Yamaha TRX850 Enthusiasts Forum

Well was running fine, no problems, pulls hard, everything works well. I try and starting it and it just wont fire up, will crank, but nothing. There is fuel, and there is spark, but nothing, i dont get it. any wise information ?

is it cranking normally? or is it cranking a little slow? i've had cases where the bike will crank but not start... try and jump start it though and it starts first go... i assume this is down to the fact that the battery is on it's last legs, and has enough grunt to crank the engine over, but not fire up the spark plugs as well... dunno if this is acctually what's happening, but it fits the description...

other then that i'd just be covering the fundamentals... engine needs 3 things to run... air, fuel and spark... check that all 3 are doing what they're suppose to be doing.

jake wrote:Well was running fine, no problems, pulls hard, everything works well. I try and starting it and it just wont fire up, will crank, but nothing. There is fuel, and there is spark, but nothing, i dont get it. any wise information ?

Need to give a bit more info there mate.

Where have you got fuel to?

whats the compression ratio like, how many ks are on it. ??? could the rings have let go????

TRiXy wrote:
other then that i'd just be covering the fundamentals... engine needs 3 things to run... air, fuel and spark... check that all 3 are doing what they're suppose to be doing.

you need compression as well but that's just me being pedantic

Try bumping it or get it hooked up to another battery or jump leads and see if will start / run.

i had same thing a few weeks back and it was just oiled plugs (and possibly 3 month old fuel).

G'day Jake.
I would be banking on the battery being low like TRixy said.I have had the same senario.Put the battery on charge and I reckon you will be sweet.
Terry

Well, the battery is good, ive charged it and its fine. The rings are new, ive rebuild the engine. I think ill take the plugs out and give them a bit of a clean and inspection.

jake wrote:, ive rebuild the engine. .

You´ve had it started after the rebuild have you!?

Is the fuel okay? Its not unknown to get contaminated fuel sometimes if the petrol station tanks are nearly empty. There is sometimes water in the bottom of their tanks. Worst case I saw was an e type jag a friend had. Filled up at one station, car ran for a few k's then stopped dead. Called the AA who had to drain the carbs and lines and syphon a bucket full of water out of the tank.
Put in some methylated spirits to mix with any remaining water, fresh fuel and da da running sweetly again!

valve timing?
vacuum hose off?
bad fuel?
plug leads swapped?
so many things.

Yes after the rebuild the engine was running well, pulled really well (mmmmm), anyway, the plugs look good, i check them and a spark is coming out. Fuel is getting to the carbie because i unplug the main fuel line that goes to the carbie crank the engine and plenty of fuel coming out. Ive got no idea what it could be.

Did it tick over ok?, could be the usual tubes, try putting new plugs in and firing it up.

Dave E

Have you tried starting with the throttle wide open? Might help.

Ok well, its still not starting, heres the check list

1. Ive got spark
2. Fuel is good because i tried a different one
3. Its got Air
4. Batter is good ive charged it

It will crank, and keep on cranking, but nothing, sometimes it will blow out the exhaust a little bit and thats it.

Its got me puzzled.

Any more ideas ?