Yamaha TRX850 Enthusiasts Forum

Hi guys -

I have done about 800 miles on my TRX and have had to fill the oil from min to max two times.

I am not sure how much min to max is - i would have said not very much, but perhaps 250ml something like that?

I always check and fill from cold.


Is this acceptable oil consumption, and additionally when i change the oil what grade should i put in?

I suppose it depends how you'd define 'acceptable'. Mine will take about a litre in about 1000 miles. I can live with checking the oil (warmed up and just after I stop the engine) as the bike is such good fun to ride. It's a case of just putting up and shutting up until I can get a big bore done on it

Yamaha regard 1 litre per 1000 miles as acceptable / normal

since my engine rebuild , 878cc kit and valve stem seals plus a big clean up of all the engine internals,, i have now done 650 miles,, mine uses NON so far , and i honestly think it was more to do with stem seals than anything else , i am still on a Mobil 15/40 mineral oil yet and it will be until 1000 miles then i will put mine on silkolene 10/40 race as its one of the few true synthetics ,, if you do decide to go for stem seals go for Yamaha bits as the pattern ones are not right , (i have some pattern ones here you can have ),,, if your having to keep topping the oil up my advice would be to use a cheap semi synthetic and always take a liter with you under the seat , keep a close eye on it as low oil will kill your engine , there is only one way to stop the consumption and that's to strip it down and fix it ,, rings and stem seals and then run it in hard as per,,,, http://mototuneusa.com ,,,,,instructions ,, good luck

Steve - like you my bike uses no oil at all. But I'm curious about you using fully synth oil. Mine hated it - it sounded awful and the clutch slipped.

So for ages I've been using any semi synth I can lay my hands on (currently using Hein Gericke white label oil at less than £13 for 4 litres) - that said, it does get changed every couple of track days or after about 1500 - 2000 miles (usually with my tyres).

when you used it what grade did you use ? if its 5w/30 that would explain it but the 10w/40 i have in mind should be the same as any 10w/40 and the sikolene is a proper synthetic oil ,,,not like castrol which is not,, to be honest the 15w/40 mineral mobil oil i have in now is great ,, the gearbox is fine as is the clutch , its just that i know that synthetic is a better oil and silkolene 10w/40 race is one of the best

steve speed wrote:when you used it what grade did you use ? if its 5w/30 that would explain it but the 10w/40 i have in mind should be the same as any 10w/40 and the sikolene is a proper synthetic oil ,,,not like castrol which is not,, to be honest the 15w/40 mineral mobil oil i have in now is great ,, the gearbox is fine as is the clutch , its just that i know that synthetic is a better oil and silkolene 10w/40 race is one of the best

I did try race oil but it also did it with 10/40. Used Fuchs (which is same as Silkolene) and Motul - both the same result.

What oil do Yamaha recommend, semi-synth or fully? Not that I'm that chewed- I put some generic diesel oil in mine at the last change and it's fine. I thought the TRX lump was too agricultural to be that fussy about a fully synthetic 'race' oil.

Kayla wrote:What oil do Yamaha recommend, semi-synth or fully? Not that I'm that chewed- I put some generic diesel oil in mine at the last change and it's fine. I thought the TRX lump was too agricultural to be that fussy about a fully synthetic 'race' oil.

Pretty sure Yamaha recommend any 10/40 - don't thnk they specify smei or fully synth?

As I said, i now use HG cheap semi synth oil and change it a lot

Ah, speaking about oil, I just read this in the Haynes manual (aka the great book of lies):

Oil type: API grade SE, SF or SG
Oil viscosity: SAE 10W30 or 10W40

Caution: Yamaha advies against using chemical oil additives, or oils with a grade of SH/CD or higher, or oils labelled ENERGY CONSERVING II. Such additives or oils could cause clutch slip.

after spending a small fortune on Castrol power RS (10W40) with API grade SJ.
So that would be too good in quality! I just put the oil in, because I don't think the cluth will slip.
But will "thin" oil with a low (or is it high...) level of viscosity result in higher oil consumption?

if you put 20w/50 in it might use a bit less , and its a big might as at running temp it should be a bit thicker but it WILL still get dragged down the stem seals and sucked past the piston if the engine is not in good nick and if its not it will dilute your oil due to blow by gas ,, also there is a problem if you live in a cold country like the UK as the oil wont get round the engine so quick when its cold ( which is most of the time ) any 10w 40 oil will be OK if you change it every 2000 miles , i just like using the good stuff in my pride and joy but i did pick up some silkolene 10w40 race today for £24 so that's a good do ,,,and to kayla ,,,, Yamaha recommended 10/40 over ten years ago , things have moved on a LOT since then

Stem seals would make sense to me about oil usage.

I will see what is in it now, oil wise - i think i am using 10w40, as i say the consumption seems to be about 700mls per 1000 miles, which is certainly not a major problem, more an annoyance!

I always check my oil after running my bike for at least 15mins.

I use Nulon 15W-40 SL rated diesel oil and do not need to top up between changes (3,000klms)/

I originally used Motul , and since the change to diesel oil I have found the gearbox to perform much better.

My bike is a 2001 model and has now travelled 31,000 klms.

I agree that you could have valve stem seal issues, or your motor could just be worn.

I have owned Trixie for 2 years and always follow the same ritual when I check the oil level.

It's critical as I have seen the results of neglecting to check oil level correctly.

Troublemaker, check your oil level when the engine has been run for about 15 plus minutes, that will get you a true level, I use castrol semi synth, due to temperature here, racing I would use a thicker oil, The engine itself is quite solid and will take different oils, tolerances are not so great as say the latest R1, and again it doesn't rev so hard and high.

Dave E

steve speed wrote:if you put 20w/50 in it might use a bit less , and its a big might as at running temp it should be a bit thicker but it WILL still get dragged down the stem seals and sucked past the piston if the engine is not in good nick and if its not it will dilute your oil due to blow by gas ,, also there is a problem if you live in a cold country like the UK as the oil wont get round the engine so quick when its cold ( which is most of the time ) any 10w 40 oil will be OK if you change it every 2000 miles , i just like using the good stuff in my pride and joy but i did pick up some silkolene 10w40 race today for £24 so that's a good do ,,,and to kayla ,,,, Yamaha recommended 10/40 over ten years ago , things have moved on a LOT since then

I've been using 20w-50 in all three of my twin cylinder machines for some time now (TRX, TDM & V-Strom 1000) never had any issues with cold starting or oil pressure problems, even after a winter layup in northern germany.

Silkolene 20w-50, semi synthetic.

mike