Jerky throttle and random idle

fz6blue

fz6blue

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Hi, Since getting back on my bike after a very long and cold winter I've noticed that its behaving very oddly. She starts up first time without any issues and seems to perform like normal for the first while. I have my idle set to 1400 which seems to work fine for my riding and usage. After 10 mins or so of a mixture of normal and spirited riding my idle speed is all over the place.. I've seen the idle at 2900 with my hand off of the throttle.. I've restarted her and she's fine again a second later! Other times the idle goes haywire and she seems to sort herself out again... today however she went from 2600 to 700 and started spluttering and farting to the point where I couldn't keep a stable slow speed. I've not seen the revs drop like that on their own before and so would appreciate any advice people can give even though she will have to go in to see the garage next week I think.

Also, I presume the snatchy throttle is more to do with a characteristic of an 04' FZ6 bike? Or is it linked to this issue?

Thanks
 
fz6blue said:
Hi, Since getting back on my bike after a very long and cold winter I've noticed that its behaving very oddly. She starts up first time without any issues and seems to perform like normal for the first while. I have my idle set to 1400 which seems to work fine for my riding and usage. After 10 mins or so of a mixture of normal and spirited riding my idle speed is all over the place.. I've seen the idle at 2900 with my hand off of the throttle.. I've restarted her and she's fine again a second later! Other times the idle goes haywire and she seems to sort herself out again... today however she went from 2600 to 700 and started spluttering and farting to the point where I couldn't keep a stable slow speed. I've not seen the revs drop like that on their own before and so would appreciate any advice people can give even though she will have to go in to see the garage next week I think.

Also, I presume the snatchy throttle is more to do with a characteristic of an 04' FZ6 bike? Or is it linked to this issue?
Thanks
Click to expand...

There was a wide spread issue with the throttle position sensor on the '04 model year. I have not had that issue, but this sounds like the behavior I have read of here. Someone should answer soon, with the procedure to check it out. If you search for TPS or throttle position sensor here, you should find a lot of references to it.
 
Thanks guys, have read the info about the TPS issue and I think my bike is part of the recalls for having it replaced by Yamaha. I'll book it in next week and get them to replace it and fingers crossed that will make the difference. Cheers for the advice and pointing me in the right direction! If replacing the TPS works I'll post back here to conclude the issue :)
 
A TPS failure shouldn't make your idle go as high as 2700 RPM. Sounds like you have some crap in your fuel system/fuel problem.

Did the bike sit for more than a month without fuel stabilizer? FI is not as sensitive as a carbed bike with bad fuel. If the fuel is old, I would siphon/dump the fuel out and add fresh fuel. I would also add some Chevron "tectron". Its a good fuel stabilizer and an excellent fuel system cleaner. Most automotive stores/Walmart carry it.. It'll take some time of running to with it to work...

I would also check the gas tank vent and make sure you don't have any kinks in the lines and that the vent is clear...

Wouldn't hurt to re-set the computer as well (disconnect the battery for a couple of minutes)..

Good luck..
 
Last edited:
TownsendsFJR1300 said:
A TPS failure shouldn't make your idle go as high as 2700 RPM. Sounds like you have some crap in your fuel system/fuel problem.

Did the bike sit for more than a month without fuel stabilizer? FI is not as sensitive as a carbed bike with bad fuel. If the fuel is old, I would siphon/dump the fuel out and add fresh fuel. I would also add some Chevron "tectron". Its a good fuel stabilizer and an excellent fuel system cleaner. Most automotive stores/Walmart carry it.. It'll take some time of running to with it to work...

I would also check the gas tank vent and make sure you don't have any kinks in the lines and that the vent is clear...

Wouldn't hurt to re-set the computer as well (disconnect the battery for a couple of minutes)..

Good luck..
Click to expand...

The bike was sitting for about 3 weeks without fuel stabilizer - I have covered a good 500 miles since then and a good few tanks worth of fresh fuel. I presumed that would have been flushed out by now?! My local Halfords doesn't seem to stock Tectron but they have other variants instead, is there much difference between them? This is the one I was thinking of picking up: Redex Petrol Treatment 250ml from Halfords Price £4.99 Free Redex Petrol or Diesel Treatment When You Buy Any Castrol Magnatec 4 Litre Oil

I'll get some fuel stabilizer today and give that try.

I have to admit I'm not a big fan of disconnecting the battery as its such a pain in the backside trying to wiggle those front plastic panels out from underneath the handlebars before getting the gas tank off. I'm sure there's a technique, but I haven't mastered it! I'll do that too though as I want to eliminate all possibilities.

Finally how do you check your vent lines? Do you pull them off and try to see light through them (I haven't looked at them yet so am not sure how they work.
 
Being in the states, that's what I prefer. I'd check with your local automotive parts guy and see what he suggests for CLEANING the system, not just a fuel stabilizer. If you ran 500 miles since, the gas shouldn't be stale but you could still have some build up in the system/injectors.

If you don't want to mess with the small front panels to lift the tank, you can remove the 2 front tank bolts and the one larger at the rear (by the front of the seat) and slide the gas tank back some. If doing this, I'd get the tank as empty as possible to make it easier to maneauver... The vent line(s) should be towards the top of the INSIDE of the tank. You want to make sure their not kinked causing a vacuum in the tank (basically running out of gas with a full tank). A non vented tank will cause all kinds of problems...
 
Well I poured in a recommended fuel cleaning additive and then went for a 70 mile ride - at first I thought it was my imagination but it felt like the bike got smoother the further I went. Maybe that's just me being overly optimistic about how quickly I would notice a difference with the additive in the tank. Anyway, I pulled back in to my garage and the over revving demon was back and she was idling at 2400 and then when I restarted her.. back to my normal 1400. :( Maybe it will improve if I give the additive longer to prove itself.

I'll take the tank off the way you suggested and hopefully that suggestion of yours will make the removal easier. Will report back once I've had chance to get under the tank! Cheers
 
Well the redex seems to have done the trick for now - I've also adjusted the idle down some and it seems to be behaving better. I will still get my dealer to put the new tps in if it hasn't been done already as the bike was due a recall afterall. Thanks for the help!
 
Just looking up throttle cable problems and this post came up. I'm sure you've found a solution to the problem by now but I had a similar problem with my FZ6. I've only had the bike running for a week and took it out for an hours ride – giving it a bit of a canning on the last stretch home.

When I stopped at a roundabout, the bike just cut out, I started it up fine but noticed that when it was idling it was stalling and the revs were well below 900. Got the bike home and let it cool down – started it up and all was good again - revs at 1800 at cold.

So on the advise of this thread, I bought some Wynns Injection Cleaner and whacked it in the fuel tank thinking a good clean would sort it out. Went out for a ride the next day and all was good for 45 minutes until I got to a roundabout and bingo - she stalled when at standstill (yes I did have the clutch lever pulled in). Handily there was a Maccy D's drive through I was able to park up at to have an inspection of the bike. Just as I was about to adjust the idle speed screw I noticed the throttle cable was frayed BIG TIME - only a couple of strands were left holding it together. I've just got back – having been rescued by Carole Nash breakdown and I'm now searching for a new throttle cable - probably get one on ebay from a breakers.

So fingers crossed, this is what my problem was – not dirty fuel injectors! if anyone has this problem – check ya Throttle Cable – at both ends!
Cheers
FZ6Rich
 
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