alfredo
1978 xs650 Special
I know its too late, but the valve stem seals come with the athena gasket kit.
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My '80 xs650 engine rebuild
- Thread starter sseres
- Start date
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- Tags
- build engine pictures restoration
sseres
XS650 Junkie
Thanks!
shoot me a PM if you have any particular questions about things I didn't picture. I've tried to be pretty detailed in my documentation and save some of the more mundane stuff from the board.
sseres
XS650 Junkie
OH HELL! Well, I'll try to sell them here or something. I wish there was a menu from which you could order rebuilt kits for redoing a complete engine to make it easier not to double order things you don't need. live and learn,.
sseres
XS650 Junkie
just a Luddite mistake. That's all. I want nothing more.
sseres
XS650 Junkie
little update: got the cam guide from UK today! just waiting on my big box from Mikes. Got the rake for my buffer wheel and will keep working on that. Took the valve cover to a machine shop a friend referred me to (which is right across the street from a motorcycle shop). man... if I could be let loose in there.
Anyway, it's interesting... his opinion on lapping valves. He drew a little picture and talked angles and blah blah about how lapping is old school because he can grind all 4 for $75. I know it won't cost me that to lap, but if I am trying to get the compression back up and the pistons and cams are pretty good shape (I will get them measured) is it worth getting them ground while I've got the whole thing apart?
Anyway, it's interesting... his opinion on lapping valves. He drew a little picture and talked angles and blah blah about how lapping is old school because he can grind all 4 for $75. I know it won't cost me that to lap, but if I am trying to get the compression back up and the pistons and cams are pretty good shape (I will get them measured) is it worth getting them ground while I've got the whole thing apart?
He just wants your $75. You still lap a little bit with fine compound after grinding to get the final finish. As far as those angles go, you already have what's called a 3-angle valve job, it came that way from the factory. There's a high performance 5-angle valve job but apparently they aren't of much benefit to our old twins.
Usually you have a valve ground if it's really, really badly pitted, so much so that simple hand lapping won't fix it or just take forever. Many times, seats are cut, not ground. That's where the angles are. The seat is considered one of the angles and the approaches on either side the other two. The seat should be a specified width to properly seal and transfer heat from the valve to the head. Sometimes through wear or too much lapping, they get too wide. Then one or both of the approach angles need to be cut to narrow the seat back down again.
Usually you have a valve ground if it's really, really badly pitted, so much so that simple hand lapping won't fix it or just take forever. Many times, seats are cut, not ground. That's where the angles are. The seat is considered one of the angles and the approaches on either side the other two. The seat should be a specified width to properly seal and transfer heat from the valve to the head. Sometimes through wear or too much lapping, they get too wide. Then one or both of the approach angles need to be cut to narrow the seat back down again.
sseres
XS650 Junkie
I figured as much. Lap myself, I shall! Actually, the valves look very clean and hardly have any carbon on them.
sseres
XS650 Junkie
Bummer.
Took the cylinders and pistons in and the machinist showed me that one of them had gone out of shape and rubbed against the cylinder wall. Gave him the measurements and he'll be getting back to me to see what needs to be done with regard to boring. He said they'll do it and hone for $150. Now I need to buy 2 new pistons (can't just replace 1) which run $54 at Mikesxs for a kit with the pin and clips. NUTS. But at least I guess I now know what caused the low compression.
On a more exciting note, seeing the head they'd already glass beaded and put a clear coat finish thing on looked amazing. I'm going to keep the whole thing that unfinished aluminium finish.
Side covers will be mirror finished, at least to the best of my ability.
Oh, also on the valve cutting cost, I was wrong. He told me that he would do the whole head, AND cut the valves (and check to make sure they don't leak) for $75, not just the valve cutting for $75.
Took the cylinders and pistons in and the machinist showed me that one of them had gone out of shape and rubbed against the cylinder wall. Gave him the measurements and he'll be getting back to me to see what needs to be done with regard to boring. He said they'll do it and hone for $150. Now I need to buy 2 new pistons (can't just replace 1) which run $54 at Mikesxs for a kit with the pin and clips. NUTS. But at least I guess I now know what caused the low compression.
On a more exciting note, seeing the head they'd already glass beaded and put a clear coat finish thing on looked amazing. I'm going to keep the whole thing that unfinished aluminium finish.
Side covers will be mirror finished, at least to the best of my ability.
Oh, also on the valve cutting cost, I was wrong. He told me that he would do the whole head, AND cut the valves (and check to make sure they don't leak) for $75, not just the valve cutting for $75.
alfredo
1978 xs650 Special
Great update and keep your head up. I'm excited to see the video of this thing firing soon!
sseres
XS650 Junkie
Got my parts back!! Ok, for those keeping track, I sunk $150 into having all these glass beaded and a clear coat applied, INCLUDING the valves ground, cleaned. I can't believe how amazing these parts look.
I left the jugs at the machinist as it needs the bore. 1st size overbore pistons and rings just ordered from Mikes and should be here sometime next week!
I left the jugs at the machinist as it needs the bore. 1st size overbore pistons and rings just ordered from Mikes and should be here sometime next week!
pythonregius24
XS650 Addict
looks good! keep it up!
sseres
XS650 Junkie
how fun is this? Daughter Lucy and I got started on reassembly while I'm waiting for my new pistons to come in from Mikes.
First question. this is the starter gear. Should it look this worn? It's pretty symmetrically rounded at every tooth, so something tells me it just might, but I don't have a close up to refer to. Does it need to be replaced?
Next question has to do with the gears that transfer torque from the starting engine to the crank. They fit on "shaft 1" and as far as I can tell, it's just a sort of fit together. No circlips, no nothing. Anyway, my question is that it seems this shaft can wiggle in and out about 1/4" in the crank case, AND the little gear has obvious play in it (see pictures showing both position). Is this right?
This is the big gear showing how there's play:
here's the small one with play in the shaft:
One more thing... how easy should it be to turn the starter gear assembly when it's all oiled up?
First question. this is the starter gear. Should it look this worn? It's pretty symmetrically rounded at every tooth, so something tells me it just might, but I don't have a close up to refer to. Does it need to be replaced?
Next question has to do with the gears that transfer torque from the starting engine to the crank. They fit on "shaft 1" and as far as I can tell, it's just a sort of fit together. No circlips, no nothing. Anyway, my question is that it seems this shaft can wiggle in and out about 1/4" in the crank case, AND the little gear has obvious play in it (see pictures showing both position). Is this right?
This is the big gear showing how there's play:
here's the small one with play in the shaft:
One more thing... how easy should it be to turn the starter gear assembly when it's all oiled up?
The worn gear is your #4 starter gear. It may still work OK but you'll need to bend the drag clip tight again. It's loosened up and that's why the gear was grinding (and wearing). Instructions are here .....
http://en.650wiki.org/index.php/12.08._Electric_start_problem_fix
http://en.650wiki.org/index.php/12.08._Electric_start_problem_fix
Hoperator
book stains on motor oil
suuuuuuubscription!
mustangpalmer1911
XS650 Enthusiast
Going to be one useful thread in a couple months!
sseres
XS650 Junkie
Excellent, thaks as always. Just to be sure, we're talking about the funny shaped clip with the approximately 1/4" loop in it? I'm not sure why it is if that puppy squeezes #4 tighter thatll engage the gear better... So that's why I want tobe sure I get what part needs to be retightened.
sseres
XS650 Junkie
duplicate
Last edited:
Mister Mellow
Big Dreams, Thin Wallet
pythonregius24
XS650 Addict
what did you use to break the master chain?
