Still Not Working Right!

[DEmily]

So your not running the cone type individual filters? I had a very similar problem and come to find out, after dealing with the K&L pilots, the indy filters I had was blocking off air ports in the front of the carbs. Took the filters off, put the original airbox back on with a new filter and it runs like a champ in all rpm ranges. No more black plugs.

[Jacobite]

No the airbox is stock, and the filter just a standard aftermarket replacement filter (Cleanair ? - something like that)

[JohnSg]

Jacobite,

Now I gotta ask, just what the heck does your signature say/mean?

[Jacobite]

My signature is in gaelic and is the rallying cry for my Clan (Cameron). The rallying cry was used to call the men of the Clan together before marching off to fight another Clan or the English.

Translated literally it means "Sons of the hounds, come here and get meat"

A friend (and clansman) of mine opinioned that the modern translation should be "Come on you sons of bitches, we're going to have a big feed!"

[JohnSg]

LOL! That's pretty cool, thanks.

[srq68]

One good advice I would give it to fork out the $13 to your Yamaha dealer for their carb cleaner product. The stuff work really well, better than any spray cleaners from the local stores.
I cleaned a 1930 Rolls Royce carb that hadn't run in 38 years with it, soaked overnight, amazing! The varnish just melts off of parts as you watch.
Just my $0.02

[pgg]

Scotsman, if the plugs are black from cruising speeds, and the jets are oem, I'd immediately drop the needles down or lean off the floats, or do a combination of both.

[Jacobite]

Thanks for the additional suggestions. I haven't had a chance to pull the carbs off this weekend. Did sons KX250 fork seals and put forks back on, replaced a wheel bearing on our Honda ATV, and set up a backyard pool - there are not enough hours in the day.

I will pick up that Carb cleaner you mentioned. I had already reset the floats, with no improvement - and now the needles & seats & floats are all new - OEM, at factory settings - with no change, so I am betting I have a plugged jet or two. I am actually hoping so, because I am getting tired of taking off and putting on the carbs (this will be time #4, not including what the Yamaha shop did). If the temperature would drop a bit here - my shop feels like an oven.

I'll post when I have tried all your suggestions and let you know how I made out.

[Jacobite]

Well I finally got back to the bike (last night - started at 9:00, finished up about 11:30). I cleaned the carbs (again), paying particular attention to the pilot jets, air jets, and idle mixture screw. I didn't notice anything amiss or clogged - but a brief test ride seemed to indicate a significant improvement - so maybe there was something lodged in that circuit. I'll take it for an extended test run tonight after work & will let you know how I make out. I am interested in seeing if there is any improvement in mileage.

Thank you all again for your assistance!

I didn't get to the Yamaha shop yesterday - but I picked up a can at the Honda dealership & it seemed to work very well (stronger than my usual wal-mart product).

Thanks again.

[sidecarKev]

Are you seeing improved take off? Better revs in the 3-4000 ranges? If you are you probably had something clogged. Great news.

[Jacobite]

After the bike warmed up for 5 minutes or so, much better revs in the 3000-4000 range. Better take off as well. I only went for a very brief drive, so I'll get a better feel for it tonight.