xj900f 58l engine differet than 31a.?

Hi, is 58l engine any differet than 31a in Any way.?

 

Bigger bores
Bigger pistons
Bigger carbs
Different TCI
Different head
Different clutch boss and hub

Umm yeah apart from that I think it's pretty much the same.

 

Okay,,, thanks,,,,, so 31a has longer stroke,,,?

 

Both are 68 mm stroke

 

I'd like to know the reason for the question.
I purchased some 2nd hand 58l pistons from Germany and new 58l std rings and had a 31a set of jugs bored out to suit for my 31a 900 engine.

It worked. Walls are a bit thin mind you and in all honesty the pistons and jugs are back on the shelf after I switched back to the normal 31a pistons and normal 31a jugs, not for any reason apart from I couldn't work out why the bike would die... Ended up being the regulator, strangely.

 

I have to assume @Jim-Dk thought they we’re both 900’s when in fact 31a is an 853 and 58l is 891

 

Using 31a block with 58l pistons will raise the compression as the blocks are different heights to help compensate
I don’t think that was the problem though as you did diagnose an electrical issue

 

The problem I have now is the bike is finally working great... I'd love to stick the 58l pistons and bored jugs back in but I would need to acknowledge my insanity then.

 

Living with an 853 I think is good