Connecting Rod/Flywheel clearances

[tinkerman]

Working on my 88 evo top end - just cleaning up the cases and trying to determine if the bottom end is solid.

Just measured my rod flywheel clearances and it seems like they are within spec at the crank. I have about .025 and the manual specs .03.

My question is that the front rod, although it has minimal side play and end play at the crank can be tipped at the top end a fair bit. Not sure I am describing this well but the top end of the front rod can be tipped back and forth across the engine about 1/8 of an inch almost like it was supported by a slightly rounded bearing design. This movement is about twice what I see in the forked rear rod. And the movement at the top of the rear rod is about what I would expect for the allowable end play at the crank.

If I have made a balls of explaining this let me know but what I need to know is if the front rod should be able to tip a little back and forth across the engine. There is no disernable free play up and down on the rod and minimal side play but this tipping play has me puzzled. I have seen bearing designs that would allow this but looking at the con rod bearing in the manual doesn't seem to explain it.

Tink

[choseneasy]

 No up/down movement is good. The front will have more of the "rock" than the rear because of the rod surface. If your measurement is 0.075 you are getting close to limits.   0.100 is no good. It is hard to get a decent measurement but use a dial indicator at the top of the connecting rod and use care not to measure the end play with the "rock" of the rod.

[TheSwede]

One thing is telling,,If the bottomend is quiet and there is
no clicking or clacking sound,,especially on decreasing RPM
I am sure the bottom end is totally OK,,remember Harley
bottom end is very sturdy and made for lugging,, the only
thing that kill rodbearings is high RPM:

Best Regards
TheSwede

[choseneasy]

I am not too crazy about lugging for the bottom end, especially cracking the throttle when the revs are under 2000rpm. That will destroy bottom ends in no time.

[tinkerman]

OK This sounds good to me. I figured it was unique to the single crankpin split rod design. All the con rod bearings in the british stuff I have worked on are plain bearings. I will check the play at the top with the dial indicator but I am thinking it is good to go.

Just got to finalize my parts list for the top end and I will have that stuff home for when I get back home in Feb.

Appreciate the input folks; your experience moves me ahead by a factor of ten.

Have a good New Year. You will be hearing from me.

Tink

[tinkerman]

Checked the play at the top end of the front rod.

.060 side tipping play (if there is such a phrase) so she is good to go. Throwing the cover over it for now and will get the parts moving so that they are home when I get back from my first tour in Feb.

Thanks for the input.

Tink