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General Category => Yamaha FJ1100 / FJ1200 Running Problems => Topic started by: Bluezero on January 09, 2015, 02:33:57 PM

Title: Misc. Things
Post by: Bluezero on January 09, 2015, 02:33:57 PM
Hey y'all, got an 89 Fj1200 with about 80k miles on it and the other day I noticed that I could smell gas in the oil. I think I've narrowed it down to the choke not functioning properly as cylinder four will not fire when it is on. The only thing I can guess is that maybe the gas is washing down the cylinder walls when the choke is left on too long. I remedied it by not using the choke for too long and using a bit of throttle to keep it on till it's warm. This has kept anymore gas from getting into the crankcase but does anybody have any ideas what could be causing this to happen when the choke is on?

Also, the cam chain is fairly loud which I hear is normal but I called a shop and asked if they could swap out the tensioner and the guy informed me that the whole top end of the engine probably needed to be refreshed with new gaskets, rings, chains, and valves which he told me he could do for around 800-1000$. I've heard these bikes are fairly bulletproof so is this something I should be considering at such "low" miles? The mechanic also told me he hasn't worked on one for 20 years so he may not be familiar with their longevity. Sorry for the wall of text and thanks!
Title: Re: Misc. Things
Post by: Mark Olson on January 09, 2015, 03:42:35 PM
Remove and clean your carbs , check jets and float heights , emulsion tubes etc. Be sure to examine the choke linkage for wear and proper travel.

Gas in the oil is very bad for your engine. Set idle to 1100rpm and see if the rattle went away.
Title: Re: Misc. Things
Post by: Bluezero on January 09, 2015, 03:49:02 PM
I will get on checking those things. As for the idle it's currently set to 1100 rpm and I can hear it throughout the rpm range and speeds up with higher rpms.
Title: Re: Misc. Things
Post by: roverfj1200 on January 09, 2015, 04:14:58 PM
Quote from: Bluezero on January 09, 2015, 03:49:02 PM
I will get on checking those things. As for the idle it's currently set to 1100 rpm and I can hear it throughout the rpm range and speeds up with higher rpms.

Would most likely be the starter chain or alternator chain. I think you can get a rattle from the starter clutch to (someone will chime in)


FJ carbs are known to leak from time to time and I have found if left on the side stand overnight fuel can run into the lower cylinder. Good carb clean and adjust will minimise this.
Title: Re: Misc. Things
Post by: Bluezero on January 09, 2015, 04:18:35 PM
Quote from: roverfj1200 on January 09, 2015, 04:14:58 PM
Quote from: Bluezero on January 09, 2015, 03:49:02 PM
I will get on checking those things. As for the idle it's currently set to 1100 rpm and I can hear it throughout the rpm range and speeds up with higher rpms.

Would most likely be the starter chain or alternator chain. I think you can get a rattle from the starter clutch to (someone will chime in)


FJ carbs are known to leak from time to time and I have found if left on the side stand overnight fuel can run into the lower cylinder. Good carb clean and adjust will minimise this.

Okey doke thanks, I hear the sound coming from the front of the engine which is why I assumed it was a cam chain but it could be echoing maybe?
Title: Re: Misc. Things
Post by: Mark Olson on January 09, 2015, 04:32:55 PM
Use a stethoscope or some other listening device to pin point the area in question .

Did you check/adjust your valves?
Are the header nuts tight? good gaskets.
Title: Re: Misc. Things
Post by: Pat Conlon on January 09, 2015, 04:58:40 PM
On the '89, with your fuel pump off, there is a one way valve which should prevent fuel from flowing from your tank to the carb bowls (by gravity)
At the fuel pump, disconnect the fuel line output (line to the carbs) if you see gas dribbling out the fuel pump, there's your problem.

Also, as mentioned, time to clean your carbs and replace the float needle seat o rings....check your float heights.
Title: Re: Misc. Things
Post by: charleygofast on January 09, 2015, 06:10:28 PM
All of Mark and Pats good advice :good2: and change that crappy gas infested oil if you haven't allready.
Title: Re: Misc. Things
Post by: Brook on January 09, 2015, 08:05:14 PM
..... bluezero,

was Cahill's the shop that you talk to??

If you can not solve the problem, Give Reed a call at Factory Four in Plant City  764-8373.
Reed is a very good motorcycle mechanic.

and If you made any Saturday nights runs, [about five years ago] starting at the...LOT.. in Clearwater. You may know him.

And just happens, he has a 88-89 FJ for sell.
Title: Re: Misc. Things
Post by: roverfj1200 on January 09, 2015, 08:25:39 PM
Quote from: Bluezero on January 09, 2015, 04:18:35 PM
Quote from: roverfj1200 on January 09, 2015, 04:14:58 PM
Quote from: Bluezero on January 09, 2015, 03:49:02 PM
I will get on checking those things. As for the idle it's currently set to 1100 rpm and I can hear it throughout the rpm range and speeds up with higher rpms.

Would most likely be the starter chain or alternator chain. I think you can get a rattle from the starter clutch to (someone will chime in)


FJ carbs are known to leak from time to time and I have found if left on the side stand overnight fuel can run into the lower cylinder. Good carb clean and adjust will minimise this.

Okey doke thanks, I hear the sound coming from the front of the engine which is why I assumed it was a cam chain but it could be echoing maybe?

From the front........ That will be a loose header and or header gasket.. Something to check.
Title: Re: Misc. Things
Post by: Bluezero on January 10, 2015, 02:37:08 PM
Awesome thanks for all the suggestions guys. I'll start checking everything and come back when I figure out exactly what it is.
Title: Re: Misc. Things
Post by: krusty on January 10, 2015, 07:20:06 PM
Surprised I didn't see carb syn mentioned or did I miss it? Unsynchronised carbs can result in a "rattle".
Title: Re: Misc. Things
Post by: Bluezero on January 14, 2015, 04:52:59 PM
Well today I was able to change the oil and filter along with the plugs but didn't have enough time to learn how to check the valves. Anyways, I took a video so y'all can hear the noise. Thanks for the input. http://youtu.be/QV1gUpp9xjM (http://youtu.be/QV1gUpp9xjM)
Title: Re: Misc. Things
Post by: Nimbus on January 14, 2015, 05:30:08 PM
Well it kind of sounds like mine did last spring. Found #4 compression down to 50, ending up needing the valves lapped. :unknown:
JMHO
Title: Re: Misc. Things
Post by: Bluezero on January 14, 2015, 06:09:44 PM
Damn -_- well I guess I'm doing a compression test this weekend thanks for the input.