Don't look like it needs no "casket set"!!!! To me.
Great work JD.
Great work JD.
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XS1B Engine Teardown
- Thread starter Jim
- Start date
Rut-row, Booboo...
The head soaked long enough take it apart. This ain't gonna buff out.
Yeah, the stem of the intake valve has been beaten into a mushroom. Had to take the Dremel to it before it'd pull out of the guide.
Luckily, I keep spares...
Just preliminary, but the guides feel nice and tight. I'll give 'em a proper check when it's all cleaned up, but I expect they'll be fine. Same with the seats. No corrosion pits to speak of, they should lap in just fine without recutting. Again with the disclaimer... this damn Pixel magnifies everything. The little bit of pitting you're seeing in the pic is pretty much non-existent to the naked eye. Worst case, I know a guy with the right size seat cutters iff'n I need 'em.
You can see the remnants of a plug in one plug hole in the last pic. Was like that when I got it.... so at least a decade of rusting itself in place. Might just have to drill it out, but I'll let some more P B Blaster soak into it for a while longer before I get drastic with it.
Also have a bent stud on an exhaust port. Gonna replace all 4 I think.
Does anyone know from all the testing done here which elephant foot adjusters are the best fit for these engines??
The head soaked long enough take it apart. This ain't gonna buff out.
Yeah, the stem of the intake valve has been beaten into a mushroom. Had to take the Dremel to it before it'd pull out of the guide.
Luckily, I keep spares...
Just preliminary, but the guides feel nice and tight. I'll give 'em a proper check when it's all cleaned up, but I expect they'll be fine. Same with the seats. No corrosion pits to speak of, they should lap in just fine without recutting. Again with the disclaimer... this damn Pixel magnifies everything. The little bit of pitting you're seeing in the pic is pretty much non-existent to the naked eye. Worst case, I know a guy with the right size seat cutters iff'n I need 'em.
You can see the remnants of a plug in one plug hole in the last pic. Was like that when I got it.... so at least a decade of rusting itself in place. Might just have to drill it out, but I'll let some more P B Blaster soak into it for a while longer before I get drastic with it.
Also have a bent stud on an exhaust port. Gonna replace all 4 I think.
Does anyone know from all the testing done here which elephant foot adjusters are the best fit for these engines??
Since you have this in front of you, do the plug threads change from aluminum to iron part way down? 
Yup. Going from inside the head outwards, about the first 2-3 threads are in the steel or iron dome. The rest, going out, is about 8-10 threads in the aluminum head casting.Since you have this in front of you, do the plug threads change from aluminum to iron part way down?
Thank You for this Inspiring.
Any signs inside motor why it was parked ..?
I can se a wooden engine holder on the bench .That is something I will look into .I have a workbench to build I have the legs 2 inch pipes and other
steel and the top planks as well .Just need to get the Stick welder out and do it.
I also have a set of engine cases that I will try to paint .Small compressor but I can try -- Is it difficult paint.
When it comes to restrictions It is a science in itself Often a trial and error activity In Air condition and Hydraulics.
It is the system and the Pump ( or fan )
A fixed displacement pump will deliver the same Flow regardless of the system But many Hydraulic pumps and Fans don't
So if you put in a restriction in one branch of system the flow ( out from pump ..fixed ) is the same but with higher Pressure .
If you close the flow Big chunks of metal starts flying as after an explosion .. Seen that in Excavators.
So there is a safety bypass valve.
In a Air condition system with multiple branches Restricting one branch can make the flow increase in the Other branch
And at the same time affect what the fan delivers. Fancurves
top right the sys --system curve these curves cross at the operating point
It was a process of adjusting at upstart
say for ex 3 branches one had to measure total flow in each branch and adjust distribution via
Maybe Volume Control damper in English and downstream at more of those.
Did not want to many of those Costs / Losses / And risk needing rev up the fan affecting energy costs.
So what have the XS 650 designer done reducing there Everything else the same .Less flow Oil to the top
Why would that be a good idea ?. Unless more oil is needed elsewhere. Or problems in the return flow
feel free correct me if wrong
Any signs inside motor why it was parked ..?
I can se a wooden engine holder on the bench .That is something I will look into .I have a workbench to build I have the legs 2 inch pipes and other
steel and the top planks as well .Just need to get the Stick welder out and do it.
I also have a set of engine cases that I will try to paint .Small compressor but I can try -- Is it difficult paint.
When it comes to restrictions It is a science in itself Often a trial and error activity In Air condition and Hydraulics.
It is the system and the Pump ( or fan )
A fixed displacement pump will deliver the same Flow regardless of the system But many Hydraulic pumps and Fans don't
So if you put in a restriction in one branch of system the flow ( out from pump ..fixed ) is the same but with higher Pressure .
If you close the flow Big chunks of metal starts flying as after an explosion .. Seen that in Excavators.
So there is a safety bypass valve.
In a Air condition system with multiple branches Restricting one branch can make the flow increase in the Other branch
And at the same time affect what the fan delivers. Fancurves
top right the sys --system curve these curves cross at the operating point
It was a process of adjusting at upstart
say for ex 3 branches one had to measure total flow in each branch and adjust distribution via
Maybe Volume Control damper in English and downstream at more of those.
Did not want to many of those Costs / Losses / And risk needing rev up the fan affecting energy costs.
So what have the XS 650 designer done reducing there Everything else the same .Less flow Oil to the top
Why would that be a good idea ?. Unless more oil is needed elsewhere. Or problems in the return flow
feel free correct me if wrong
The newer style valve covers with the o-ring groove in 'em seal much better than the gasket type... they just do. figured I'd chuck these covers off this engine up in the lathe and groove 'em. So I asked @gggGary if he still had the red o-rings he was sellin'.
Gary sez, "hold my beer."
Mailman jus' delivered 4 new o-rings and 4 freshly cut valve covers. You're a prince among men, Gary!!
Gary sez, "hold my beer."
Mailman jus' delivered 4 new o-rings and 4 freshly cut valve covers. You're a prince among men, Gary!!
Sue decided I didn't have enough bikes. Early Fathers Day gift.... 
Jim is such a prince I just handed him some I had bought on Amazon for my own bikes.....
uxcell 10 Pcs Flexible Silicone O Ring Seal Sealing Gasket 62mm x 68mm x 3mm
Fresh rewound rotor for a freshened up motor. Not torqued yet.
Just need to torque the case studs, install the sump screen and I can flip this thing to work on the top end. I've got the stand I made for the SG's motor but it's tied up on the run stand. Guess I need to make another.
Cut the sides out with the plasma torch.
Cut the sides out with the plasma torch.
Bottom end studs torqued to 15 ft-lbs.
Sump plate got the backyard resurfacing, installed the screen, torqued to 85 in-lbs and safetied.
Sump plate torqued to 85 in-lbs.
Before the sump plate got installed, had to set the cam chain in place. The chain is for a Kawasaki engine. It's too long, but half the cost of Yamaha's chain ( thanks for the tip @DogBunny ). Cut the chain to length. You can see when laid side by side that the original had stretched about a half a link. I could have just reused it. Unfortunately the only way to tell is to lay it beside the original. Only way to do that is buy a new one.
Both case drain plugs installed with new copper crush washers and torqued to 32 ft-lbs.
You can see the engine stand I made is installed in the pic above and below.
... and finally rolled the sucker upright, ready for the top.
I absolutely trashed the bench in the process. First order of business tomorrow will be cleanup and reorganize.
Sump plate got the backyard resurfacing, installed the screen, torqued to 85 in-lbs and safetied.
Sump plate torqued to 85 in-lbs.
Before the sump plate got installed, had to set the cam chain in place. The chain is for a Kawasaki engine. It's too long, but half the cost of Yamaha's chain ( thanks for the tip @DogBunny ). Cut the chain to length. You can see when laid side by side that the original had stretched about a half a link. I could have just reused it. Unfortunately the only way to tell is to lay it beside the original. Only way to do that is buy a new one.
Both case drain plugs installed with new copper crush washers and torqued to 32 ft-lbs.
You can see the engine stand I made is installed in the pic above and below.
... and finally rolled the sucker upright, ready for the top.
I absolutely trashed the bench in the process. First order of business tomorrow will be cleanup and reorganize.
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Yamaha made an aluminum oil stick... and then painted it...
No self respecting XS motor is gonna run around with a painted dipstick.
New cork seal, and little polish and here we are...
No self respecting XS motor is gonna run around with a painted dipstick.
New cork seal, and little polish and here we are...
I for one am glad you didn't post any pics of you polishing your dipstick.
Yep, it just needs to be a BF05T of at least 104(?) links and made in Japan. The Kawasaki fits the bill perfectly.
Cleaned up the jugs. What a mess!! Multiple rounds of degreaser, bead blaster and solvent tank. Came up nice and clean in the end. Went ahead and refaced the deck and gave the bores a 60° hone job. There's a few very minor score marks... about what you'd expect from a low milage engine. Nothing to worry about. And no corrosion pits in sight.... not a one.
Went ahead and mic'd 'em out.
Left averages out to...... 2.9533"
Right averages out to.. 2.9532"
**Tolerance is from 2.9528" to 2.9536"**
Both piston skirts measure 2.950"
Left piston skirt clearance is...... .0033"
Right piston skirt clearance is.. .0032"
The book calls for a skirt clearance between .002" and .0022.
Common practice 'round these parts is anything between .002" and .004" is acceptable. I'm more than happy with these. Now that I know the bore and pistons are good, I'll get some standard rings on order from Cruzinimage. Fingers crossed, the rings should be the last bits to buy.
And just to double check my numbers, I used the feeler gauge method on the skirts. Both were a very tight .003"
Went ahead and mic'd 'em out.
Left averages out to...... 2.9533"
Right averages out to.. 2.9532"
**Tolerance is from 2.9528" to 2.9536"**
Both piston skirts measure 2.950"
Left piston skirt clearance is...... .0033"
Right piston skirt clearance is.. .0032"
The book calls for a skirt clearance between .002" and .0022.
Common practice 'round these parts is anything between .002" and .004" is acceptable. I'm more than happy with these. Now that I know the bore and pistons are good, I'll get some standard rings on order from Cruzinimage. Fingers crossed, the rings should be the last bits to buy.
And just to double check my numbers, I used the feeler gauge method on the skirts. Both were a very tight .003"
