Shift probs after oil change

[bekker]

Can anyone shed any light on this problem?

I have a 79 Suzuki GS550e and recently changed the oil from 10w40 to 15w50. I did this because it was burning a bit of oil and has high mileage and is generally a bit on the worn side. I had been running Silkoline 10w40 but this time went for Castrol Activ 4T 15w50.

Since the oil change (and I'm pretty certain this isn't just in my head) the gear change has become harsh and it's now difficult to select nuetral.

Now with my limited knowledge I had assumed that the change would if anything have become easier using the slightly heavier grade, not the other way around.

Did I mess up? Everything I've read indicates that this oil is suitable for wet clutches but could I be wrong or would that only effect the clutch operation (which is still fine) and not the gearbox.

Cheers for any help.

[CookMySock]

changed the oil from 10w40 to 15w50.No, you can't do that. :nono:

Steve

[MSTRS]

It won't be affecting the gearbox. The new oil is slightly thicker, so may be causing a little drag in the clutch, which will make selecting neutral difficult. Try adjusting your clutch cable/lever to allow a greater degree of pressure on the disengage mechanism. Just make sure that the lever on the crankcase still has a slight freeplay.

[vifferman]

I'm not familiar with either of those oils - are they mineral, semi-synthetic, or full synthetic?
I found that with my bike, the 15W-50 gave better, smoother shifting than 10W-40, and (despite everyone raving about it), the full synthetic was worse than either.

[The Pastor]

Edit:i dunno what im on about

[bekker]

I'm not familiar with either of those oils - are they mineral, semi-synthetic, or full synthetic?
I found that with my bike, the 15W-50 gave better, smoother shifting than 10W-40, and (despite everyone raving about it), the full synthetic was worse than either.

Both mineral I believe, although the Castrol website is rubbish - on one page it says it has a synthetic base, on the other it says mineral!

I run synthetic in my car, but can't really justify it on an old bike that burns and leaks oil and needs changing so often.

[rossrc]

I've come across something similar with a DR650 based bike and I found a thread where lots of people were getting clunky changes with certain types of oil. Most of them were yanks, so changed to an oil I've never heard of. My bike was ok when I was running basic Castrol GP (don't know what it's called now), then I gave it some of the good stuff i.e. fully synth and the g/b felt like crap... next oil change I'll go back to the cheap stuff
BTW as DangerousBastard said, I don't going from 10w? to 15w? is such a great idea, espesh in winter - everyone says most of the wear happens when the engine is cold... just my 2 cents

[LBD]

Both mineral I believe, although the Castrol website is rubbish - on one page it says it has a synthetic base, on the other it says mineral!

I run synthetic in my car, but can't really justify it on an old bike that burns and leaks oil and needs changing so often.

Wait till you come accross ISOSYN oils....

First couple posts are correct, the 15W causes the clutch to drag and makes shifting difficult.

With regards to smoking or burning oil, a common mistake often made is to use a heavier oil and without realizing it, use an oil also suitable for some diesels. This has a higher detergent level and will clean out gum and combustion residue from rings causing a loss of oil control...more oil being burnt.

Motor bike specific, correct Viscosity and in particular wet clutch compatable oils are important.