Agent74
XS650 Member
Hi guys,
I have been benefiting immensely from all the tech. posts and discussions on this site.
Over the course of the summer I finally got to working on a 1979 XS650 SF that I had purchased in '05 or '06. It is mostly stock with the exception of some paint.
When I purchased it from my brother in law, he stated that the cam chain was rattling and probably in need of replacement. I went ahead and replaced the chain while cleaning and learning along the way. I replaced the front guide with a unit from Hoos racing (thanks to Gary) while i was in there. New head gasket went in along with copper washers for the top end and a replacement cap nut for the chain adjuster as the old one was missing the o-ring. The front brake reservoir had leaked fluid from the big o-ring at the base of the nylon cup, so that got replaced along with repainting the metal housing and brake lever. I rebuilt/repainted the the front brakes as well as fluid had seeped through the piston seal. The carbs got a cleaning and kit, new air to carb gaskets.
That covers most of my adventures in repair/rebuilding so far.
The issues left to deal with now are #1. After the first reassemble I could not get it to fire. After a couple of days trying everything else I finally listened to Bro in laws' first suggestion of switching the spark wires which solved it (started on the second kick). It did have a lot of lag/rough running in the first bit of throttle twist, but would idle like a dream. Moved the clip on the needle from slot 3 to second from bottom and that seemed to help. I hope it's not too rich.
#2. the timing has gone out after my first ride. When I took off the tensioner cap nut I noticed that it had moved in from flush by about 3-4mm. Is the chain able to jump a tooth with just that amount of slack? I think it was running hot too, judging from the color of the spark plugs (not to mention the smoke coming off the engine after getting it back to the garage).
That's enough for now I think.
I have been benefiting immensely from all the tech. posts and discussions on this site.
Over the course of the summer I finally got to working on a 1979 XS650 SF that I had purchased in '05 or '06. It is mostly stock with the exception of some paint.
When I purchased it from my brother in law, he stated that the cam chain was rattling and probably in need of replacement. I went ahead and replaced the chain while cleaning and learning along the way. I replaced the front guide with a unit from Hoos racing (thanks to Gary) while i was in there. New head gasket went in along with copper washers for the top end and a replacement cap nut for the chain adjuster as the old one was missing the o-ring. The front brake reservoir had leaked fluid from the big o-ring at the base of the nylon cup, so that got replaced along with repainting the metal housing and brake lever. I rebuilt/repainted the the front brakes as well as fluid had seeped through the piston seal. The carbs got a cleaning and kit, new air to carb gaskets.
That covers most of my adventures in repair/rebuilding so far.
The issues left to deal with now are #1. After the first reassemble I could not get it to fire. After a couple of days trying everything else I finally listened to Bro in laws' first suggestion of switching the spark wires which solved it (started on the second kick). It did have a lot of lag/rough running in the first bit of throttle twist, but would idle like a dream. Moved the clip on the needle from slot 3 to second from bottom and that seemed to help. I hope it's not too rich.
#2. the timing has gone out after my first ride. When I took off the tensioner cap nut I noticed that it had moved in from flush by about 3-4mm. Is the chain able to jump a tooth with just that amount of slack? I think it was running hot too, judging from the color of the spark plugs (not to mention the smoke coming off the engine after getting it back to the garage).
That's enough for now I think.
