Bike won't hold idle

[Topspeed]

Just got my fjr back from the 26k valve check. Which ended up being a valve adjust because 6 of the intakes were at the very bottom of the range. Riding the bike home after words, I had the bike stall on my 2-3 times when coming to a stop. I wasn't too worried because I figured I was being hamfisted after being on a borrowed VFR for the last week and a half. However, this morning while getting ready for a ride I started the bike and was checking the tire presssure and the idle was fluctuating up and down a little (like maybe 100 rpms or so), but then the idle started to drop to 500 and... she died. I started her up again and... she died.

The tech did say that after the valve adjust he had something similar happen, so when he called Yamaha they told him to make sure all the throttle bodies were adjusted to 250 mg and then synch, which he said he did and the problem disappeared. Obviously, not completely though. So, any ideas on what the problem is/might be?

Topspeed

 

[03HiYoSilver]

Topspeed,

Lift the tank and make sure ALL the Vacuum caps are in place and/or not cut. This could be your simple solution.

 

[Topspeed]

All right, Silver, did that. All are in place and whole. Any other ideas?

*edit* idle lowers as the bike approaches normal operating temp (3-4 bars)

 

[madmike2]

Is the idle set @ 1100 rpms when hot?

It sounds to me the like the dealer gave you back a bike that's not ready to ride. What did they not do correctly?

 

[Topspeed]

it will idle at 1100 for a short while before it starts to fall. I'm also now hearing what sounds like vibration or a rattling behind the right side engine cover. Can't hear it while idling but as the revs increase so does this noise, until 3k RPMs or so then it disappears.

 

[madmike2]

Not a good sound. IIRC, that's the noise the cam chain tensioner makes. Is it possible they didn't get it back in place when they reinstalled the cams?

cam chain tensioner site:fjrforum.com

CCT site:fjrforum.com

 

[Topspeed]

I really hope not because I rode the bike 80 miles back from the dealer. Hope that hasn't made things worse. Guess its time to stop messing around with it and take it back for them to check out.

 

[FJRBluesman]

When my Gen1 drops below 1K or 900RPM, it makes a nasty noise but it's more clutch basket noise of the engine not rotating well, so the back slap makes a rather ugly sound. At 1100RPM it's fine. When the idle is low, pull in the clutch to see if the noise goes away, if not look into CCT. It's really an easy replacement if need be done, check out MM2's links to get tons-O-info on this. Here's my post on it.

 

[Queensland Ken]

Just got my fjr back from the 26k valve check. Which ended up being a valve adjust because 6 of the intakes were at the very bottom of the range. Riding the bike home after words, I had the bike stall on my 2-3 times when coming to a stop. I wasn't too worried because I figured I was being hamfisted after being on a borrowed VFR for the last week and a half. However, this morning while getting ready for a ride I started the bike and was checking the tire presssure and the idle was fluctuating up and down a little (like maybe 100 rpms or so), but then the idle started to drop to 500 and... she died. I started her up again and... she died.
The tech did say that after the valve adjust he had something similar happen, so when he called Yamaha they told him to make sure all the throttle bodies were adjusted to 250 mg and then synch, which he said he did and the problem disappeared. Obviously, not completely though. So, any ideas on what the problem is/might be?

Topspeed

Hi topspeed,

I've just had similar problem, check my post here https://www.forum.fjr13.org/viewtopic.php?f=7&t=1548 Aus forum site.

Just did a 70K Km valve check, all the things I did are on page 2. I was thinking it was a TPS failure ?

I'm still scratching my head.

Let me know what you find please.

regards

Ken

 

[03HiYoSilver]

Topspeed,

It sounds like the dealer did not perform the job correctly. I would contact Yamaha Customer Service and have the Regional Technical Supervisor take a look at it with you before any future damage may occur.

800-962-7926 Yamaha Customer Service

Hope your find your solution.

 

[HaulinAshe]

Topspeed,

Don't run the bike. Definitely follow the advice given and get in touch with Yami immediately. Your bike should be towed and inspected.

The dealer may have misadjusted the intake valves, but more likely it does sound like a cam chain tensioner problem. They may not have it properly released or it may be defective. In either case, things could get very ugly, very quickly.

Err on the side of caution with this one, and please let us know how things turn out for you.

 

[radman]

A bad throttle body synch can cause this. Also can cause a hunting idle. For what it's worth, I had 2 intakes at the tight limit last valve check, so adjusted for more gap. Listened to light cold tap for 20k, redid last winter, they hadn't moved a smidgen, so back to tight they went-all is good.

 

[Roy Epperson]

Just got my fjr back from the 26k valve check.
started to drop to 500 and... she died. I started her up again and... she died.

Topspeed,

I had the "exact" same problem. It was found bythe mechanic on the test ride. It ran fine until it got to normal temp and then died unless he added throttle. They would not let the bike go until it was corrected. He check the vacuum, TBS, etc all were well within spec. It turned out that the timing chain had shifted position by one tooth and the timing was off.

I got involved as he wanted to make sure how the Audivox was connected.

Roy

 

[Topspeed]

I ended up hauling the back back to the dealer on Monday; whoops I should have called first, they are closed on Monday (did I mention it was an 80 mile drive--one way :-0 ). Tech just called today and informed me that the timing chain been one tooth off, or was it there some sort of chain attached to the exhaust valves and that was off one? I was half asleep when he called will find out for sure tomorrow when I pick the bike up. They even went so far as to have all the mechanics in the shop do their own inspection after today's work was done to make sure it was correctly lined up this time. No damage was done according to the shop. Oh yeah, they carefully checked over the CCT as well and said all is good. It's too late now to pick it up today, will have to find the time tomorrow. Thanks for all the help guys.

Top

 

[Roy Epperson]

Tech just called today and informed me that the timing chain been one tooth off, or was it there some sort of chain attached to the exhaust valves and that was off one?

Told ya Glad that was the problem! My mechanic said he had another one happen to him many years ago on a different Yamaha. He showed me the timing marks and it would be an "easy" miss if you didn't take a very close look.

Get out and ride before that white stuff start falling!!

 

[03HiYoSilver]

Topspeed,

Glad they found the problem and it is all worked out for you.

Thanks for letting us know.

All the best.

 

[wfooshee]

Of course what that means is that they didn't time the cams correctly after changing shims, something the mechanic should have checked, double-checked, and checked again before buttoning it up and releasing it. It didn't slip a tooth anywhere, it was put back together wrong.

Glad it's fixed, though, for sure. Scaring us with that "noise from the right side cover" ****.

 

[FJRBluesman]

All - Take note.... A happy ending that could have been tragic.

To all those nay sayers....

 

[Fred W]

Good to know that you can F### up the timing by at least one tooth and not cause engine carnage.

Also would be good to know the dealer's name to avoid using them in the future. I'm just sayin'... Of course, it's not for me. I don't get service in UT very often...

On a slightly different tangent: If a valve measures "at the limit" it is still in spec. Following the KISS principle of not fixing what ain't broken, I would not reshim valves that are still within spec unless I found one that was actually out of spec. The tolerances are narrow enough to accommodate normal wear between valve checks in the maintenance schedule.

Specs for the FJR are .15-.22mm Intake, .18-.25mm Exhaust, which is often (loosely) translated to .006-.009" Intake and .007-.010" Exhaust. Normally, as valve seats wear their measured tappet clearance decreases. If you can still fit a .006 feeler in the intakes, or a .007 in the exhaust they should be OK until the next check.