Rough idle

[rusty1]

Hello

can anyone offer help on this intermittent problem?

rough idle
down to what sounded like 3 cylinders
turned bike off, would not start again
battery seemed flat

fitted new battery
bike idled fine
went for long run came home parked up.
started next day and was fine.

started 2 days later - back to the intermittent running.
in addition, the rev counter stopped while on idle and the temp flashed HI
when you turn the bike off the temp was 67degrees and the rev counter worked but the rough idle STILL there.

I have used 2 tanks of fuel additive cleaner, put a new battery in and the bike still runs on what sounds like 3 cylinders - not smooth and down on power.
Intermittently. I could go out now and it might be fine on idle....

thoughts?

regulator/plugs?

SOOOO annoying lol

thanks in advance:rockon:

 

[TownsendsFJR1300]

Hello

can anyone offer help on this intermittent problem?

rough idle
down to what sounded like 3 cylinders
turned bike off, would not start again
battery seemed flat

fitted new battery
bike idled fine
went for long run came home parked up.
started next day and was fine.

started 2 days later - back to the intermittent running.
in addition, the rev counter stopped while on idle and the temp flashed HI
when you turn the bike off the temp was 67degrees and the rev counter worked but the rough idle STILL there.

I have used 2 tanks of fuel additive cleaner, put a new battery in and the bike still runs on what sounds like 3 cylinders - not smooth and down on power.
Intermittently. I could go out now and it might be fine on idle....

thoughts?

regulator/plugs?

SOOOO annoying lol

thanks in advance:rockon:

If you have a volt meter, you need to check the voltage across the battery terminals. (I'm assuming the terminals are clean and tight). There should be about 12.8 volts sitting (not running-fully charged) and when revved up to 5K RPM's it should be putting out 14.1-14.9 volts per my 07 Yamaha shop manual. The engine really doesn't charge at idle, its designed to have some rev's to re-charge the battery..

You bike sounds like its not charging the battery. With a fresh battery its running off the battery. Once the voltage starts going down, so does the performance. Idleing isn't helping any..

Once you determine that we can go from there...

 

[rusty1]

OK cool, will try and get a meter over the weekend.

Thanks for the reply :thumbup:

 

[rusty1]

UPDATE:

I bought a multi-meter and measured the voltage.

12.7v from battery when turned off

14.6v when bike turned on and revved to approx 5,000rpm

I still have this rough '3 cylinder' type of idle. It only happened when the bike warmed up, when cold it was OK. This maybe just coincidence as it has been rough idle on cold start up previously.

I removed the plugs, cleaned them and checked a spark was going to all of them which there was. Therefore I am assuming the plugs and HT leads are OK.

My thoughts are dirt in the injectors - the top of the tank inside the petrol cap has rust - could this be blocking an injector? I have put 2 bottles of petrol injector cleaner through it though.

Could it be a 'weak' spark if there is such a thing?

Could the rectifier be intermittently shorting?

I looked for frame/wire shorts in the dark and could not see sparks. The rectifier is very hot by the way??

Help!!!

 

[TownsendsFJR1300]

Sounds like the charging system is ok from what you state. If there's rust in the tank it is possible a small piece of crap got past the in tank filter clogging an injector. You need to get that rust out of there or you'll have further problems...

If you can get an infrared gun and measure the temps on the header as it comes out of the engine should give you an idea what cylinder may not be firing/not enough fuel, etc... A small spritz of water on each header pipe may work too but obviously isn't nearly as accurate..

I've read of several companies that cleans/re-furbishes injectors at a fraction of a new one if needed...

There are two coils, you can check them, I'm getting ready to e-mail the manual.


***What year bike is it? There was a re-call on the TPS for the 04 and most 05's which will cause running problems, especially low end. Its a free fix. For more info:

http://www.600riders.com/forum/fz6-...ou-experiencing-poor-idle-mileage-stalls.html

 

[rusty1]

Thanks Scott.
Bike is 2007

I guess it is process of elimination

 

[Jacobien]

What about going into the DIAG mode? If the bike displays errors as they appear, what I think it does, I am sorry if I just wasted a minute of your time...

Worth a check anyway, then that bit is eliminated.

 

[TownsendsFJR1300]

I re-read your first post and have some other thoughts/possible fixes...

With the problem coming and going and some electrical issues, I'm tending to lean towards a bad ground/connection somewhere. I personally would start un-plugging/cleaning and put Dilectric grease in all connectors. Any corrosion found can cause havoc. Check the main plug to the ECU as well. I don't think the injectors are clogged if the bike runs great sometimes and crappy other times. If its clogged and stays clogged, it'll run crappy 100% of the time. Also, check the readings of the ignition coils besides cold, but also WARM. You can use a hair dryer to warm it up or even do it with the bike running (I'd put a fan blowing on the radiator, etc to keep from over heating) and see if you can replicate the problem

The handlebar kill switch is known to fail (bad connection) so you might try, with the bike running, manipulating it some and see of you can get the problem to arise. It wouldn't explain your dash outputs thou...

(In my FJR, several years ago, the bike started running crappy. Brought it to the shop, had the TPS replaced((recalled)) and the throttles synced. Still had the on/ off hesitation(under warranty). I replaced the plugs with 6,000 miles on them. Found a thread on the FJR forum about one connector under the gas tank that likes to collect water/corrode.. Sure enough, it was corroded, not a lot, but some green. Cleaned it up, dilectric grease, runs like a champ again, been fine since, about 5 years ago. I could hear it as soon as I cranked it up.) Point being, just a little corrosion, especially on those tiny connectors nowadays can easily cause problems...

Motogiro should chime in here, he's real good with electrics...

 

[fizz_off]

Never mind (read the other symptoms - didn't exactly match mine).

 

[rusty1]

thanks guys, have been reading other threads and also noted the kill switch being a potential problem, and also a poor earth on the frame. I agree, I will check all connectors and clean tomorrow and feed back, its weird because when I removed the plugs, cleaned them and put back in she ran real sweet.

I thought I had cracked it, then when idling after about 5 mins she started going rough again???

I hope it's a simple fix, I already bought a rectifier off ebay before I got the multimeter and am reluctant to start buying coils, leads, plugs etc.

It's catch 22, try and fix it yourself and buy half a bike in the process or leave it to the 'stealer' and be charged a fortune labour lol

I'll update progress asap

thanks again for all replies :rockon:

What are the readings on the coils meant to be?

 

[TownsendsFJR1300]

thanks guys, have been reading other threads and also noted the kill switch being a potential problem, and also a poor earth on the frame. I agree, I will check all connectors and clean tomorrow and feed back, its weird because when I removed the plugs, cleaned them and put back in she ran real sweet.

I thought I had cracked it, then when idling after about 5 mins she started going rough again???

I hope it's a simple fix, I already bought a rectifier off ebay before I got the multimeter and am reluctant to start buying coils, leads, plugs etc.

It's catch 22, try and fix it yourself and buy half a bike in the process or leave it to the 'stealer' and be charged a fortune labour lol

I'll update progress asap

thanks again for all replies :rockon:

What are the readings on the coils meant to be?

I don't know off hand and I'm not home. Check the PDF manual I sent you, it'll be in there.. Sometimes, the coil will check out ok cold and when heated up, fail.... Just an FYI.


Check the simple stuff first...

 

[rusty1]

this rough idle issue it seems is directly related to the rev counter stopping and the temp reading indicating 'high'.

turn the bike off and back on and rev counter and temp work, let it idle and 2 out of 3 times the rev counter stops and the temp reads high.

does anyone know what component might lead to this happening?
cdi
coils
rectifier

def seems an electrical problem. I checked and cleaned connectors which didn't help.

 

[FinalImpact]

Heres a thought -
Unplug the gauge cluster as maybe the cluster has an issue?? Hindsight says this is not it as it uses serial data wire for data transmission to the gauge.

Off hand - you can't tell if a plug is bad by looking at it and because it fires in the open, doesn't mean it'll fire under the load of compression. A simple thing like a change in humidity can keep a weak ignition system from delivering the energy to the plug (moisture cause it to arc-over to ground). Do the water spritz test to the exhaust, the dead hole which is not firing will take longer to evaporate the water off. If they are all the same evap time, the misfire could be random. If its stays to one place swap the coils and see if the problem moves.

Is it 100% miss at all RPMs or is it only 3000 rpms to idle?

Another option is to lift the tank a tad so you can see the plug wires. Fire it off off in the dark of night and look for sparks jumping from the wires. use the spritz again on the plug wires. If it starts to misfire. The wires are bad. Replace the coils and wires. Eitherway I'd opted for replacing the plugs.

So what color was the arc from the plugs? White/purple or orange/blue? The later of the twos is not favorable = weak ignition system.

 

[rusty1]

thanks finalimpact

cylinder 1 header is colder to touch than the rest, took plug out again cleaned and reinserted but no change. I have ordered new plugs.

i will try to swap coils round to see if faulty coil/lead is problem.

dont see any spark or arcs at night unfortunately with fine mist spray.

confused as to how the rev counter/temp gauge stops working.

will update as parts come in:thumbup:

ps from recollection it seemed more lumpy below 3000rpm and sort of evens out as you give it more throttle but feels it is still underpowered if I am explaining this effectively?

 

[FinalImpact]

thanks finalimpact

cylinder 1 header is colder to touch than the rest, took plug out again cleaned and reinserted but no change. I have ordered new plugs.

i will try to swap coils round to see if faulty coil/lead is problem.

dont see any spark or arcs at night unfortunately with fine mist spray.

confused as to how the rev counter/temp gauge stops working.

will update as parts come in:thumbup:

ps from recollection it seemed more lumpy below 3000rpm and sort of evens out as you give it more throttle but feels it is still underpowered if I am explaining this effectively?

When you say you cleaned them; what was on them that needed cleaning? Was it all of them or Just #1? Did you by chance move plug #1 to another location and vs vrs?

And just to confirm; spraying the wires did not change how it runs?

So; if #1 needed cleaning as it smelled of gas because it wasn't firing and I had no other option but to put the plug back in the bike I would . . .
Take a small propane torch and heat the plug from the threads to cook and displace the unburned gas. The goal here is moderation and raising the temp to 250 - 350 degrees tops and allowing it to cool. When the porcelain stops smoking its usually dry but this is by no means a guarantee that it will fire.

OK - I hear ya on the meter not working and that is puzzling. The meter does some of the following all through a single wire so I want you watch closely to see if these are also affected: tach, speed, water temp, air temp, others??? What do they read when it faults out?

From that I would start with this; lift the tank and excersize every plug connection unlatching it and inspecting it. Try it again. If this doesn't work and you have known good spark plug in it (new), I would be very tempted to unplug the meter assembly. Also disconnect the battery for 10 min while you're there.

I'd also wipe the wires down with lacquer thinner just to remove any debris.

As for the running description - anything you can add helps but it sounds to be down on one cylinder all the time. You might just start looking for a compression gauge too. Other options to confirm how bad this is include unpluging one fuel injector at a time but we'll get to these options later after the coil swap.

 

[TownsendsFJR1300]

If you have a spare spark plug, plug it into the spark plug cap and crank the bike over making sure the plug is grounded to the head/block. Keep the #1 plug in the head. I want to know if your getting spark to the plug and work backwards. You can double check you plug by plugging it into your lawnmower engine(if you have one), ground the plug and pull. You should see a good spark...

As an FYI, the actually spark plug boot screws clockwise onto the wire itself. if it got pulled out (when pulling the spark plug wires) you may have loosened the connection and its arcing inside (between the wire itself and the cap). You can unscrew that cap (CC) and check for any carbon build up/arcing...