Bushyboy's build thread

[Bushyeyed1]

I found the source of my leak and I'm not very happy about it. It turns out the exhaust valve keeper adjustment screw inadvertently came off and the cam must have smashed it into the head which resulted in a crack in the head. I am assuming all year model heads will swap?

 

[650Skull]

72 and on i think.........the earlier 70/71 have some differences............74 and later is a sure bet.

I have heard stories of the tappet threads stretching and this can be a cause for the nuts loosening......of course if they haven't been tightened properly ........... they can be a bit of a bitch if the right tools aren't used

 

[650Skull]

Have to buy the head and rocker cover as a set.........They are line bored together and numbered as a matching set.....If your real lucky another rocker or head will match near enough for them not to leak but there can quite big differences that they will leak around the cam seals.

 

[Bushyeyed1]

Trying to hunt the good stuff and think happy thoughts drinking my coffee this am. A recent gremilin attack has set me back on my project. Going to change out the pans on this seat to keep it oemish and probably figure out something with the chrome strip not to be installed. What y'all think about the seat?

 

[Paul Sutton]

My view is not Universal, I'd go for the seat that allows me to sit comfortably. Depending on how tall you are or length of arms and the style of handlebars you may need to sit farther forward or farther back. If you want the cafe look then you know which seat to go for. That other seat does look very nice if you want a more standard look, but make sure the change in level region allows you to sit comfortably. I find the stock seat on my SH pushes me too far forward, but makes sitting easier at higher speeds as it locks my butt in position against the air resistance with rototiller bars.

 

[Bushyeyed1]

Paul Sutton it may be the years of riding dirtbikes but I tend to sit forward on the seat. I may shave down the hump on the back just a tad to give it a slimmer look.

 

[Bushyeyed1]

A hang test

 

[Bushyeyed1]

So I got a question for the experts. My used head is coming in and I wonder what the recommendations are for maintence while I am in there. I already have engine gasket seal o-ring set so as long as I can get to it then it will be replaced. My question is more geared toward mechanicals like Cam chain, guide, springs ect.

 

[5twins]

First time in one of these, I usually replace the cam chain, the front cam chain guide, and the valve guide seals for sure. I check the valves for leaks and hand lap any back in that do. Bores and pistons are checked for wear, and if still within the wear limits, ring end gaps are checked. These are usually found to be too big so new rings are fitted. Of the probably half dozen or so of these I've been into, I only found in-spec rings in one, the rest were worn. If the bores and pistons are worn beyond the specs, a re-bore will be needed.

Reasonably priced rings and over size piston sets are now available from eBay seller cruzinimage .....

https://www.ebay.com/sch/m.html?_ss...10.TRC2.A0.H0.Xxs650.TRS2&_nkw=xs650&_sacat=0

 

[Paul Sutton]

Regarding your oil leak: I wonder if this was due to the Cam bearings not being set far enough in. What surprised me with the XS engine is how the pairs of cham bearings do not sit well by my way of thinking - the inner most bearing of each pair is not fully supported by the head and rocker cover. About 1/3 of this bearing is left hanging in the air. If the bearings are positioned to be fully supported then once you torque the head down you will not be able to get the alloy breaker covers with their oil seal, o-ring and paper gasket to screw fully in and seal.

What I did was put the bearings roughly in place and place the rocker cover on top. Then push the breaker covers into place to push the the bearings into the correct position. I then removed the breaker covers and torqued the head down.

Edit: This method of locating the cam and bearings in incorrect. See Entry 72 for comments by XSLeo.

This was my approach, but I am sure there are many other ways to skin this cat. I also considered positioning the bearings by using calipers to set the depth that the breaker cover needed to be inserted.

Also...

If the cam is not centered the oil seal in the breaker cover may not make a good contact with the cam. This was an issue for me and is further complicated by the thickness of the oil seal you use. There is a thread somewhere where it is noted that the oil seals on the market are 5mm, 6mm or 7mm in thickness which also has an impact on sealing ability. I am not sure as to what the best seal thickness to date is?

 

[Bushyeyed1]

@Paul Sutton that is good advice, but this little bugger is what vibrated lose. I would take a picture of the crack in the block if I were able to.

 

[Paul Sutton]

That little bugger is one big hardened BUGGER. It's a lash screw. I just couldn't see how a little valve keeper would do the damage. Best of luck with the next phase.

 

[Bushyeyed1]

Yeah I guess I did say keeper but meant the adjusting screw. Sorry for the confusion, but by the look on the inside the Cam lifter smashed it into the head. Fingers crossed the Cam is still good.

 

[Bushyeyed1]

Step 1... Check
I meant to break torque on the head before pulling it off the mounts but oh well. I didn't have as much trouble as I was expecting lifting engine out. I set up a bike stand on right side with a few pieces of wood to ensure engine wasn't sitting on the nuts underneath. Then I took a car jack to lift engine slightly. Then in one swift motion rocked right and picked up only having to lift few inches. Worked pretty smooth and I lifted with my knees.

 

[Bushyeyed1]

She looked cold without an engine so I pulled the top off. With the head off you can see the damage from the adjustment screw. The Cam lifters only have a few scratches but nothing deep so I think I'll call the Cam good. Patiently waiting for my Fedex shipment.

 

[Bushyeyed1]

Oh she sure purrrrrrs like a kitten with those new pipes. No leaks and everything appears to be in order. Too bad it is 20 degrees or I'd take her for a ride. I would have taken more time with the engine rebuild, but had to get it operable. Long story short the NC sheriff office had come out to check my vin so I could get my title since its an antique. One thing he failed to mention was it had to be running. I told him if he had come three days ago; or for that matter within the two or three months I had been waiting on him to come, then I could have fired it up.

 

[Bushyeyed1]

A few updates to the build; it was warm so I took her for a spin. Ran great and sounded fast, but looked down and was only going 40 mph. Got the fabrications done for use of side mount on the seat pan. Added a Relay for my next project of adding led turn signals. So I need to finish the seat and start working on headlight, tail light, and turn signals. A little tweaking here and there and some warm weather and she will be on the road.

 

[Bushyeyed1]

Pulled her out in the sun for a quick photo shoot. Of course this was before my dog jumped on me and I fricken knocked her over bending the brake lever a little. Two steps forward one step back. I'll get the touch one day I guess

 

[650Skull]

Nice..............Looks like you need some rain.........you can have some of ours, it literally hasn't stopped raining every day for 2 months for any longer than a couple of days, and that has only been a couple of times...........at least you don't have to mow lawns

 

[Bushyeyed1]

Nice..............Looks like you need some rain.........you can have some of ours, it literally hasn't stopped raining every day for 2 months for any longer than a couple of days, and that has only been a couple of times...........at least you don't have to mow lawns

Thanks; we have been getting rain here, but it is winter and since the soil is kinda sandy it always turns brown from fall until spring. Could be lucky I haven't had to pull out the old mower in a while, but I probably could rake some leaves.