Yamaha TRX850 Enthusiasts Forum

Wise council needed please

I've always known my bike was a drinker, but as I only ride for pleasure once a week I haven't worried too much.
But now I am booked to go on a gentle tour of northern Spain in June ( 100miles a day for 10 days) so I've measured the consumption.

turns out its used 700ml in 324 miles.

which I think equals 1l in 463 miles? as I think I've read the upper limit is 621miles per litre to be within norms I have to decide whether to strip down and shell out for rings, honing and valve guides or not.

If I do, there is the expense plus the possibility that my iffy spanner work will cause other things to go wrong that are working fine atm.

If I don't I'll be topping up the oil every day and having to devote precious luggage space to 2 or 3l of oil ( and looking a bit foolish)

I've read here that changing to mineral oil (I'm on fuchs semi-synth) can reduce the thirst, would that mean using a flushing oil ( whatever the procedure for that is?) .

Does anyone have any advice please?

thanks

mike

Go for the cheapest option and take 4litres with you.. and just enjoy your holiday and top up each day..
I'm sure you will be up for at least 100 pounds just for rings,head, base and cam cover gaskets.
Guides shouldn't b an issue but personally I would replace the valve seals while the heads off and you may get away with the cam chain but if over 40,000km's I would think twice..

Unlike back in the old days when you ran things in progressively. things have changed in engineering of motorparts and the honing and bedding of rings has changed too.
The honing in barrells is not as course as it used to be so the first 20minutes is critical to getting the rings bedded so plenty of load it get it all to bite in and bed to stop glazing.

Buy some oil, enjoy your holiday then think about the motor...

Thanks Cobba. It goes against the grain a bit to do nothing until I get back but I think you are making a lot of sense there.

Don't stress. Touring on a worn TRX just meas adding some oil at every fuel stop to keep levels correct.
You'll become an expert sight glass calculator

thanks for your comments guys, very helpful

Now then. I had the same ploblem last year and I got some good information from this site. If you can find my posting Honing Tool then you may pick up some usefull starting points. I bought a flexhone, rings, two gaskets, valve seals and shimms.I'll try dig out the costs and supliers this weekend.

Hi Mike
Like the others have said before, just put the oil in and enjoy the holiday. I did 4000 miles in one trip abroard and had a complete oil change plus a bit more. The trip will confirm weather this is the bike for you, if it is then you'll want to cure the problem. If not, then no doubt you'll put it on ebay when you get back to UK.
Here's a couple of items you may require for fix
AJSutton.co.uk - Piston ring set £26.03 each
AJSutton.co.uk - valve stem seals £1.80 each
Wemoto.com - Head gasket £35.59 (didn't bother with the base and made cam chain tensioner gasket out of cereal box)
Wemoto.com - Exhaust Gasket £1.27 each
Hot Cams - Shims if required £2.60 each
Honing Tool. I bought a Flex-Hone direct from the US at £37. You can go cheaper from the likes of Cromwell, Northern Tool, Screw Fix??

Don't forget it only takes a day or evening to strip a bike, putting it back to gether is another story. Thats how we end up with more than one motorcycle or so I keep telling her. You don't want to be working on it the night before the Ferry, I did and lost a gear change .

Cheers Albertorondm

Hey Alberto many thanks for posting and digging out the info for me. Thats really helpful to know and I will be using the knowledge when I get back. I already know the bike is a keeper as I sold my other bike which was a low mileage rf900 suzuki ( I do miss the outright acceleration, but the trx has soul)

I have already started trawling the site and will be doing a major re-con over the winter.

is the consensus cause for oil consumption the bores? My thought was valve stem seal, based in there being black resedue at the bottom of the intake manifold.

Planning to replace all the intake valves (96 model) and replace the 10 valve stem seals. Most likely I will swap the cam chain for a new one while I am at it

Con Rod wrote:is the consensus cause for oil consumption the bores? My thought was valve stem seal, based in there being black resedue at the bottom of the intake manifold.

Planning to replace all the intake valves (96 model) and replace the 10 valve stem seals. Most likely I will swap the cam chain for a new one while I am at it

You are on the money Con Rod. When I did the rings, inlet valves & stem seals on mine at about 75,000km the bores were pristine. Make sure you get the 97 & later inlet valves. Now at 140,000km compression still good, no trouble with valve clearances but it does like to drink oil again....

good stuff. I've order parts to do the cam chain, rings, replace the inlet valves and all valve stem seals so will be doing it in the next few weeks

it's not the valve head or stem that is the issue on the earlier TRX's it's the valve seats suffering valve seat recession .
Here is some info on the this very subject.
You will find the later models have a harder seat..
http://www.go-lpg.co.uk/VSR.html

$300 to ceramic coat the valve stems and heads, combustion chambers ,exhaust ports, piston crowns and sides so keeping the temp down here has so many benefits , not only in how the fuel burns but added protection benefits too.
Well worth it in my eyes..

We covered this a while back. For those that missed it...

http://www.trx850.com/phpBB_forum/viewt ... =36&t=9638


Mark.

I can see now the difference in part numbers from 96 to 97 being revised on the 2 inlet valves .
the final 2 numbers being -00 for 96 and the revised with -01 for 97 and onwards and continuing with the same revised number on the TDM 900 models.
I stand corrected..
So the 95-96 model valve head is the problem causing all the dramas..and this in itself can ultimately cause damage to the seat.
Is this correct Mark??

I will take some pictures of the head when I do mine