Fuel Mix MX250A/MX360A

[Tossa]

Hi guys, I've got a MX250A and MX360A, have been having problems with fouled plugs, changed from natural based to synthetic, still ran at 25:1.  Big probs with plugs.  Noticed on another thread that they recommend 30:1 plus autolube.  This was from a set of specifications given Latest VMX had good article on oil choices suggesting 40:1 on synthetic

Am running standard jetting 260 main jet on 250 and 270 on the 360.  Don't want to fiddle with the jetting.  Anybody give me an idea as to what they are running

Barry

[cyclegod]

I run 20:1, using Castrol R30, in my MX250 and I used the same plug for 4 meetings without fail.

[Tossa]

I run 20:1, using Castrol R30, in my MX250 and I used the same plug for 4 meetings without fail.

You using standard jetting, and where were you on sunday!!lol

[cyclegod]

Standard jetting all round, and I was standing outside my house waiting to get picked up by my mate Marc so we could be flaggies but he was crook and didn't let me know until it was too late to get down in time (not that I could afford to drive that far by myself anyway).

[vandy010]

when it fouls the plug, is it by any chance when the revs drop back onto the idle circiut?
if so, i had the same problem with my 125 and traced it back to the pilot being too rich.
most of the earlier Yammies were too rich on the pilot anyway.

[Tossa]

when it fouls the plug, is it by any chance when the revs drop back onto the idle circiut?
if so, i had the same problem with my 125 and traced it back to the pilot being too rich.
most of the earlier Yammies were too rich on the pilot anyway.

No what you're talking about,but no not that problem, cheers

[JohnnyO]

Try running synthetic at 40:1 like they recommend, modern oils are not meant to be run at 25:1.

[LWC82PE]

have a good read here

http://ozvmx.com/community/index.php?topic=2533.0

[JohnnyO]

Why not read the article in the latest VMX mag about 2 stroke oils from Sean Phillips of Belray Australia. I think he might know what he's talking about.

[Tossa]

have a good read here

I read the link and understand it.

So what are people running in there MX250 and did they have to change the jetting


The problem I have in my head is that if I go to synthetic and the quote 40:1 is what everyone says.  but I am told I will need to change my jetting, I am also aware that some synthetics are better than others.   I realised that I have made a mistake running synthetic at 25:1, though it appears about correct for mineral based oils..  Think i'll start with the good old Catrol R at 25:1 and see where we go, or should i say if we go

[Tossa]

This was from a set of specifications given Latest VMX had good article on oil choices suggesting 40:1 on synthetic

Yeah read that thread

[LWC82PE]

Just because its in VMX mag doesnt mean its right. Remember Belray were one of the main instigators and pushers of 50 to 1  and lean ratios back then

[Tossa]

Just because its in VMX mag doesnt mean its right. Remember Belray were one of the main instigators and pushers of 50 to 1  and lean ratios back then

good point, should I also change plugs as using B9ES at moment

[vandy010]

my manual states B8EV for the MX250a {mine is using a B8ES},
i use shell advance sx 2 stroke oil at around 23:1 with no probs.
but then again, my MX250 only has about 10~15 minutes of ride time on it since its rebuild so i'm still yet to fully see how it runs. CD6 will be my test for that bike.

[JohnnyO]

Just because its in VMX mag doesnt mean its right. Remember Belray were one of the main instigators and pushers of 50 to 1  and lean ratios back then

Are you saying the rep from a major oil company doesn't know what he's talking about??
Ha..I've heard it all now