Motul 3100 or 4100?

[loubre]

Hi, any oil gurus out there to give me some advice please? Am currently running Motul 4100 10/40 in my 99 GPX250 but my local kwaka dealer has got the 3100 15/40 on special (15% off), average temp range here at present 14 to 28 degrees but will average 24 to 35 later during the wet, will it make much of a difference going with the slightly heavier oil, the little grasshopper has got just over 50000 k's on her and apart from the usual little rattles when cold still runs sweet! Not tyring to start an oil debate but any advice would be appreciated, thanks. Lou

DSC_0026 (640x428).jpg (241.03 KiB) Viewed 2557 times

[MAXUMIS]

with that many km's on her i would go a thicker style of oil depending of the style the bike has been riden but with thicker oil it MIGHT make it rattle more when cold as its harder to get into the timing chain tensioner(you might need a new timing chain)!

[loubre]

thanks, mainly used to get to and from work now a days with the occasional run down the track a bit, not too far that b seat does not make long runs much fun for my ageing bones now! cam chain was replaced at 40000 ks.

[dickfaber]

one of my gpx 250's had an engine that sounded like it was ready to fall out, and I always use motul 4100. was talked into using royal purple syn for bikes (and it was heavier too). caused the seals around the plugs in the rocker gasket to go (dunno why, and noone can tell me why). went back to 4100 and the leak stopped?

my thought is stay with what you (and your bike) know

[loubre]

Ok, stayed with the Motul 4100 but went with the 15/40, Repco had both 10/40 and 15/40 on special, no noticable increase in noise when cold but does seem a little quieter when warmed up, thanks for the advice, greatly appreciated.