Rough Idle at startup

AStar · Feb 8, 2009

Myself and others have posted the problem of 06 through 09 running rough at startup and continuing until the bike gets warm.

Several have reported the problem after the 600 mile service. My dealer could not solve the problem and I think that it is time that we hit the dealers and Yamaha Techs with the problem. What I would like to do at this point is gather information to show numbers to the dealer and Yamaha about a problem that is not solving itself.

In my case I have an 07 FJR A model with low miles and at startup it runs very rough and makes clunk sound when one of the cylinders misses. It does this until the bike gets about two bars on the temp graph and the idle slows. I changed the plugs and took the bike to the Dealer who checked injectors to vaccum to spark and compression. What I would like to get from the forum is a list of bikes that are experiencing the same problem. Now if someone has figured it out and has a fix already I am all ears.

But I would like to Get Year, Model, and Vin if you are comfortable with that.

Mine. 2007 FJR 1300A Vin: JYARP15E67A002090

Thanks for your help.

YooperDick · Feb 8, 2009

FJR 1300A VIN: JYARP15EX8A005169

SkooterG · Feb 8, 2009

Interesting. My 164k 04 FJR makes that 'clunk' during fast idle too. Though it doesn't idle rough. It's only been doing that for the last 20k or so - not ever doing it for most of the bike's life.

radman · Feb 8, 2009

The "clunk" isn't really a clunk at all, it's a muffled "pop" from a lean misfire, coupled with the resulting misbalance produced from the momentarily dead hole. The mixture tends to be a bit on the lean side while in open loop cold motor mode so as to not flood the motor-with separate TB's and short paths, too rich a mix would result in a lot of liquid fuel condensing on the metal along the mixtures path, so it's a real ballet to produce a rich enough mix so the engine will run cold, yet lean enough to not flood and/or dump raw fuel in excess of what the engine can burn. Even so, the FJR does tend to be rich enough to cold start flood rather easily, and on short trip motors (even to a degree those ridden for longer periods) oil dilution is a real issue with them. This is one of the reasons I change oil far more often than many. The Barbarian deals with the cold pop/roughness somewhat with it's overall richer mixture throughout the rpm spectrum. The cold start map is locked in the ECM, no altering that-open loop uses set parameters that do not involve the various sensors other than temp-once it indicates a warm engine, of course, the ECM is in closed loop. I don't know that a PC does much for cold start mix as most maps have no enrichment at idle rpms-but they do at 1200-1500 up. I believe the PC helps somewhat even without TPS input, as part of it's process involves enrichment using rpm's as an input. Honestly, I don't see the pop/roughness as a problem, as it only is evident the first 2 minutes or so of the engines running, a very small part of a days ride.

fjrshanta · Feb 8, 2009

radman said:
The "clunk" isn't really a clunk at all, it's a muffled "pop" from a lean misfire, coupled with the resulting misbalance produced from the momentarily dead hole. The mixture tends to be a bit on the lean side while in open loop cold motor mode so as to not flood the motor-with separate TB's and short paths, too rich a mix would result in a lot of liquid fuel condensing on the metal along the mixtures path, so it's a real ballet to produce a rich enough mix so the engine will run cold, yet lean enough to not flood and/or dump raw fuel in excess of what the engine can burn. Even so, the FJR does tend to be rich enough to cold start flood rather easily, and on short trip motors (even to a degree those ridden for longer periods) oil dilution is a real issue with them. This is one of the reasons I change oil far more often than many. The Barbarian deals with the cold pop/roughness somewhat with it's overall richer mixture throughout the rpm spectrum. The cold start map is locked in the ECM, no altering that-open loop uses set parameters that do not involve the various sensors other than temp-once it indicates a warm engine, of course, the ECM is in closed loop. I don't know that a PC does much for cold start mix as most maps have no enrichment at idle rpms-but they do at 1200-1500 up. I believe the PC helps somewhat even without TPS input, as part of it's process involves enrichment using rpm's as an input. Honestly, I don't see the pop/roughness as a problem, as it only is evident the first 2 minutes or so of the engines running, a very small part of a days ride.

Ok! now, can you get a bit more detail. I think ya just hit the basics.

Nice bit of info!!

AStar · Feb 8, 2009

radman said:
The "clunk" isn't really a clunk at all, it's a muffled "pop" from a lean misfire, coupled with the resulting misbalance produced from the momentarily dead hole. The mixture tends to be a bit on the lean side while in open loop cold motor mode so as to not flood the motor-with separate TB's and short paths, too rich a mix would result in a lot of liquid fuel condensing on the metal along the mixtures path, so it's a real ballet to produce a rich enough mix so the engine will run cold, yet lean enough to not flood and/or dump raw fuel in excess of what the engine can burn. Even so, the FJR does tend to be rich enough to cold start flood rather easily, and on short trip motors (even to a degree those ridden for longer periods) oil dilution is a real issue with them. This is one of the reasons I change oil far more often than many. The Barbarian deals with the cold pop/roughness somewhat with it's overall richer mixture throughout the rpm spectrum. The cold start map is locked in the ECM, no altering that-open loop uses set parameters that do not involve the various sensors other than temp-once it indicates a warm engine, of course, the ECM is in closed loop. I don't know that a PC does much for cold start mix as most maps have no enrichment at idle rpms-but they do at 1200-1500 up. I believe the PC helps somewhat even without TPS input, as part of it's process involves enrichment using rpm's as an input. Honestly, I don't see the pop/roughness as a problem, as it only is evident the first 2 minutes or so of the engines running, a very small part of a days ride.

I can say that my 05 never made the noise or run rough at startup. I do not understand why some bikes run rough at startup and others like my first 05 run fine. I would like Yamaha to come up with an answer and fix it if possible. To me it is more than a little annoying.

SkooterG · Feb 9, 2009

radman said:
Honestly, I don't see the pop/roughness as a problem, as it only is evident the first 2 minutes or so of the engines running, a very small part of a days ride.

Thanks for the most excellent reply rad! I wasn't too concerned about it which is why I never mentioned it here, and figured that since it was only during warm up not too big a deal. But it's great to have some validation.

I figure with 164k on the clock I am going to hear some new sounds, feel some new vibrations every once in a while.

odot · Feb 9, 2009

Skooter...you won't feel any other vibrations other then that 12 volt powered "thingy" you installed when you first bought the skoot.

AStar · Feb 9, 2009

There were alot more members out there that chimed in before when this subject came up in September of 08. Don't be shy now.

TahoeBound · Apr 1, 2009

AStar said:
There were alot more members out there that chimed in before when this subject came up in September of 08. Don't be shy now.

Same problem here with my '08 Kali version. It has happened since new (though my '04 never had problems). It chokes/burps/hesitates when first started (sometimes 4+ times) but never dies. After warmed/ridden it is fine. "Seems" to burp more lately since I've added a larger AVCC vacuum cannister & did a TBS - but hopefully thats just my mind playing tricks. I'd like to do the Barbarian mode to see if that helps.

Ramblin Man · Apr 6, 2009

Try pluggung the hose that runs from the airbox to the exhaust reeds on top of the valve cover and see if that helps.

Rough Idle at startup

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Rough Idle at startup

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