Sleeve the bores? this aint a P51

[xjwmx]

I wish someone could testify to this. You would think after what, 5-6 years, watching these boards(multiple forums) we(you and I, Leo) would see someone saying "Mine has been working well for XXX miles well past the 15-20K mark".

Here's some honest truth. When I bought ol' Trigger she had 17,000 on the clock. She now has 49,000 and therefore I can state unequivocally the cam chain and guides have lasted 32,000 miles. Since there's no sign that the engine has ever been opened up, you might speculate and say the chain and guides have lasted 49,000 miles so far. I've tried to take good care of the motor and there were signs that prior to 17,000 someone else was doing that too.

The only problem is that suddenly she has started to use about maybe 1qt of oil about every 500mi. At highway rpms. The bolted on plated under the left cover worked loose and leaked some oil and I rode it like that for about 500mi at 100^F temperatures. Check your oil every time you gas up!

But she has also started to trickle oil from the head gasket, so I'm hoping a re-torque will fix her oil issue. That will probably have to wait till spring.

I would really hesitate to replace genuine yet old Yamaha innards with new Chinese copies at a certain mileage just as a matter of course.

 

[SE Road King]

Somebody wrote an amusing post about resleeving the bores. Maybe gggary. You put the cylinders in the kitchen oven and leave them there until you hear a thunk, which is the sleeves falling loose.

re: the buckhorn bars, some ppl like them. The most accurate thing to say about them is "they are hated on the internet." I had to get rid of mine because they were giving me a clinical case of rotator cuff problems. I replaced mine with same era cb750 bars which are also "hated on the internet." Much better choice, including the fact that the palms face down, giving more power to the brake lever. But similar configuration otherwise.

I wonder if that can really happen, given that the sleeve and the cast jug are heating up at the same time at nearly the same rate. I guess with luck...
I have experience in warming jugs and LiNi the sleeves to install, but to remove the liners I usually bored them 95% or so and tore them out.
Just a note: on some industrial power plants they just lift right out of the block.

 

[SE Road King]

Here's some honest truth. When I bought ol' Trigger she had 17,000 on the clock. She now has 49,000 and therefore I can state unequivocally the cam chain and guides have lasted 32,000 miles. Since there's no sign that the engine has ever been opened up, you might speculate and say the chain and guides have lasted 49,000 miles so far. I've tried to take good care of the motor and there were signs that prior to 17,000 someone else was doing that too.

The only problem is that suddenly she has started to use about maybe 1qt of oil about every 500mi. At highway rpms. The bolted on plated under the left cover worked loose and leaked some oil and I rode it like that for about 500mi at 100^F temperatures. Check your oil every time you gas up!

But she has also started to trickle oil from the head gasket, so I'm hoping a re-torque will fix her oil issue. That will probably have to wait till spring.

I would really hesitate to replace genuine yet old Yamaha innards with new Chinese copies at a certain mileage just as a matter of course.

Good News. Proper PM pays every time.

 

[xjwmx]

I wonder if that can really happen, given that the sleeve and the cast jug are heating up at the same time at nearly the same rate. I guess with luck...

Well, that is how you remove the sleeves. At some temp quite a bit higher than normal running temp there's enough difference in expansion to let them fall out.

 

[weekendrider]

xjwmx I knew you were racking up the miles. I didn't know if your cam chain was original.
When you adjust the tension do you have many threads left showing on the adjuster nut.

 

[xjwmx]

^The amount of adjuster sticking out past the lock nut is about like the pictures you see. Not a striking amount screwed in or anything.

 

[XSLeo]

The aluminum block expands at a faster rate than the steel lof the sleeves.
One guy found this out as he was baking his cylinders after painting. He put the cylinders in the oven the same side up as when on the engine. As he was doing the baking, he heard the clunk and found the cylinders had slid down off the sleeves.
He let them cool then flipped them over and cooked them until he heard another clunk as the cylinders slid back in place.
A lot of farm tractor engines have replaceable sleeves. Some are dry sleeves some wet sleeves. The dry sleeves are pressed into the block into holes simular to the regular bore, just big enough to put in the sleeves. You can bore the sleeves a few times but once you go so far you change the cleeves to start back at the stock bore. With out sleeves the engine block would have to be replaced after a few rebores. With sl;eeves the block can be used forever. A lot of these tractors the block served as the frame between the front end and the transmission/final drive cases. A very expencive part to replace.
The wet sleeves are pressed in also but the block has just a top hole and bottom hole with the area between the holes the water jacket. There are orings to seal the sleeves into the block. I have changed both styles.
With Mike's stock size bore liners the same can be done with the XS650 cylinders.
Leo

 

[jd750ace]

The aluminum casting will expand considerably more above 200 degrees than the sleeve will. The melting point of cast 356 alloy is somewhere near 1120 degrees Farenheit. The sleeve's melting point is somewhere north of 2000 degrees. At around 1/3 of it's melting point (relative to zero) the aluminum has expanded about 90% of the total it will prior to melting. On most fits like this, 250-300 degrees is plenty to expand the aluminum far enough to release.