Yamaha TRX850 Enthusiasts Forum

I HAVE SPLIT THIS OUT OF THE STARTING PROBLEM THREAD AS YOUR PROBLEM IS POTENTIALLY VERY SERIOUS - PHUK72


Hi all,could someone tell me what the life of a starter motor is?,i bought a 97 plate trx a couple of months ago,i have been riding it but didn`t for the last two weeks,went to start her last wednesday and there was an allmighty knock from the front of the engine and no start,my neigbour seems to think that it could be the starter motor on the way out.Anyway we tried bumbing her but didn`t have any success,then as i pushed her into the garage which is on an incline tried and she started!,i rode her for 4 miles but she didnt want to tick over as normal,meaning allmost like she needed constant choke.i have also noticed now that the oil level seems higher than normal and very runny?.would be gratefull of any help given.

swimm68 wrote:Hi all,could someone tell me what the life of a starter motor is?,i bought a 97 plate trx a couple of months ago,i have been riding it but didn`t for the last two weeks,went to start her last wednesday and there was an allmighty knock from the front of the engine and no start,my neigbour seems to think that it could be the starter motor on the way out.Anyway we tried bumbing her but didn`t have any success,then as i pushed her into the garage which is on an incline tried and she started!,i rode her for 4 miles but she didnt want to tick over as normal,meaning allmost like she needed constant choke.i have also noticed now that the oil level seems higher than normal and very runny?.would be gratefull of any help given.

Just hang about, someone will be along in a little while.
I have limited knowledge of things that go knock in the night.......... but .....runny oil?...... does not sound like a starter motor.
Sorry,really not helping!

WARNING WARNING... DO NOT RUN YOUR BIKE UNTIL YOU CHANGE YOUR OIL. My guess is that you have a fuel leak from either your carb's, fuel tap or fuel pump. This let's fuel past the piston's and into the crankcase, diluting the oil and it could cause havoc in there. Check your vacum line's are connected to the correct spiggot's first.

Yeah, that big bump was probably your l/h big end bearing giving way, check it out before you go any further.

Oh, welcome to the forum BTW!

Check your oil.

Starter motors start - nothing else. And they don't go clunk when the bike is running.

Fingers crossed it isn't your big end that has gone.

I have PM'd you to explain why I have split this out from the other thread and suggested you come back and ask more questions!

check if the fuel tap is horizontal...if it is then you probably have an engine full of fuel....the tap has a vacume line from the manifold to open the fuel to the carbs only when the engine is running...if this is not working [ for many reasons ] then people dangerously resort to use the open /prime setting //horizontal setting on the tap so to find fuel flow....then the fuel might pressure past the carb needles/seat while the motor is resting, and fill the cylinders ,,maybe a backfire is the bang that you heard....if so..so sad...

Thanks all for the response, you know I had a work related call on today and thought at 8am, i going to see if she starts again and ride her to the job instead of the van, well she fired up no problem inside the garage (doors open!), then I noticed that there was steam or smoke or whatever you want to call it coming from the bit of the pipes where the cans are connected. There were also black marks where it looked like the cans were originally fixed; somehow they have slipped back about an inch? So I loosened them off and fixed them back correctly, started again and perfect ticking over this time. Because I am a complete novice with bike mechanics I thought that I would see how hot the engine has to be before the cooling fan cuts in, after about 15 minutes and a temperature of 100 it did, and dropped pretty quick too. I rode her to the job about 20 miles away and back with no problems whatsoever. The oil will be changed this weekend and hopefully all will be well.I am really happy with the trx,my neighbour has a zxr1200 and has a job to catch me on the twisties,they really are quite throwable these twins,if there is anyone out there that has a set of nice sounding cans for sale i would be interested,cheers all.

The good news is that if you have ridden the bike and there is no knocking noise, then maybe you haven't fecked the motor ...... yet!

Still doesn't solve the issue of the bang (although this could be popping cuased by air leaks on exhaust) or the runny oil. You do know how to check the oil on a dry sump engine like a TRX? Sorry if this sounds stupid but a lot of people dont.

A search on here will reveal the answer.

If you have any problems, post on here and we will set you right.

Oh yeah - and the TRX has 2 oil drain bolts

Get that `runny` oil out of it IMMEDIATELY, do not run it again until you do.
If it were me I would go to the nearest Asda or Tesco`s, buy cheap oil, run it till warm on that then drain the lot out and refill with a good semi synthetic 10 W 40, I use Halfords own brand.
If that `runny` oil that comes out smells at all of petrol get the fuel tap and vaccum pump checked out, as others have said they can flood the motor wth fuel when standing if the diaphragms in them fail.

Also buy a lottery ticket (or what ever they call them over there,).

amazing how a loose exhaust flange at the can will fix an engine knock , highly viscous oil and a strong odour of fuel.. ..youve had a big explosion inside the headers to push the end cans back an inch or so which would have come from the cylinders clearing leaked carb fuel into the exhaust system...you still have runny oil and a fuel tap problem...the oil may have become thicker with the hot engine but if you or anyone leaves the fuel tap at the horizontal [prime ] position while the bike is [resting]..you are asking for expensive trouble...

+1 with Alex, do a search, you won't be the first to murder a motor by having a leaky fuel tap!

As Mince said, get that oil changed immediatley. oil levels go down, not up!

Dave E

With the petrol/ oil mix thing is there a risk of a seriously big explosion from the crank case?

I had a similar thing in an old Ford Cargo Truck, very different engine, but similar problem, fuel going into the engine, It didnt expolode as such but started "Deiseling" as someone refered to it baisicly firing inside the crank case using the fuel and oil mix as fuel. I could not stop the engine by any normal means and had to stall it, I nearly burnt out the clutch doing so, with the revs being so high and on full power the brakes could hardly stop it, it stank for quite a while (as im sure did my pants! )

Anyway with the petrol being much more flamable than deisel and the temps in the engine being high= bang???

I wouldnt want to risk it anyway!

Change oil

Fix fuel

BE SAFE!! (you only get one pair!)