They all do that, sir !!!
I have a VH500 swingarm.
It shed a gudgeon pin circlip, twice, and ruined the bore. The first time I assumed the noise was an "ariel one" and kept ongoing until the oil cloud behind required me to find out the cause. Rebore required.
After buying a later alloy engine and using its iron barrel to convert my VB600, I put the alloy head onto this VH500.
Just the barrel and a JP piston. Nothing else. I then decided to put a sidecar on it - which took months.
When I finally got it out on the road, it was immediately making a pretty strange noise under load. it wasn't one of the usual ariel noises.
I decided not to follow Len Ore's advice on the subject of noises and leave it alone as "it will get better, get worse or stay the same" and stripped the engine to the crank. I thought it had shed it's gudgeon pin circlip again (similar noise) but no; piston, barrel and pins ok.
As I had the alloy, five stud, barrel on an four stud earlier case I took the opportunity to change the cases (to the right 5 stud ones) and change the bearings.
The big end seemed ok, so I left it alone (I couldn't get my other crank sorted in time - see other posts here)
I spaced the crank, with the right play, and put it all together.
Had a few teething issues.
Noise is still with me, after al this, and probably getting worse.... best described as a clanky whine.
- Doesn't improve when warmed up.
- It occurs under load and can just be heard (by me) when revv'd at idle.
- If you ride with a light throttle, then it can almost be eliminated
- It can also be reduced by moving to half retard (which causes performance loss and some banging in the exhaust). I have retimed the bike a few times now and also run it over advanced and over -retarded to see.
- It's not there all the time either, but any quick turn of throttle will usually make it happen (you can ride along and turn the noise on and off by doing this)
It must be an engine noise, as the load and retard have an effect. Right ?
Tell me it's not the JP piston eh ? That was the only thing I really changed ............
I have a hepolite piston now, but I believe the JP runs with more clearance but putting it in will give me a larger ring gap and possible slap.