Top End Rebuild

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VCPatel

XS650 Enthusiast
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Friends,

I have a base gasket leak on my XS650 and plan on rebuilding the top end next week. I plan on buying the necessary parts today.

Since I don't plan on pulling the engine again for some time, I want to make sure I capitalize on the fact that it'll be out and apart.

Any tips and suggestions for things I should be sure to do while I go through the engine next week? I don't want to leave any stones unturned while the engine's out. Any parts I should be sure to buy and replace? I want to place the order later today, so any suggestions would be great.

As it stands I am thinking about doing the full gasket shebang, and replacing the rubber washers on the top bolts with the copper washers from mikesxs. Also want to change the piston rings while I can.

Anything else I'm missing?

Also, for viewing pleasure: picked up this little one-banger (Kawasaki KZ250 CSR) for $500 to get me around while the XS is down:


... and one with the XS:

Fun little bike-- really very nice around town.

Thanks,
VCP
 
If you have 15 to 20K or more on the 650, I would replace the cam chain. I would replace the front cam chain guide no matter what the miles just because of it's age. Elephant foot valve adjuster screws are a nice mod too but take a bit of work (grinding the rockers).
 
Yes, I do. You need to remove about 4mm from the bottom of the rocker so the "foot" will clear .....

ElephantsFootandStock.jpg


It's pretty easy to do. I did mine on a bench grinder, dipping the rocker in a cup of water when it became too hot to hold.
 
Deff do the front guide. The cam chain is a good idea, Also check your sump filter and replace with the reinforced one if you have not done so already. If you need a set of rings I have a set I'll sell for 40 shipped. I got them from mikes but had to do and over bore.
 
Thanks everyone, some good cheap fixes I missed. I think the front guide is a good call, as is the reinforced sump filter.

What could be the consequences of holding off on the cam-chain until the winter? Is it just a matter of requiring more frequent adjustment? Is it more important than replacing rings? I was initially planning on pulling the engine in the winter anyway, but the blown gasket forced me to get into it now. I don't mind getting in there again this winter. I guess this is just a money issue. I'm applying to medical school-- and that shit is ridiculous expensive.

RFLIVES: Do you have rings for both pistons? I might take you up on the offer if you do.
 
Less wear on the valve stem and less noise. The original screw has a rounded end like the tip of your finger. It only contacts the valve stem in one tiny spot at any given time. Eventually, this wears a dimple into the stem top. Since the original screw contacts in one little spot, the tip of it also wears out. Pull your stock screws out and look at the ends - I bet you find at least a couple of them already worn. You can buy original style replacements but eventually, they're going to do the same thing. The elephant foot screw contacts the whole top of the valve stem so eliminates this problem.
 
Waiting to do the cam guide is a bad idea. If its to expensive to do it now, how is it cheaper to buy the gaskets and redo it again in just a couple months? Cam guides wear and rip off the material that the chain rides on and drops it to the bottom of the cases into the oil and plugs up the filter. If its worth doing, do it right the first time so you can do this:bike: and not this:banghead::doh:

Posted via Mobile
 
Ironsled77 said:
Waiting to do the cam guide is a bad idea. If its to expensive to do it now, how is it cheaper to buy the gaskets and redo it again in just a couple months? Cam guides wear and rip off the material that the chain rides on and drops it to the bottom of the cases into the oil and plugs up the filter. If its worth doing, do it right the first time so you can do this:bike: and not this:banghead::doh:

Posted via Mobile
Click to expand...

OP was asking about waiting on the cam chain...not the cam guide.
 
That's like taking a shit and not wiping your ass. Do you change your oil and not your filter? Once again you would have to buy the gaskets again to replace the cam chain. Or you can leave it and do it in the winter.:laugh:

Posted via Mobile
 
exactly....if it's apart now. do it.

would have been better not spending the 500 dollars on another bike if you can't afford to do the motor properly. or let it sit till you can afford to do it all.
 
Haha-- sheesh:yikes:-- I promise my decision making skills and rationality are in line; there were many reasons for why I purchased what I purchased and did what I did. But, as is often the case, things come up, and situations change. But, to explain all of these things would be a waste of everyone's time.

I ended up getting the cam-chain. It seems the general consensus was that the cam-chain replacement is essential to good reliable performance. Thanks very much for the help and advice-- I really do appreciate it.

But, I am still curious about the chain. Under the assumption that the cam-chain front guide is in good shape [let's say I replace it with the new one], and the cam-chain has somehow managed to stay okay over the mileage, what problems could occur if I were to keep the old chain? What would cause those problems?

Thanks again for the help everyone.

Viral
 
Not a ton if it's not that worn, but if it is if and you have points you run out of adjustment due to chain stretch, tensioner will eventually run out of adjustment and the chain slaps around and if it's that worn it can break wreaking havoc. But why use old parts if the thing is open.
 
Just finished a top on a '77D (no prior experience). Had 28K. The cam chain looked fine & had plenty of adjustment left (they are tough). I put in a new one anyway, higher miles and no history. It's a pain to pull the engine, especially if you don't have a place to work on it without breaking some rules, not to mention damage due to a break. If you do change it and haven't checked out how, look at http://www.650motorcycles.com/XStips2.html, accessing the chain through the sump works :thumbsup: great! Don't be afraid to grind or cut off the peened part of the link to separate the old chain (Dremel cutoff = done!) and don't be afraid to peen the master link on the new one, the metal is soft, I used a light hammer on a small cold chisel with the chain hanging out of the sump and backed by a sledge hammer. Easy to do, and...

You might just get your money back on the 250.

Good Luck!:bike:
 

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