Installing my 124 kit this weekend and FM is closed so I can’t call them.

Pregapped rings in the kit but no documentation other than the canned instruction sheet that comes with the rings.

The sheet indicates minimum per inch of bore ring gap of .045” for the top ring, and .005” second ring. 4.25” bore gives .019 gap on top and .021” second ring. I know these are minimums.

Harley spec is 10-16 top and 16-24 second on stock bore.

I measured a perfect .019 for the top, but get .029 on the second ring. Measured both 1” and 2” down.

Should this stop me from installing until I can call them?

 

Try the 2nd ring in the other cylinder?

 

I tried that. Same result. Both second rings measure the same.

 

I'll be doing this in the next few days. That gap does seem wide. I'd call them and ask.

 

They sent me a 4.50" bore .014 base gasket for mine, what base gasket did you get?

 

Did you make a typo on when you said .045" end gap on the top ring .005" on the second?! This CAN'T be right, these are WAY over and under the correct end gap. Rule of thumb is .003" to .004" end gap per every 1" diameter bore,this would put you at a minimum of .013" to a max of .017" (unless you're building strictly for racing) . These were the typical parameters I used back years ago while engine building was still my profession, maybe these animals are a bit different but I still advise you seek out these specs from a trustworthy source before you go any further. Man,---.045" you could measure that with a carpenter's tape measure! In this game a half of one thousand'th (.0005) can make or break your engine. I think you should definitely not rush into this one.

 

Good advice right there.
Bob

 

Using the included Wiseco chart it shows for High Performance Street Strip should be.0045 X Bore which comes out to .019125" for the top ring. The 2nd ring at .005 equals to 0.02125" gap. These are the pistons and spec sheet that FM uses in their 124 big bore kit.

 

That is the chart i was looking at. My top measures .019 but the second ring is coming in at .029”, not .021” . Decided to hold off putting it together until I talk to FM.

 

I have one that is .0265" on the 2nd ring so I'll be contacting them too.