Oil change

[Guest]

I'm going to put a new oil filter in my 1981 gs450t. But I'm wondering what is the best type of oil to put in this bike. I've heard a lot of people say some synthetic, others say non synthetic, some say diesel motor oil. Any particular brands to stay away from, like penzoil because it has some type of cleaning additives? I heard any additives were bad for a wet clutch? I feel like I should go with a basic non synthetic because it's an older engine, the bike says 10w40 but it's summer so I think I should account for the heat, if so, what should I go up to? 20w 50 maybe? Please tell me what you use in your Gs and all your suggestions.

[tkent02]

Most of us use Rotella, either the synthetic or the dino oil, your choice. It's fine at any temperature you might want to ride in. It's fine with the wet clutch. I put it in all my bikes, BMW, KTM, Suzukis too.

[John Park]

The GS400/450 six speed has a habit of false neutrals and often hard to find real neutral, plus a tendency to be stiff going into sixth. First thing is not to use anything other than motorcycle specific oil. You may get lucky and find a car oil that actually shifts nicely and doesn't make the clutch grabby, but that will take a lot of looking. And even if it does, it probably won't for long. It's not that you can't live with a cranky gearbox and a grabby, draggy clutch but why would you want to?

My oil of choice in a 400/450 is Motul 7100. I used to use Motul 5100 semi synthetic but it's been discontinued, although there's still some out there. One of the side benefits of Motul is that they seem to have got the formula right for keeping seals supple and even 'resupplicating' old seals. Their fork oil has the same properties. I'm not saying that it's the only oil that will perform like this, but it's been doing great for me in 400s for, well, I'm older now…..

I would caution against using budget oil even if it has a Yamalube' type brand on it. It's often no better than typical basic car oil. It won't ruin your engine. These motors will survive on some pretty basic lubes as far as not destroying themselves, but they just won't rev, shift or stay dry like they will with a good synthetic. Synthetics are also far more stable at high temperatures so they can be left in a lot longer than conventional. I said can be, not should be, as they will still be subject to things like fuel dilution and condensation and such, but on a long trip you'll be less guilty of going over the schedule.

If you haven't tried something like Motul 7100 yet, you deserve to treat yourself. It will rev more willingly and, especially after it works itself in, the drivetrain will be way nicer. On a 400 you have six gears, four main bearings and two counterbalancer bearings so there's similar drag to a four cylinder bike but with less power, so the difference is more dramatic than with the fours. More fun.

If you can't find Motul, Optima, Golden Spectro and Maxima are pretty similar. There is also no reason whatsoever to go to a different weight; 10w40 is what the internal passageways, pump, etc are designed to work on and the last thing you need in a high rpm engine is a thick and slow flowing oil. I've used 20-50 in the old roller crank 400 doing high speed running in Mexico and just found it made the motor sluggish.

Additives are unlikely to do much for you. You can't take a $4 oil and add some magic supplement and make it a $15 oil. People can believe the wackiest stuff about lubrication and there is no end of opinions but I'm quite happy to let the lube engineers do their thing. After all, what would they know?

Other than air cooling, there's nothing 'older' about these motors that would mitigate against using synthetic, and air cooling is a good argument for it. I've run the snot out of this motor as in 70-85 mph all day in the desert on synthetic and no problems. I'd be more wary of fuel quality which can be a real crapshoot.

[tkent02]

The GS400/450 six speed has a habit of false neutrals and often hard to find real neutral, plus a tendency to be stiff going into sixth. First thing is not to use anything other than motorcycle specific oil. You may get lucky and find a car oil that actually shifts nicely and doesn't make the clutch grabby, but that will take a lot of looking. And even if it does, it probably won't for long. It's not that you can't live with a cranky gearbox and a grabby, draggy clutch but why would you want to?

Or you could just go with Rotella. It works fine.

[Charlie G]

Use Rotella 15W-40.

[Brendan W]

This might help with an overview.

http://www.vfrworld.com/tex_vfr/tech/oil.htm

I use 10W40 semi synthetic. Have noticed slight differences in gear changes between brands. Experimenting with a 15W40 at the moment. With short change intervals I don't think synthetic is worth the extra expense.

[GSXR7ED]

Synthetic

Rotella for sure!

Ed