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General Category => Yamaha FJ1100 / FJ1200 Running Problems => Topic started by: Lotsokids on July 14, 2013, 11:24:28 PM

Title: Engine Miss - Under 2,000 RPM
Post by: Lotsokids on July 14, 2013, 11:24:28 PM
My bike has developed a "chugging" or miss under 2,000 RPM with a slow roll-on with the throttle. I took it out yesterday and refueled, but it was VERY hard to start, and almost didn't. I reached 145 MPH (I don't do that very often) and it pulled really strong.

Any thoughts? :unknown:
Title: Re: Engine Miss - Under 2,000 RPM
Post by: Flying Scotsman on July 14, 2013, 11:32:49 PM
I think I would look at the carbs...
High speed circuit is ok
Mid range ok
Low speed circuit or choke not so good.
Pilots or idle air fuel mixture.
Title: Re: Engine Miss - Under 2,000 RPM
Post by: RichBaker on July 15, 2013, 11:42:39 PM
If it started this AFTER the refuel, I'd be looking at the new gas..... Water in it, maybe?
Title: Re: Engine Miss - Under 2,000 RPM
Post by: Lotsokids on July 16, 2013, 11:19:08 PM
Quote from: RichBaker on July 15, 2013, 11:42:39 PM
If it started this AFTER the refuel, I'd be looking at the new gas..... Water in it, maybe?

I thought of that also. I'm running some complete fuel system cleaner through it now.
Title: Re: Engine Miss - Under 2,000 RPM
Post by: mr blackstock on July 18, 2013, 02:02:17 AM
G'day,

mine was missing badly at low revs, I suspected electrical, so just for a try I put on some spare spark plug caps off another bike and the problem seemed much better.  So I bought 4 new NGK and the problem has all but disappeared.  I will get some new plugs soon and that might solve the issue completely.

Anything to avoid pulling the carbs apart!

Cheers, Gareth