Time for a new jug....

[gary55]

If you can't fix yours you might as well do the whole top end while you have it torn down. At least that's what I would do. Here is about the best price I've seen for a complete top end that fits your engine..https://www.ebay.com/itm/47mm-66cc-...:BqoAAOSwKrhVXjgx:sc:USPSPriority!86303!US!-1

 

[Neo_Epoch]

If you can't fix yours you might as well do the whole top end while you have it torn down. At least that's what I would do. Here is about the best price I've seen for a complete top end that fits your engine..https://www.ebay.com/itm/47mm-66cc-...:BqoAAOSwKrhVXjgx:sc:USPSPriority!86303!US!-1

Cool beans, thanks for the heads up on the top end rebuild.

Another thing I had seen about my setup, is that it's ~38mm stroke and goes to just a hair shy under the top of the cylinder when tdc - which now makes sense to me the need for the slant head. I was wondering if I should shave down a bit of the top of the cylinder to tighten the squish closer to the head

 

[FurryOnTheInside]

Cool beans, thanks for the heads up on the top end rebuild.

Another thing I had seen about my setup, is that it's ~38mm stroke and goes to just a hair shy under the top of the cylinder when tdc - which now makes sense to me the need for the slant head. I was wondering if I should shave down a bit of the top of the cylinder to tighten the squish closer to the head

You can only figure that out by measuring the squish gap (squashing some soft solder), using the head you intend to run.

 

[gary55]

Cool beans, thanks for the heads up on the top end rebuild.

Another thing I had seen about my setup, is that it's ~38mm stroke and goes to just a hair shy under the top of the cylinder when tdc - which now makes sense to me the need for the slant head. I was wondering if I should shave down a bit of the top of the cylinder to tighten the squish closer to the head

If you measure the inside of the crush ring that seals the head gasket you'll see that on the stock slant head it hangs quite a way inside the cylinder. The ideal is to have it even with the cylinder like the after market head. Still you can remove a little off most jugs but I wouldn't suggest going under .7mm of squish gap which can be measured with rosin core 1/16" solder on top of the piston. If your not opening up the stock heads crush ring ID to 47mm make sure the solder is wall to wall so you get a measurement at it's smallest point.View media item 61116View media item 61115View media item 60815

 

[gary55]

Cool beans, thanks for the heads up on the top end rebuild.

Another thing I had seen about my setup, is that it's ~38mm stroke and goes to just a hair shy under the top of the cylinder when tdc - which now makes sense to me the need for the slant head. I was wondering if I should shave down a bit of the top of the cylinder to tighten the squish closer to the head

It's hard to tell for sure but it looks like your piston angles upward for a little bit then is flat on top. If this is the case and you decide to do a complete top end the new top end's piston will be domes and will have increased compression over your current setup.

 

[Neo_Epoch]

It's hard to tell for sure but it looks like your piston angles upward for a little bit then is flat on top. If this is the case and you decide to do a complete top end the new top end's piston will be domes and will have increased compression over your current setup.

Piston looked kinda flat to me, but I didn't get a real good look at it. I went ahead and ordered the top end you had suggested. I have a feeling the jb weld isn't going to go well and just to have the newer cyl on hand any way is a better idea.

After thinking about it within a partially photographic memory, the slant head does hang slightly in. With all that being said, hopefully the new piston is a coned head. Would be a nice little upgrade

 

[gary55]

Piston looked kinda flat to me, but I didn't get a real good look at it. I went ahead and ordered the top end you had suggested. I have a feeling the jb weld isn't going to go well and just to have the newer cyl on hand any way is a better idea.

After thinking about it within a partially photographic memory, the slant head does hang slightly in. With all that being said, hopefully the new piston is a coned head. Would be a nice little upgrade

The piston might wind up a little lower in the cylinder at TDC. The dome will make up for that as far as compression compared to the flat piston you have. Then it's just a matter of doing the solder test to dial it in. I would just put the new top on, check that the piston isn't coming above the top of the cylinder at the edge just for good measure, then put it together and run it to see how it feels. A little extra oil for those new rings wouldn't hurt for the break in.

 

[Kpi890]

JB well makes a product called Steel Stik and it’s a putty you can use to try and repair that. I’ve used it many times at our farm for reapairs. It’s drillable and paintable once cured. It’s great stuff and worth a shot on there!

 

[gary55]

Steel stik is only good to 300 degrees.

 

[Kpi890]

Steel stik is only good to 300 degrees.

Ahhhh damn!