my adventure into adjustments

[WELDFAN]

hello fellow xs owners, I am getting ready to make the rounds of adjustments on my xs. I had recently done a pma swap and battery elimination with no problem and dove into making custom stator covers. I started to have a slight noise in one of my valves and realize it is probably over due for cam chain tension, valve, carb adjustment and due to the pma swap will need the timing adjustment.. which if im doing one might as well do all adjustments. this thread will be my share of problems and how I tackle situations, also it will be my area to hopefully get some tips and answers to my rookie questions. I had been laying low over the holiday season and with the recent purchase of a house had to put my poor bikes aside (though i did get to do a motor swap on the mini bike ) with the new house came a beautiful drive in climate controlled garage so my life has changed from backwoods tarp garage to what i think is the cats meow. i look forward to chatting with some of the best.

 

[WELDFAN]

so the first thing i ran into after the pma swap was a noise in one of the valves. i right off pulled the cover and made sure that it is getting oil. when i saw it wet i know that going through my adjustments will be the best place to start without pulling the motor. lately me and my fellow hooligans have been kinda spread in projects, going to pick up what i believe is a 71 xs650 in the near future so filthy can rebuild his xs named terry. we needed a motor for terrys last one was ran to the ground doing some nasty burnouts. hopefully soon ill have a thread for the rebuild. dirty is working on a mutt of a triumph bobber, i have been getting ready to start my triumph build and gsxr rebuild... throw filthy's model A rat rod getting ready to kick off we all have been busy. i now have time to start the adjustments and read up on allot of the threads. im going to start today with my cam chain tension adjustment. i thank littlebill31 for his thread that kicked off my reading @ http://www.xs650.com/forum/showthread.php?t=13058

 

[WELDFAN]

https://www.facebook.com/photo.php?v=10201920876001716&set=vb.1178709559&type=2&theater

please ignore this link if it is not viewable. trying to get it to upload or be viewable. mini bike burnout... had to test it before the ice races

 

[5twins]

Your top end noise could be entirely related to the cam chain setting. If they get too loose, they rattle just like loose valves. The easiest way to test this theory and also to set the chain tension properly is to do it while the engine is idling. If it is too loose, tightening the adjuster will make the noise go away, and you'll be able to hear it happen. This method also insures you don't make the chain too tight. You want to see a small amount of in-out movement on the plunger, maybe 1 to 2mm. If it stops moving, you've set it too tight.

 

[Dakota_Lew]

I have never bought a used 650 that didn't have a loose cam chain. It seems to me to be a comical universal idiosyncrasy with used XS's, easy fix, but most seem to not do it and except the "knock".

 

[WELDFAN]

thanks 5twins, thats exactly why i started with that. i am getting ready in a few minutes to start it up and see what i can do. i have it cold set to a better tension than it was but stayed away from going to thew top end of tight till it is running and slightly warm. i had posted on the thread link above with a ? it was questioning when the tension is good if the rod sticks past end of adjustment nut, is this a sign that the chain is starting to wear too much? just trying to get a feeling on how to tell when it is time to change the chain.

 

[WELDFAN]

kinda hard getting a good feel for where i should set. i went tight till it the rod play started to stop then backed off immediately till i saw a throw in the rod right around 1mm. i then tried loosening to see if i could find a rod play of 2mm or more and was not able to get more than the 1mm. it did directly affect the sound i have but did not completely eliminate it. i am kinda concerned for how much i had to adjust it to originally get it where it is now. i will continue with the valve lashing, timing and carbs but have a slight concern an over slacked cam chain could have caused excessive wear.

 

[5twins]

I know the manual states to adjust the tensioner with the motor off so the plunger is flush with the end of the adjuster screw. Well, it doesn't always happen that way. There were no fewer than 5 different tensioner assemblies used over the years. Some of these bikes have had parts from different ones mixed and matched. That can throw off the rod position at proper chain tension. There's also a damper washer on the rod and there were two different ones of those used, one thicker than the other. Some find the damper washer is missing which can cause excess noise.

You might want to pull the adjuster screw out and verify that you do have the damper washer there. Without one, the rod would stick out more than flush and there could be more noise as well. If the washer is there then yes, you may be in need of a new chain. By about 20K, most of the originals are shot, not because they were a bad part, but because nobody bothered to keep them adjusted and maintained. You should check the chain about every 1000 miles. I do mine at every oil change.

 

[jonny Reb]

I just did my top end after I couldn't stop my head gasket leak by re-torquing the head bolts anymore on my '81 Special... I'm glad I did... I had always had cam-chain noise, even with the rod set flush (1mm movement included). When I got the head apart, the dampener in the front of the case was busted- the rubber had come off and slid down, so the chain was just slapping the exposed aluminum mount... hence the noise. I don't want to be a downer, but it might be worth checking... from what I can tell, those go bad from continued looser-than-should-be cam chains over the years. Mikes has them for about 35 bucks... I replaced mine when I did the top end, and now my motor is MUCH quieter and runs better.

 

[WELDFAN]

thanks guys, im gunna pull the tensioner and check what type of set up i have and look at my year spacific set up to ensure i can either go by normal setteings or if i will have to note the variation and adjust accordingly

 

[WELDFAN]

i been out of the loop i know for a while but i focused on my new home and on my mini bike racing... which we just did an ice race on frozen lake which was worth the time and effort to rebuild and pay attention to my mini

 

[WELDFAN]

so i have a new problem i will maybe start a thread on if i dont find one tackling the issue, which is... a stripped thread on a valve cover

 

[WELDFAN]

also me and my buddy picked up another xs and soon i will be doing a complete engine rebuild that i hope to record on here

 

[WELDFAN]

the newest addition sitting next to terry, cant wait to do a motor rebuild so terry can live again

 

[WELDFAN]

my first un exspected set back on getting the issue with my xs fixed was when i pulled the valve covers to check gapping i found one post had striped out and is in need of repair so i picked up a helicoil kit and will be fixing it this week

 

[WELDFAN]