Yamaha Thundercat intermittent stalling

[Dannaz]

Hi All,

As per title, my bike came off its stand outside the house (we won't go into that, kicked myself enough) and damaged the left rearset bending it inwards towards the swing arm, so the gear linkage is slightly off and the clutch lever got slightly bent. While waiting on the parts to be delivered I have noticed intermittent stalling when sat in first gear, just seems to idle for short time and then dies off. Any suggestions what this could be and if possibly at all related.

I do have the parts now just need the weekend to come to fit them. Bike runs fine, idles fine and changes gear fine, just having these intermittent moments.

Any advice welcome

Many thanks in advance.

[podman]

I would have thought it would be unrelated with the only possibly exception being perhaps due to the fall some crap/debris came loose in the tank and has now made its way down to the carbs..

I'd wager 90% the cause of your problem will be the carbs anyway, when was they last balanced/given some TLC?

[Dannaz]

Cheers podman, I will look into this, they were prob done 10K miles or so, so prob due a check and clean. I have been getting quotes for major service including carbs, so it's been on the cards before the fall.

[evo8]

My VX800 cut out a few times on me and it was a corroded connection on my side stand switch, if your bike has one and it has been on its side, is it possible that it has been damaged/bent/etc and thus telling the bike the side stand is down and killing the engine?

Edited to add:

Edited by evo8 on Thursday 26th February 17:45

[Dannaz]

That's a good shout, it has a side-stand switch and did go over on that side, strange though as it's intermittent and not a complete cut off when it happens. The rev's dip and then it slowly dies off, as in starved of air and fuel etc.

But as I am changing the damaged parts I will check this out.

Cheers for input.

[Pothole]

evo8 said:

My VX800 cut out a few times on me and it was a corroded connection on my side stand switch, if your bike has one and it has been on its side, is it possible that it has been damaged/bent/etc and thus telling the bike the side stand is down and killing the engine?

Edited to add:

Edited by evo8 on Thursday 26th February 17:45

Exactly my first thought. I suspect the vibes and perhaps some specific pressure from the gear lever/linkage/etc. is making it gradually activate the switch.

[Dannaz]

Sounds about right from what you and Evo8 have said, as changing gear is more clunky now due to wear the peg sits to wear the gear lever is and the side-stand and switch are more exposed, so I'm guessing it's when I apply to much pressure, maybe worth replacing this as well then as could also have taken impact damage.

Much appreciated.

[Freakuk]

Clutch isn't dragging slightly when stationary is it? Does it happen when in neutral or in gear with the clutch lever pulled in? If you've bent the lever it could be that...

[Dannaz]

It's happening only when in gear and clutch pulled in, in neutral bikes absolutely fine and idles fine. When it does it, I can feel the bike trying to pull as though it's on bite point, although clutch lever is all the way in. I have noticed the lever is really slack and moves about since dropping it, also where the cable runs into the lever housing it now has play.

I have a new lever so will fit this and hopefully be able to adjust it.

[Freakuk]

Dannaz said:

It's happening only when in gear and clutch pulled in, in neutral bikes absolutely fine and idles fine. When it does it, I can feel the bike trying to pull as though it's on bite point, although clutch lever is all the way in. I have noticed the lever is really slack and moves about since dropping it, also where the cable runs into the lever housing it now has play.

I have a new lever so will fit this and hopefully be able to adjust it.

BINGO!!

Sounds like that's your issue, the clutch is dragging and having the clutch lever pulled in (now bent) isn't disengaging fully and causing the stall.

[Dannaz]

Cheers for the input, as I am not the most technically gifted person, do you reckon the new lever and correct adjustment will sort this? or will I also have to adjust it at the clutch on the engine as well?

once again thanks for the input, been doing my head in, as when it happens its been a case of Starter button/high revs/clutch release and go in one swift move.

[Freakuk]

Dannaz said:

Cheers for the input, as I am not the most technically gifted person, do you reckon the new lever and correct adjustment will sort this? or will I also have to adjust it at the clutch on the engine as well?

once again thanks for the input, been doing my head in, as when it happens its been a case of Starter button/high revs/clutch release and go in one swift move.

Really hard to tell, if there's slack in the cable as it is you should be able to adjust the play hopefully which should stop your issue, however if you've already got a new lever I'd change it and then see if that fixes the issue, if there's still slack in the cable you might have to adjust the play anyway.

I doubt it's anything else, certainly not the clutch itself, I don't know Thundercat engines, but assume the clutch is on the right hand side, if it's anything like an R1 I once owned they'll also be adjustment at the clutch end if required.

[Dannaz]

Yeah, I bought the clutch lever to replace it as it's bent back on itself. So this will be getting done first, and then I will adjust from there see how I get on. It always had a little bit of play as the MOT tester picked up on this, but it was comfortable for me, but now it's just excessive.

I will update the thread when I have made the changes.

Thanks to all that have contributed