New Airhead problem?

[dpmonk]

I recently purchased a 74 R90/6 showing 32k on odometer.
P.O. supplied many records of shop work he had done on bike (spent lots of bucks)
and last record of valve adjustment was at 28K but I was told it had just had complete fluid change and adjustment.

When I first attempted timing I found it at full advance at idle. So far I have changed points, (found points plate is bent and ordered new one) and managed to get it timed with the plate turned counterclockwise as far as possible and setting points gap at .015.

Timing helped but still wouldn't idle smooth and seemed underpowered.

Here is where I admit stupidity. After about 500 miles I finally checked valve clearance and found that at TDC there was no clearance on either side.
Torqued heads and set clearance and it is like a new motorcycle. Idles smooth
and runs like a spotted ape.

My concern is how much damage was done by running the bike with no valve clearance. My next step is to check compression and monitor for recession at 500mi and 1k intervals.

Any more suggestions are welcome!

 

[Polarbear]

Well, maybe none

If it ran like a spotted ape, you're probably fine. Its amazing how much abuse the older Airheads can take. I have one in my R100/7 at 330000 miles now and the original valves. I highly recommend you use a lead additive, if the original valves are in yours. I do! The fake lead additives are good and a pint bottle gets me near 40 tanks of treatment and I have the Heinrich 9 gallon tank. It stopped my valve recession to maybe a once a year adjust. If you want real performance, throw the points out and do a DYNA3 ignition. A whole lot better. PS; I bought the R100/7 above, new in '78 and it could never be sold. A real keeper. Randy13233

 

[dennisdarrow]

Would you believe Nixon?

The same applies to the stuff that PO's pawn off as the truth. Examples run rampant on here.
For me: The PO of the 75 R90 I currently ride advised me that all was maintained recently from wheel bearings, splines, filters, carbs rebuilt, and fluids. Such a joke.

Mud dobber nests covering the air filter up into the starter motor chamber

Oil filter completely clogged with particles and crud

Parts missing from clutch throwout assembly

Trans splines dry as a bone and cruddy

Carb diaghrams and O rings dry and brittle crumbling when touched

ON AND ON AND ON

Many of these guys, I call them EBay kings, find junk and some good stuff, swap parts from one bike to the other and pass the bike off as much more than what it really is.

My bike obviously had the bag mounts removed, the exhaust shields removed, and the crash bars removed. The scars are obvious yet the PO advised that he knew the bike was stock or some other PO must have done that, while telling how he found the seat and other parts on Ebay...................

Anyway, to end this rant, be prepared, when buying one of these old things to replace all maintenance items, do a thorough maintenance from wheel to wheel including the splines, and then RIDE THAT PUPPY............

Mine turned out to be a real keeper.....................Dennis

 

[dpmonk]

Previous Owner

The previous owner is a MOA member and I didn't buy on Ebay for the reasons you said. He provided detailed receipts for the work he had done including carb rebuild, new clutch, replaced input shaft, rebuilt alternator rotor... the list is pretty extensive and expensive and from all indications accurate.

The only thing I didn't find was who did the last valve adjustment.

I blame myself for not checking valve clearances first. I should have known it was too quiet for an airhead!

 

[dennisdarrow]

lololol.......I need to be quiet because my PO often times reads these things. Good Luck..........Dennis

 

[tuber1]

On the older /6 models the valves will/can tighten up by themselves. Then again, some owners purposely tightened their valve lash to quiet the bike. Those old bikes should rattle, just not alot. And when you shift, the trans will clunk...hope you enjoy many miles with it.