Strange Airhead engine problem solved !

[supershaft]

I am afraid to say that all that trouble is pretty much a classic case of not using a mechanic's stethoscope. Yes, they look funny and you should really put on a white lab coat and maybe fill up your pipe and smoke it just for full effect but they work. I have a couple of times in my life walked up to two or three mechanics arguing about where a sound was coming from and I positively identified the source in a minute with a stethoscope. The trick to them at least at first is to use them without the contact rod. Just that little cup at the end will usually direct you right to the source of the noise or close enough to put the contact rod back on for a closer listen.

I haven't seen this problem yet. Is there a rash of swapping back to the old clutch in our future?? That would be yet another step back to why it got changed in the first place IMO.

The early style flywheel is one piece.

I wonder if anyone has tried combining the later clutch to the earlier flywheel?

[chasbmw]

Jim Cray in the UK has fitted a lightened early flywheel to the light flywheel bikes, the owner of the bike was very happy with the result!

Motobins have heavy flywheels on sale for £40, which is cheap indeed, however postage overseas might be a little expensive.

I am coming to the reluctant conclusion that the starter problems on my R90 are due to wear on the starter gear, as the flywheel is lightened, then I'm not looking forward to replacing it.

[supershaft]

I was wondering if anyone has put a late model pressure plate one an early model flywheel? That would be the best of both worlds for some that prefer more flywheel. I might even want some flywheel if I rode these things in the dirt much. The problem with what Jim Cray did is that then the bike is stuck with an early clutch and they are junk compared to the later ones. They are WAY more likely to slip!

[bereahorn]

[chasbmw]

SS

Jim certainly would have had the fabrication skills to do the job, I think we discussed something similar when he built up my R90 as I think the job included a end plate to the gearbox and it would have involved me in too much money.

[supershaft]

Jim and a lot of other people could do it if it is reasonably doable. I have never even thought of it until just now. I suspect if it was reasonably doable Siebenrock or somebody like that would already be offering it? I am going to look into it. I have done a bit a machine work for hire but I have never owned my own equipment. Nevertheless, I have a good friend that is set up to do stuff in high volume. He owns Alleven RC and he owns all of his own CNC stuff!

[Voorspoed]

Goodday people!

Tell me, did your bike sound like this before you fixed it?

http://www.youtube.com/watch?v=phviz4wQInk

http://www.youtube.com/watch?v=YTxj9DKpNLY

Mine sounds like it has the same problem.

Looking fwd to your reply!

Willie Landman
willie@swanniebraai.com

[Kai Ju]

SS, the early flywheel is actually a two piece assembly with the ring gear being shrunk onto the flywheel.
No welding that I can tell.

[disston]

^^^^^^^^^^^^^^^^^^^^^^^^^^^

Agreed

[supershaft]

I knew that. I just forgot. I think robtg said he has replaced them before.

I looked into putting a late pressure plate onto a earlier flywheel. As I suspected, there is no easuy way to do it. I figured as much or else someone would already be offering that mod.

[DoktorT]

Originally Posted by supershaft

I am afraid to say that all that trouble is pretty much a classic case of not using a mechanic's stethoscope.

Must agree that the mechanic's stethoscope is an essential diagnostic tool that works very well to find most any type of noise. I used one virtually every day for 15 years to quickly find noisy bearings and pumps and rockers and ................ 1 minute accurate diagnostics time and again. Top drawer tool box essential. Nothing like expensive either.

[shel-bou]

hi Willie I think you might want to look at the front cam bearing. No personal experience but I hear the aluminum cam bearings were problimatic. SS may enlighten.

[supershaft]

I have heard that but have seen no evidence of it. Just about all motorcycle cams run in aluminum bearings. Mine is fine after 101,000 miles. Right at 70k of it with a sport cam that gets reved regularly to 8krpm. I have heard that sport cams will destroy the aluminum bearings. Not mine or others I have seen in use.

[GearHeadGrrrl]

Had the ring gear come loose at around 50K miles on my '84 R65LS. Put on a new clutch carrier and after another 50K miles, no problems.

[squish]

Originally Posted by DoktorT

Must agree that the mechanic's stethoscope is an essential diagnostic tool that works very well to find most any type of noise. I used one virtually every day for 15 years to quickly find noisy bearings and pumps and rockers and ................ 1 minute accurate diagnostics time and again. Top drawer tool box essential. Nothing like expensive either.

Or save yourself some cash and just use your long handled screwdrivers,
Work nearly as well and you don't need the lab coat or the pipe.

Flat headed works slightly better since there's every so slightly more contact area.