Topic: 350 twin cam question

[oldhondafan]

I have a SOHC4!  But this Q concerns my 73 cb350 twin.  It sat for 10 years, but was running when I bought it.  It was professionally tuned in July 06, everything less the cam chain tension which was felt to be ok by the mechanic.  I've ridden it just 600 miles since then, and at the end of that just before winter I noticed a cam chain noise.  I assume this arose due to loosening just as part of the exercise I've given it after sitting for so long?  I don't sense that a big failure is imminent.   I just adjusted the cam chain now as part of bringing it back on the road for the new season.  The cam noise is gone.  But now I get valve noise (clatter) under load (accelerating).

My query then is.....can a cam chain tension adjustment affect the valves this noticeably?   I do notice in the manuals that cam chain adjustment always seems to be first thing covered in the tune up sections.

Thanks.

[kettlesd]

You are sure its valve noise? Im not sure why the noise would be there under load only, if it is the valves....

Check your valve clearances. If it is indeed excess valve lash, Im sure the valve clatter was likely there already, and was just masked by the previously noisy camchain - which is now out of the picture.

[wardmoto]

While the 350 twin's(I own 1) cam chain adjuster is almost as bad as the 350F's(I own 2) it shouldn't give you fits.  I was raised on my 350 twin, and abused it shortly after I turned 16.  I felt sorry for it(18 years later) and took it under my wing while I was awaiting parts for my 350F cafe/Rc172/CR350 (ok I made the last one up...there were no privateer Honda kitted small bore "CR" bikes) build.  I took the opportunity to do some exploratory inspections to the motor while I had it out and I remember back in the day, while I  was butchering the butter soft screws that held it together...I remembered how damn noisy the valves were if they were not to spec or slightly tighter(not recommended)  Sounded like 412 bb's dropped in the head!  Double check the clearances and if in warm weather consider 20w50 oil and change it often...never trusted the centrifugal oil filter.