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General Category => Yamaha FJ1100 / FJ1200 Running Problems => Topic started by: ArmArak on July 06, 2019, 11:35:03 PM



Title: Idle issues + poor responsiveness
Post by: ArmArak on July 06, 2019, 11:35:03 PM
Hi Guys,
I have been having problems with my stock 1986 fj1200. It starts; however, idles low at around 1000 rpm. When the choke is pulled revving takes it up to around 3000 and stays there, pushing the choke in brings it back to 1000. Here when throttle is applied fast the bike doesn't climb in rpm, sputters and stalls. This doesn't happen if the throttle is applied very gradually. https://www.youtube.com/watch?v=5u8BnNQO25I&feature=youtu.be (https://www.youtube.com/watch?v=5u8BnNQO25I&feature=youtu.be) link to a video showing problem.
Thanks


Title: Re: Idle issues + poor responsiveness
Post by: Pat Conlon on July 06, 2019, 11:47:29 PM
Clean your carbs, in like, don’t just spray some cleaner down the throat or pour some cleaner in your fuel tank, no, no, take the carbs off the bike and take them apart and clean them correctly. The idle circuit, the pilot jets and the jet nozzles could be clogged, the choke fuel pick up clogged, and the carb slides could be gummed up.
http://www.fjowners.com/index.php?topic=655.0 (http://www.fjowners.com/index.php?topic=655.0)

Don’t leave fuel containing ethanol in your carbs.

Spend $24 and buy this kit from RPM: http://rpmracingca.com/proddetail.asp?prod=carbkit (http://rpmracingca.com/proddetail.asp?prod=carbkit)
It’s a great value. You need fresh O rings anyway, the new ss allen head screws (replacing the butter soft oem JIS screws)  are the frosting on the cake.

If you can’t or don’t want to do the carb cleaning job yourself and you have no one local you trust, take your carbs off, drain the gas out, let them throughly dry for a day or two, box them up and send them to Robert @RPM.
He will get the job done right.

BTW there is nothing wrong with a 1,000 rpm idle speed.

Cheers
Pat


Title: Re: Idle issues + poor responsiveness
Post by: aviationfred on July 07, 2019, 05:31:58 AM
As Pat says...1000 RPM at idle once fully warmed up is fine. The photo is from my Haynes manual.

I had a similar issue with carbs that sat for a few months. The culprit ended up being the fuel inlet screens flunked up


Fred


Title: Re: Idle issues + poor responsiveness
Post by: ArmArak on July 07, 2019, 09:33:06 AM
Thank you guys for the tips. The bike is literally twice my age and I don't have the know-how or the place to work on it myself. Can anyone recommend someone local to the Los Angeles area to help me out and give me the opportunity to learn more?
Thanks
Armen


Title: Re: Idle issues + poor responsiveness
Post by: ryanschoebel on July 07, 2019, 10:26:35 AM
It seems a daunting task, but honestly, these bikes are amazingly easy to work on. While I'm sure there are a lot of members willing to help you out and show you, the best way to learn is to honestly just watch a few videos, get a Haynes/Clymer manual, and just open the damn thing up. you'll be surprised at how much you are able to accomplish. I am just a few years older than you, and within a year of owning an FJ, I was comfortable enough to drop the engine out of frame, among many other things. Start small, do research, and ask questions!


Title: Re: Idle issues + poor responsiveness
Post by: Tuned forks on July 07, 2019, 11:16:23 AM
+1 on Pat's advice to send the carbs to Robert at RPM.  We have nothing to gain financially by making this recommendation but many or most of us active on this forum have benefitted from Robert's carburetor work.  If you can't afford it, then ask on this forum how to rebuild them yourself but RPM's work is top notch.  Your engine will run sooo much smoother.  You could also caravan up to Oakdale this Oct for the RPM Fall Rally with the other SoCal members.  Look in the Rally section for further information on that event.  There are at least a few members that come up from SoCal, Pat being one of them.

+1 also on the 1000 rpm idle speed although since Robert's work my engine comfortably idles about 750 rpm.

Joe


Title: Re: Idle issues + poor responsiveness
Post by: Pat Conlon on July 07, 2019, 11:19:11 AM
Armen, Monkey Mark is in your neighborhood...stand by and he will chime in.

What I have noticed is that many motorcycle shops no longer work on carbs. It seems like the young service techs are not trained on the intricacies of a Constant Velocity Mikuni Carb.

For folks who do not wish to fuss with carbs, we are fortunate to have RPM to send our carbs to.

Meantime: Don’t store your bike with E10 crap fuel in the tank and carbs.
https://www.samscycle.net/Storage-warning-local-gas.html (https://www.samscycle.net/Storage-warning-local-gas.html)


Title: Re: Idle issues + poor responsiveness
Post by: Tuned forks on July 07, 2019, 11:30:46 AM
Meantime: Don’t store your bike with E10 crap fuel in the tank and carbs.
https://www.samscycle.net/Storage-warning-local-gas.html (https://www.samscycle.net/Storage-warning-local-gas.html)

Hmmm, to easily do this on the fuel pump models, we would have to add an electrical switch to the fuel pump circuit.  Not a biggee and as a matter of fact I did it for the FZR.  Perhaps SF's cool weather has helped me not have the problem on the FJ but I suppose a three way switch is a good idea.

Joe


Title: Re: Idle issues + poor responsiveness
Post by: Pat Conlon on July 07, 2019, 12:02:43 PM
Joe, did you want this post here? ^^^

If not, let me know where you want it and I’ll move it for you...


Title: Re: Idle issues + poor responsiveness
Post by: Tuned forks on July 07, 2019, 12:06:08 PM
Pat I was making the point, regarding your link, that to drain the fuel from the latter fuel pump FJ's would require turning off the pump and running the engine until the carbs are dry.  On my bike, I can't reach the petcock without raising the fuel tank up.

Joe


Title: Re: Idle issues + poor responsiveness
Post by: Pat Conlon on July 07, 2019, 12:37:43 PM
Gotcha...

Although, turning off the gas and running the engine until it stalls will not get *all* the fuel out of the fuel bowls (just down to the level of the pilot jets) Whatever is left will turn into a green jelly.
(https://www.samscycle.net/0_0_0_0_302_404_csupload_66963356.jpg?u=1167445689)


Title: Re: Idle issues + poor responsiveness
Post by: RPM - Robert on July 07, 2019, 04:42:26 PM
Whatever is left will turn into a green jelly.

And Pat has first hand experience with the green carbs. :Facepalm:

These were his carbs following the winter 2012 storage.


Title: Re: Idle issues + poor responsiveness
Post by: Pat Conlon on July 07, 2019, 05:44:24 PM
Yea, I remember that...

E10 came out in Calif. gas in 2010, so that looks about right for 2012....we were still learning....


Title: Re: Idle issues + poor responsiveness
Post by: 1tinindian on July 07, 2019, 05:55:24 PM
I hear if you run a tank of 100LL through the bike before storing it, that these sort of problems are well reduced.


Title: Re: Idle issues + poor responsiveness
Post by: Pat Conlon on July 07, 2019, 06:01:01 PM
What's 100LL?

AV gas?


Title: Re: Idle issues + poor responsiveness
Post by: Tuned forks on July 07, 2019, 06:11:17 PM
I think it's 100 octane low lead Av gas Pat.

Joe


Title: Re: Idle issues + poor responsiveness
Post by: Pat Conlon on July 07, 2019, 06:15:53 PM
I bought a 5 gallon can of VP C9 race gas...that purple stuff works great.
https://vpracingfuels.com/product/c9/
It evaporates nice and clean out of my fuel bowls durning hot summer storage.


Title: Re: Idle issues + poor responsiveness
Post by: Tuned forks on July 07, 2019, 07:29:27 PM
Alternatively, Rainbow Agricultural sells 5 gal cans of alcohol free gasoline.  Works outstanding in the little engines like chainsaws, trimmers, Briggs & Stratton, etc.  I assume it would work in our motorcycles too.

Joe


Title: Re: Idle issues + poor responsiveness
Post by: 1tinindian on July 07, 2019, 09:01:37 PM
What's 100LL?

AV gas?

Like the other fellas have said, yes, it is what used to be called AVGAS, from back in my Air Force days, that is what we called it, but now it's called 100 low lead, in the same way how we were used to JP4, it's referred to JET A now.


Title: Re: Idle issues + poor responsiveness
Post by: ArmArak on July 07, 2019, 11:12:18 PM
So where can I get some of that 100LL and what would be the appropriate mix ratio with regular gasoline?
Thanks
Armen


Title: Re: Idle issues + poor responsiveness
Post by: balky1 on July 07, 2019, 11:53:50 PM
So where can I get some of that 100LL and what would be the appropriate mix ratio with regular gasoline?
Thanks
Armen

I run pure 100 octane gasoline (be aware that US and EU express octanes differently, but maybe 100 is 100 on both sides), no need to mix it.
What is the highest ethanol content fuel that you guys ran in FJ?


Title: Re: Idle issues + poor responsiveness
Post by: Pat Conlon on July 08, 2019, 12:14:46 AM
So where can I get some of that 100LL and what would be the appropriate mix ratio with regular gasoline?

Last I checked, AVgas was available at a FBO (I’m having fun letting the new guy figure that one out)

No mix ratio, you want to replace all your fuel with 100% ethanol free fuel.
I don’t have to worry about tank condensation in my dry desert region so I just keep 2 gallons in my tank.

Again, this is for storage....if you ride every other weekend, you’re fine with E10 fuel.



Title: Re: Idle issues + poor responsiveness
Post by: 1tinindian on July 08, 2019, 07:52:28 AM
100LL is colored blue!
Looks like washer fluid!



Title: Re: Idle issues + poor responsiveness
Post by: ArmArak on July 08, 2019, 02:36:30 PM
So i guess I need to have my carbs cleaned but I unfortunately don't have the space nor the experience to do it (even though I would love to learn some time). How can I contact Robert from RPM so I could send the carbs to him for a pro cleaning?
Thanks
Armen


Title: Re: Idle issues + poor responsiveness
Post by: Pat Conlon on July 08, 2019, 02:58:38 PM
Call him
http://rpmracingca.com/contact.html (http://rpmracingca.com/contact.html)


Title: Re: Idle issues + poor responsiveness
Post by: racerrad8 on July 08, 2019, 05:14:46 PM
How can I contact Robert from RPM so I could send the carbs to him for a pro cleaning?
Thanks
Armen

Armen,


You can call the shop during business hours M-F. We head out for lunch on some days and have to pick-up & deliver parts as well. So, if you don't get an answer leave a message and we can call you back.

Secondly, feel free to send an email if that is more convenient.

You can find the contact info on the link Pat posted.

We will get you dialed in and on the road.

Randy - RPM