Big Bore Kit

Bugger!

I treated the big bore 1370 head gasket with Hylomar spray gasket seal on both sides and then put a bead of ThreeBond 1211 selant around all of the water jackets on both sides and a small bead around the oil passageways for good measure.

Each coat of gasket seal is ready in 10 minutes and the 1211 skins over in 30 minutes.

While installing the head I managed to drop a small screw driver down the cam chain tunnel

Still head is on and properly torqued down now. There's no sign of the screwdriver. I've tried fishing around with a long screwdriver with a magnet on. Will have to take the sump off again and hope I can get it from the bottom

I cannot see why (like most) anyone would be concerned by the width of those liners ??????

No problem there at all ?????????

I have seen many water cooled liners like that run without any issue at all & no problems.

Ignore any alternative advice in my own experienced opinion.

Pete F

The article was written by Gert Roewer from Australia. He is obviously a talented machinist! Here is the link to the article:

www.dreadsbikersite.com/Z1300/1502_bigbore.htm

The article on the 1502 built using 750 pistons was written by Gert Roewer from Australia. He is obviously a talented machinist! Here is the link to the article:

www.dreadsbikersite.com/Z1300/1502_bigbore.htm

Has anyone ever gotten any dyno data on a bike that has had that done to it? I'm curious as to the difference it makes. Thanks!

Hi guys,

I hooked up the battery today to run some compression tests after the 1370 re-bore. Was surprised by the results:

1 10 bar
2 9 bar
4 8.5 bar
4 8.4 bar
5 7.6 bar
6 10 bar

No carbs on, no exhausts on, all spark plugs removed.

Can it be normal to have this much difference between cylinders after a re-bore? Do I need to check again after It's been run in?

I had the head vacuum checked for cracks and pressure checked for valve seat leaks.

I would have thought all of that with new bores and new rings would have given me a much more even set of results.

Should I try with a little oil in each barrel?