oil back to the crankcase through head studs like this and they use copper sealing washers. These work well, seal but keep the nut tight, and are what you should swap on yours .....

ButtonHeads.jpg
 

Thursty

XS650 Enthusiast
Messages
87
Reaction score
83
Points
18
Location
Ontario
Yes, re-torquing the head bolts is a necessary maintenance item on these, especially when you first get the bike because it probably wasn't done in a long time, if ever, lol. There's also those funky rubber/metal seal washers Yamaha used on the outside 4 acorn head nuts. Those 4 outside studs drain oil from the topend back down into the crankcase so they need a sealing washer of some sort under the acorn nut. Unfortunately, Yamaha made a poor choice here. Sure, the rubber/metal washer does seal, but it's too soft to keep the acorn nut tight so they always loosen up. This causes head gasket leaks and they are quite common on these bikes. Now that you have one, you'll probably be looking closer at any you happen to see. In particular, look at the head gasket, you'll find many that are leaking.

So, you need a washer soft enough to seal but hard enough to keep the nut tight. Many other manufacturers drain oil back to the crankcase through head studs like this and they use copper sealing washers. These work well, seal but keep the nut tight, and are what you should swap on yours .....

View attachment 226191
https://xs650direct.com/products?make=22&year=12&model=60&category=105&page=2

Is the top end copper sealing washer kit what you would be referencing as needing replaced? This supplier is where I get my jets, and where I will probably be getting my wiring harness and new coils. If that's referencing the same washers as you, I'll probably get it aswell.
 

5twins

XS650 Guru
Top Contributor
Messages
23,843
Reaction score
20,301
Points
813
No, that kit has all the other copper washers but not the ones for the acorn nuts. XS650Direct does sell them. They have the original rubber/metal type (which you don't want) and brass ones. The brass ones are fine, better than the rubber/metal originals .....

https://xs650direct.com/products?make=22&year=12&model=60&category=105&page=1

I just bought copper ones off eBay, they were much cheaper. This isn't something you need to change immediately so the wait for them to come from China is no big deal .....

https://www.ebay.com/itm/1551666723...H+bkfcnPSlYFkpr2LwlDKzB/4=|tkp:Bk9SR-S-7fnvYA

Just be aware that you do want to change them eventually because the head nuts will constantly come loose with the rubber/metal ones.
 

Thursty

XS650 Enthusiast
Messages
87
Reaction score
83
Points
18
Location
Ontario
No, that kit has all the other copper washers but not the ones for the acorn nuts. XS650Direct does sell them. They have the original rubber/metal type (which you don't want) and brass ones. The brass ones are fine, better than the rubber/metal originals .....

https://xs650direct.com/products?make=22&year=12&model=60&category=105&page=1

I just bought copper ones off eBay, they were much cheaper. This isn't something you need to change immediately so the wait for them to come from China is no big deal .....

https://www.ebay.com/itm/155166672311?var=455348255804&hash=item2420a785b7:g:VI4AAOSwmOZbh7Ki&amdata=enc:AQAHAAAAoKaITiQdAn+zqeRUKHa9JAWSGnSHFyqDXL5N8mno4WNgKl8OtRHnyDI795IusEILaPcNmYgkgBoe/XoejUkT0VCnJyIlk7XzMDQjcnFAVOX+YhOslqHbdT2KffgwNz4UNg2X03thC/uNFul2WnmNEEJ2EJjz71VMxz32sVddIAhZThs2e/XBtLHjTEB1gWH+bkfcnPSlYFkpr2LwlDKzB/4=|tkp:Bk9SR-S-7fnvYA

Just be aware that you do want to change them eventually because the head nuts will constantly come loose with the rubber/metal ones.
Sounds good. I will probably get the xs650 direct brass ones. Being that I am from north of the border, ebay usually rips me with shipping, and then I get ripped again with duties. xs650 is not far from me, so quick and cheap... Thanks. Also, having a hard time finding non resistor caps up here... Everything im finding is like $3 a cap, with $20+ shipping... such a pain...
 
Top