Ready for Top End Rebuild

Arclight88

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First time doing a ring job and valve lap and I am getting the parts together.

Rings arrived last night (Yamaha genuine parts). The package has several rings in it. I understand that some are different, and I can tell by looking at the piston where they seem to go.

Questions:

Some of the rings have an "N" stamped on one side. I presume that means something like "North" for this side up on installation. Is that right?

The thinner rings have no stamping, so I presume they are not oriented on install. Is that right?

Also, there are more little rings than are presently on my pistons. Should I install all that were in package, or faithfully replicate current installation, or something else?

And of course, I will check the end gap on all rings prior to bolting things down. And I have a ring plier to ease fitment. And I will use lots of oil.

Any other thoughts?

Thanks.
 
the N denotes that this is the top of the ring because they a very slightly shaped at an angle which touch the cylinder wall. they scrape the oil back down the into the crank not up into the combustion chamber.

you need to make sure that you put the right rings in the right place!

the ring gaps need to be placed at specific angles around the piston. the manual will tell where the gaps are.
 
My ring expander tool worked great removing old rings and stopped working right installing new ones, i.e. twisting, very cheap tool. Maybe I stepped on it,ha. I found it worked just as well to do it by hand very carefully.
All stampings must face up.
More rings than you had? Did you order them by part # for your bike? From a dealer? Double check that maybe.
 
the oil control ring consists of a thin ring, the wavy washer and another thin ring. I presume that's what ArcL was referring to!
 
I am into it now. Top end is apart with no surprises. The head gasket appears OK with no burn marks or discoloration. I presume that the left cylinder low pressure and oil burning is from poor rings after 20,935 miles.

Some pictures: First two show the head after 1) five minutes of brass brush work and 2) the complete interior head clean-up. Next I will lap the valves, check valve measures and spring lengths, and replace the valve stem seals.

Picture three shows the front view of the cylinder block. Notice the light shinning throught the middle? This is because it is clean. I was cleaning up around the block and noticed my pick just kept diving in the spaces and removing over 30 years worth of sand, mud, and oil! :eek:

It's clean now, but I did not know that space was designed in. Good idea to keep this clean to help engine cooling. What a sheltered life I've lead!
 

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Nice job; it looks very clean. The "vent holes" between my jugs (lol) were also totally blocked before I tore it down!
 
nice job on the head! upload more photos of the rebuild progress, im going to be doing mine soon this will be very useful to see photos of your rebuild.:thumbsup:
 
nice job on the head! upload more photos of the rebuild progress, im going to be doing mine soon this will be very useful to see photos of your rebuild.:thumbsup:

More build time today.

Lapped the valves - that was more fun than I thought it would be.

The valve stem caps are press fit. I used a screwdriver handle to press them on (easy enough). Be sure to slide the valve spring base seats over the valve stems before you install the stem caps!

The rest of the valve install goes extactly like the manual depicts.

I decided to repaint the engine block. Taped it up and hit it with high temp flat black. Then I buffed the edges.
 

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Haha, I see you initially jumped the gun on those valve stem seals. You are doing some fine work!
 
I've run into a snag and I need some advice.

Put the rings on the pistons, checked the end gap and they were in tollerance. Put pistons on rods, put cylinders on to pistons, used lots of oil, and the pistons seemed very tight in the cylinders. Just to recap, the cylinder block was honed.

By the way, I sorted out my misunderstanding of how many rings are on each piston, I now apprciate how the oil ring(s) are assembled.

It took a good deal of gentle tapping on the block head with a dead fall hammer to move it down over the pistons and into the motor base.

Torqued down the head and proceeded to try turn the crank to LT for cam install, and ran into a problem. The crank will not turn. I followed the direction of putting a wrench of the bolt head on the generator house to turn the crank counter clockwise, and all that happened was the bolt came loose (oh crap!)

I checked the timing chain and it is free and not bound up down in the block.

So I tightend the bolt back and stopped that approach. When I tightend that bolt the crank did not turn clockwise either. I thought about the kick starter, and when I tried it, the crank will not turn at all, not even a fraction of an inch (wax pen mark on the timing cover did not move.) So I stopped trying the kick starter and decided to ask all of you.

I suspect that I will need to remove the head and cylinder block, to address this issue, but I do not know what the error is or how to fix it.

Anybody ever have this happen? Any thoughts?
 
Hi arclight, someone here will have an answer. Im new to top ends rebuilds and in the process of doing my first one so all i can do is speculate. Is it possible the hone guy honed it just that fraction too tight? Were all the rings seated properly? Maybe its jammed up somewhere else somehow and its unrelated to the pistons and bore? Thats all i can think of, dont worry though you will sort it once others drops by with more experience:thumbsup:
 
Are the pistons in the same side of the jugs they where to begin with and facing the right way?
 
Are the pistons in the same side of the jugs they where to begin with and facing the right way?

Thanks for the response and those are good questions.

Yes, the pistons are in the same jugs as they started.

The pictures included here depict that the arrows are pointing forward.

I used motor oil to assemble the motor. A website help line for this issues suggests I use STP as an assembly lube (which I might try next.)

I honed the cylinders myself and followed the directions on the packages. There was not a ridge ground into the cylinders prior to renewal, just oil residue at the top of the cylinders. Prior to honing, there was practically no cross hatch pattern on the cylinder walls, but honing gave a nicely 'hatched' finish.

The engine status right now is as indicated, left piston is at bottom and right is at top of cylinder, and I cannot get the crank to turn at all.

Does anyone know the correct torque to apply to the crank shaft generator bolt?
 

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22-25 lbs ft.:thumbsup:

OK, Chris, thanks for that.

What I will do is torque that bolt down, then remove the head, and then the cylinders.

Then I will remove the pistons, and reclean the piston ring grooves, recheck the gaps for the maximum gap value, and reassemble with STP.

We are probably about 6-hours from me starting this effort, so if anyone has any tactics, techniques, or proceedures to augment this plan, I would appreciate their input.

Thanks,

DJ
 
something's not right here. you either got something jammed (have you done the timing right and are not hitting a valve?) or a ring has twisted (looking at the pictures, they are in at an angle)
honing loosens the bore not tighten it.

take it all off, check if the pistons move without the head on, then recheck the rings and put the barrel on. check the pistons move before you put the head back on
 
something's not right here. you either got something jammed (have you done the timing right and are not hitting a valve?) or a ring has twisted (looking at the pictures, they are in at an angle)
honing loosens the bore not tighten it.

take it all off, check if the pistons move without the head on, then recheck the rings and put the barrel on. check the pistons move before you put the head back on

Hi Drewp,

Since I never made it to the valve cover install, I presume I am not hitting hitting a valve.

The twisted ring theory make sense, I will see what I find.

Thanks,

DJ
 
Hi Drewp,

Since I never made it to the valve cover install, I presume I am not hitting hitting a valve.

The twisted ring theory make sense, I will see what I find.

Thanks,

DJ

did you overlap the valve chain at the crank end?, that will jam it up
 
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