The International CBX Owners Association

Since a winter lay off my 79 cbx is not running smooth.After new plugs i traced the fault to carb no5 as the new spark plug was clean compared to all the others ,with the plug out and still attached to the plug lead it is firing ok as there is a healthy spark so the fuel must not be getting through is there anything i am missing and is there a simple way to unblock the carb without dropping the engine.

Some people swear by, and have supposedly been successful with Yamaha Carb Cleaner or Seafoam mixed to the fuel and running a tank full, or so, through the engine. I have not been that lucky myself and am currently working on the carbs off the engine on both the 79 and the 80.

Yes KT, welcome for sure. ISTR that Mike Nixon had detailed an 'on bike' cleaning method...

Yes. Here: http://www.motorcycleproject.com/motorc ... short.html

If that doesn't do it you're gonna obviously have to tilt the moor and get them off, but as a noob that did it for the first time last year, it sounds a lot worse than it is.

Check out Mike's site and let us know how it goes. If you ask you'll get help here, and these guys know this stuff inside out and backwards, particularly Dave and Mike who both clean and rebuild these for fun and profit. You'll find that both are more than generous with their knowledge and experience.

N.

EMS wrote:Some people swear by, and have supposedly been successful with Yamaha Carb Cleaner or Seafoam mixed to the fuel and running a tank full, or so, through the engine. I have not been that lucky myself and am currently working on the carbs off the engine on both the 79 and the 80.

DON'T EVER use Yamaha carb cleaner in the tank, it will melt the plastic fuel strainer in the tank, follow the directions and always pour the mixture of gas and Yamaha carb cleaner directly into the carbs through the carb inlet.

Why not?

This product is designed to be run through the fuel systems of either 2 or 4 stroke engines and some of them must have plastic bits in their fuel systems. The instructions don't say pour it into the inlets, it only says pour X amount per gallon of fuel into the fuel tank and run the engine.

Confused in San Antonio.

RC166LVR wrote:Why not?

This product is designed to be run through the fuel systems of either 2 or 4 stroke engines and some of them must have plastic bits in their fuel systems. The instructions don't say pour it into the inlets, it only says pour X amount per gallon of fuel into the fuel tank and run the engine.

Confused in San Antonio.

I'm not sure what your confused about, If you are holding a bottle of Yamaha carb cleaner, part# ACC-CARBC-LE, it says right on the lable in the directions, the last sentence in step #3 in BOLD PRINT, "DO NOT PUT IN FUEL TANK".

Yamaha carb cleaner is not ment to be consumed and combusted in either a 2 or 4 stroke motor.

Sorry.
My bad.
I thought you were referring to the Yamalube Ring Free Fuel Additive.

Which BTW, quickly cleaned up a low circuit lack of fuel into the #1 carb and now the old girl runs better than she has in the past few years.

Glad you got it going with the Yamalube additive, much easier than pulling the carbs.

Amen, brother.

Anyone with any seat of the pants experience with the Yamalube Ring Free additive vs Sea Foam vs Techron for that annoying carb gumming (even if you keep Stabil in the thing always)?

I've come to the same conclusion as the CBX gurus and others on this forum - the CBX responds (like lots of things) well to regular exercise.

CBX motors love to run, run her hard, feed her well with top quality fuel & oil & you'll think she's running for the roses... Leave her idle (without preparation) for a long time & she will spank you like a whip cracking porn star ...

Couldn't agree more, but I relied on Stabil and a battery tender and only rode her every 3-4 months, much to my chagrin.

I now know that I'd rather pile on the miles and enjoy the old girl running as she should, than deal with results of my own neglect.
She ran so well this weekend (150 miles in the Texas Hill Country), I fell in love all over again. Very few bikes out there with the feel and character of the CBX.

Long live Iramajiri-san's creation !!!