engine races

[4shorts]

Go get a 2007 new YAMAHA. ...............lm

Wow. Do I detect a touch of sarcasm in that? At least you could have said "Get a new Honda"? Not the kind of advise I would want!

[jesmed]

I guess I'm a failure as a Honda mechanic. Maybe Yamahas are simpler. ;-)

[Michael Stoic]

Just to rule cabling out completely, I'd try unrouting the throttle cable as much as possible. IIRC it can be placed temporarily in such a way as to allow the most gentle curve from throttle grip to carbs. I recall doing that at one point and discovering that it was the cable after all. In the "loose" position the cable would not interfere; in the properly routed it would. There was a very slight degree of pressure from the sheathing bend which caused the problem. Keep in mind, multi-strand cables running in multicoil sheathing (inner surface) +40 yrs can be a factor here.

If you've tried the more sophisticated solutions and they did not fix the problem, it might be time to revisit the simplest ones.

MS

[jesmed]

Michael,

I'll sure give it a try on my next visit to the garage...by the way, are new throttle cables available? I don't think I've ever seen one on eBay...

Jesse

[piecutter]

Have we tried actually looking down the throat at the slides while it is "racing" to actually see if the slides are closing?

[jesmed]

Yes, and just so I have a belt AND suspenders, two years ago I replaced the stock slide springs with stiffer ones of almost identical dimensions from the local Ace Hardware. Because I'm grasping at straws at this point, I have wondered if the stiffer springs might be causing mischief in some way I didn't anticipate, but I haven't come up with a plausible scenario in which stiffer springs could be causing an air leak. For sure, I know they're bottoming the slides out consistently.

[piecutter]

Ok, now how about removing one spark plug and running it on one cylinder, and then the other to see if you can narrow it down to one side or the other.