Rough Running and Hard to Start When Hot--Again

[SacramentoMike]

And I mean when the bike is hot, not the ambient temp. On my recent long trip around the country I had two episodes where the bike would not start, and at least once more when starting seemed iffy but it did start. Normally, of course, the bike just cranks over powerfully and starts right up, but on these two occasions it felt as though the battery was very weak and it couldn't crank hard enough to fire. Both times I did get it running by just waiting a few minutes, but it's never comfortable when you're thousands of miles from home. My WestCo battery was new in March of '13.

When this happened, it always followed a period of low-speed putting around sightseeing, starting and stopping, etc. In addition to not starting, it ran very rough for a while, at least while the temp gauge was high, and/or had been running rough before the starting failure. Every time it happened, a few miles at higher speeds (enough to bring the gauge down to a couple or three bars) helped and the bike ran fine again. The second time it wouldn't start, in Ithaca NY, I found a nearby battery dealer since I thought that seemed a likely source of the problem. He didn't have an exact fit, but was nice enough to help me get my battery out and it tested as "good" on his machine. Hmmm. Still, a couple days later, riding slowly through the battlefield at Gettysburg and stopping to read monuments and signs, it began running bad again--very rough. I'm sure if I'd shut it down then it would have been hard or impossible to start.

After that, BTW, I haven't had any further problems at all, but it still leaves me kind of uneasy. I looked through existing "hard to start" threads, but didn't see a real good match--especially the part about the rough running combined with the starting issue. There was some speculation on one thread that the starter switch could be involved in the problem, but, but sorry, I couldn't find that thread. Do any of you have any direct knowledge of a similar situation and especially, what was done to correct it? Thanks.

 

[Greg 03]

Does your bike fall under the TPS recall and was it done?

 

[BigOgre]

Related to the starter maybe? Although the rough running before shutting it down adds a twist. Here's a link to a recent thread which might be the one you were thinking about with the starter switch. Good luck.

 

[rogdeb]

Mike,

What happened to you is exactly the same problem I had a few years back. Always when temps were above 90 and always when I tried starting the bike, after a 10 to 20 minute break, after running for an hour or so.

If the bike was sitting in full sun during that break, the problem was more severe.

Stumbling occurred for approx 5 minutes then cleared.

Never found out why it happened, and hasn't happened for a number of years since. Go figure ??

 

[Queensland Ken]

Strange !

Was recently working on a mates bike with similar symptoms.

Was a petrol tank vapor lock caused by a valve in the CA model pollution stuff, that valve that's near the charcoal canister.

The FJR as an import into Australia from California, don't see too many of them here, not alone that fault.

The tank breather hole is under the screw head at the 9 o'clock position.

Make sure there is a short screw in that position.

When it shows the symptom, open the tank up and see if there is any pressure built up.

 

[supertankerm60a3]

OK, it looks like it has this problem only when it is VERY hot. Next time, try cycling the key on and off several times. My theory is: When you shut it off hot, the fuel is boiling in the fuel rail and causing fuel starvation upon restart. So cycling the key several times should build up the fuel pressure and purge any trapped vapor because the fuel pump comes on for a second every time the key is turned on. At best it will start and you will know the cause, at worst, you haven't lost anything.

 

[HotRodZilla]

Wasn't this a documented battery issue a while back? If I read it right, the starter lugs like the battery is dying. Not a fueling issue, and not a switching or TPS issue. It's possible the starter is taking a dump. Also, good test or not, I gotta wonder about the state of your battery, especially since the slow speed, low revving riding is when the symptoms start.

Might wanna see if Iggy still has that on his '05 he's parting out, but I'm seriously betting battery.

 

[supertankerm60a3]

Starter full of oily conductive carbon pudding could be an issue inside the starter. That has been found on this forum multiple times. Getting to the starter can be a pain though.