Yamaha TRX850 Enthusiasts Forum

I had a weird event today. Just after getting on the bike and waiting to leave the carpark at work the bike stop while at idle. Cool, no worries just hit the start button. Hmmm....... won't fire. I went through all the checks, fuel, leads, fuses etc. Still turned over fine but wouldn't fire. I then started messing around with the gear shifter. I put it into gear and back to neutral a couple of times and it fired up. I sat for a while and then headed for Mt. Cootha for a quick blat before going home. After the Mt. on the highway bike cut out again. I pulled over and tried starting it again. Had a fiddle with the gear shift and it fired after a few jiggles and gear changes. Now I know there is a kick stand switch but is there also a switch in the gear box itself that maybe faulty. I would have thought it would prevent it turning over like when you have the kick stand down. Is this a common problem at all. I can't see it mentioned in any of the forum searches I did. Besides that loving my new bike. Still pretty a fairly cautious rider and am no where near it's limits. Waiting for a track day with some tuition to learn about that.

The only 'kill switch' I think is on the sidestand. Think this cuts the engine WHEN YOU PUT IT IN GEAR if the stand is still down.

They can get general road crap and water in them because of where they are and stop working/short.

If yours did this shorting, the bike would think the stand is down when it's not, and cut out when you put it in gear, maybe just intermittently.

I'd discunnect the wires from behind the sidestand mount, and just give it all a good clean, including the switch, make sure your connections are tight, give it a spray with a protector, and see if it cures the problem.

Dave.

PS that quote on your posts "racing is life.." has been bugging me to remember who said it: was it Steve McQueen, or Barry Sheene maybe?

Don't have the manual here, but logically, there has to be some kind of gear-indicator as well, how would the bike know to kill the engine when sidestand is out, but only when not in neutral? On the other hand, the indicator should not alone kill the engine, but has to work together with the sidestand switch? I'd check the side-stand switch first, if You short-cut it and problem goes away, then You know what's wrong...

It uses the neutral switch, this is the only 'gear indicator'. If the neutral light is working then there's a good bet that the problem is not with the neutral switch.

It also uses the sidestand switch, and the clutch switch.

if it is in neutral it should turn over regardless of the state of the other switches.

A combination of the gearbox not in neutral and the sidestand being down will also kill the engine (with the clutch lever not pulled in)

If it is not starting but it's turning over then it's not likely to be any of these three switches.


In my experience, if it turns over but doesn't start it's normally due to incompetance with the choke. - probably not the cause here.

burty wrote:It uses the neutral switch, this is the only 'gear indicator'. If the neutral light is working then there's a good bet that the problem is not with the neutral switch.

It also uses the sidestand switch, and the clutch switch.

if it is in neutral it should turn over regardless of the state of the other switches.

A combination of the gearbox not in neutral and the sidestand being down will also kill the engine (with the clutch lever not pulled in)

If it is not starting but it's turning over then it's not likely to be any of these three switches.


In my experience, if it turns over but doesn't start it's normally due to incompetance with the choke. - probably not the cause here.

is the correct answer

burty wrote:It uses the neutral switch, this is the only 'gear indicator'. If the neutral light is working then there's a good bet that the problem is not with the neutral switch.
...

Agree with all U say, but explain this (off-topic):
my neutral light is always on, but the side-stand and clutch switches works as they should. But when the engine isn't running, then the neutral light works as it should...

I hate electrics...

BTW, isn't that a difference compared to the TDMs, that they actually have a gear indicator instead of our neutral-only indicator. Had something to do with emission and sound control, and there was an extra wire going to the CDI-box?

HansJ wrote: Agree with all U say, but explain this (off-topic):
my neutral light is always on, but the side-stand and clutch switches works as they should. But when the engine isn't running, then the neutral light works as it should...

I hate electrics...

That is strange.

Possibly some adjustment/wear issue with the neutral switch perhaps, which causes it to be on when the engine is running? I'm guessing, as I know nothing of what activates the switch.

since removing the fairing off my bike and removing the unused wires from the loom my neutral light that i fitted lights up at half brightness every time i pull in the clutch then extinguishes when i let it back out. guess my customised wiring loom must be to blame even though i've not routed anything differently

trixynut - Steve McQueen

Thanks for the help so far guys.

Well, I am buggered now. The side stand/clutch/gear switch all seem to work as normal when I left for work this morning. Pulling up to some lights near home it starts to miss and then cuts out. I tired the whole gear change /clutch in out/side stand thing but no go. After a while with a little choke it did fire but was very rough and as soon as I cracked the throttle then it would cut out. In the end the battery wouldn't crank enough so I rolled it home. I have the battery out checking all the connections at the moment, fuses, solenoids etc. I don't know now. I have rebuilt car engines and done up cars but this is hard without the manual.

t-rex 850 wrote:this is hard without the manual.

You've got a pm t-rex

Hmmm........ looks like I am the village fool today. Seems I got a little mix up with the fuel tap and where I was at with the fuel in the tank. Should have check with a torch. I just heard the last of it sloshing around and thought there was enough in there. Still not sure if yesterdays first incident is related but time well tell. It was good fun pulling the bike apart to find the tank feeling a bit light. At least I had a chance to get a better look at where everything is under there. Thanks for all the quick responses with things to look at.

Good news Sean, that means you can come out and play on Sunday or Monday?

Glen1TRX wrote:Good news Sean, that means you can come out and play on Sunday or Monday?

For sure

May do. My wife is about to girth to our third so I can't really stray to far in case it all starts occurring. I will be working Monday as well, won't be a full day though. I will holler if I can get out but.