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General Category => Yamaha FJ1100 / FJ1200 Running Problems => Topic started by: Urban_Legend on September 24, 2016, 08:01:14 PM

Title: Running Diagnosis
Post by: Urban_Legend on September 24, 2016, 08:01:14 PM
I All.
I know there would be a solution to my running issues on the forum somewhere, but I am having trouble finding it.
So here it is -
I Changed me needle settings the last week to richen up my fuel mix and instantly the bike became really hard to start, so I returned them to previous settings, no change. Still won't start easily.  :diablo: Then yesterday on a group ride the bike gradual started to have running issues, until at the end of the day it sounded like it was running on 3 cylinders at idle and was popping and farting, except under acceleration. She was sounding really sick.  :bad:

my Settings are -
Fuel mix screw 2 1/2 turns out
Needle on third groove.
Jets are as standard for an 1100
Pod Filters and
4-1 pipes.
I know with the setting I have the bike will be running lean, and I do have bigger jets on the way (whole carb bank actually from a 1200)

Any help please  :dash2:

Mark
Title: Re: Running Diagnosis
Post by: Pat Conlon on September 24, 2016, 08:12:42 PM
Plugged pilot jet(s) plugged idle and choke circuit. Emulsion tubes (aka needle jets) clean?
Title: Re: Running Diagnosis
Post by: Urban_Legend on September 24, 2016, 08:16:20 PM
It is always a possibility is got some crud in them when doing the adjustments.  I don't have a closed in shed and it was a windy day.
Title: Re: Running Diagnosis
Post by: Urban_Legend on September 24, 2016, 10:59:59 PM
I found part if the issue.  The vacuum cap on number one must have blown of when the bike backfired. That will cause the rough running.  Now to fix the hard starting.
Edit. Not sure why photo is upside down. Sorry
Title: Re: Running Diagnosis
Post by: Urban_Legend on September 24, 2016, 11:41:01 PM
Cleaning out the  carbs and installing some jets that I had completely forgotten about. 42.5 and 115. We will see how that goes. The emulsion tubes look good for their age.
Mark
Title: Re: Running Diagnosis
Post by: Bones on September 25, 2016, 01:07:30 AM
All I did to mine Mark after fitting pods was lowering the clip one notch to raise the needles. Apart from that everything is standard fare for a 93 model, it starts easy, runs good at low revs and accelerates hard. The book says 3 turns out for the mixture for my model, but at that setting it hunts at idle like a lumpy cam and it's jerky to ride at low revs so I've turned them out to around 4 turns which smooths everything out. Once everything's cleaned, sync'd and running good, I tend to leave them alone because the more you fiddle with them the more they seem to play up.
Title: Re: Running Diagnosis
Post by: Urban_Legend on September 25, 2016, 04:14:24 AM
Hi Bone

I know what you mean. Problem is that I like to tinker.
I have gotten the bike to start now, but running way too rich (blowing black fuel smoke) and not wanting to idle  :wacko3: Will drop it bake to 40 main jet tomorrow and see how we go.

Ta
Mark
Title: Re: Running Diagnosis
Post by: oldktmdude on September 26, 2016, 07:22:27 AM
   Mark, you may have a fouled plug or two. Slip some known good plugs into her and fit clean #40 pilot jets. Mixture screws out 2 1/2 - 3 turns.
   Regards, Pete.  :good2:
Title: Re: Running Diagnosis
Post by: Urban_Legend on September 26, 2016, 07:29:44 AM
I put the 40's back in. Made.sude they were clean. Bike wound over, but not start. A few really good backfires though.  The carbs are squeaky clean now too. Going by the carb sync gauges the motor seems to have good suck still, so I am thinking it is not the valves.
Title: Re: Running Diagnosis
Post by: MOTOMYSZOR on September 27, 2016, 01:57:07 PM
When You richen up mixture it could kill spark plugs. Especially if You start engine just for a while to check everything.

Just check them closely......
Title: Re: Running Diagnosis
Post by: Urban_Legend on October 01, 2016, 09:58:21 PM
Arrr help. Still won't start. But getting an ALMIGHTY backfire. I have everything set to where is was running before, with the exception of some new diaphragms.
Mark
Title: Re: Running Diagnosis
Post by: Urban_Legend on October 01, 2016, 11:09:26 PM
Would the dreaded melted red plug, make the bike hard to start,  or is it only a charging issue.
Title: Re: Running Diagnosis
Post by: FJmonkey on October 01, 2016, 11:14:32 PM
A low battery will not help with a hard starting issue. Looks like a small thermite grenade went off in your connector.
Title: Re: Running Diagnosis
Post by: Urban_Legend on October 02, 2016, 02:37:46 AM
 Looks like a small thermite grenade went off in your connector.

More like a bloody huge one. I fixed the offending connector and managed for get some life out of the bike. It is running , but not well. Fining it damn near impossible to balance the carbs with my cheap gauges. So I made an executive decision to take it to someone who knows what they are doing on Tuesday (public holiday here on Monday) to get it running right. No wonder a man drinks.  :flag_of_truce:
Title: Re: Running Diagnosis
Post by: Urban_Legend on October 07, 2016, 12:00:31 AM
Hi All

An up date on my running issues

After removing and cleaning the carbs (many times), changing jets and changing them back and fiddling with mixture screws and much swearing and consuming of beer, I finally gave up and took the bike to my local bike shop. They started off much the same as me, and event thought it was the CDI after diagnosing a loss of spark, which really through the mechanic as he had the bike running. Finally he traced the spark issue to a loose bolt in the crank angle ignition set up. The bolt was shorting out the pickups and causing all of the running issues.

Bike happy again.

Mark
Title: Re: Running Diagnosis
Post by: FJ_Hooligan on October 07, 2016, 11:42:57 AM
Wow!  What an unfortunate coincidence. 

Glad you got it fixed
Title: Re: Running Diagnosis
Post by: bigbore2 on November 07, 2016, 01:35:36 AM
Had the same problem with my bike this year, just could not get it to run well at 2000 rpm and under.
Had an ignitor go bad, my shop diagnosed that. Replaced that and got a little riding time but the same problem came back. Took it back, my shop did not know what was wrong.  Took it to another shop and for only $600, I could get it fixed. They told me it was a carb problem and would find it, fix it and power tune the engine.

While I was having this problem, every once in a while it would work perfect. My 1100 engine is just such a great engine. I just needed it to work like that all the time. So I decided to go thru the carbs 1 more time, as I was the one who rebuilt them 4 years ago, no issues whatsoever until now. If I could not get it, off to the shop.

Everything was clean as a whistle as I used a magnifying glass to really look.  Found a bent float pin that was not letting the fuel needle seat on #3 carb. fixed that and that solved my issue. Now that engine is sweet EVERY time I ride it.

I just wanted to post this, because several times during this problem, I wanted to give up , sell the bike and get another bike. But I latched on to the idea of, if this engine ran the way it is supposed to, like I read ALL you are doing, I will love this bike. This forum helped me a lot, and I did not want to lose my membership/by selling my bike either.

So thanx to our little forum and you members, I now have a great bike to enjoy.