Questions on running 60:1 premix?

[rwhitlock]

I have a 97 CR 500 that I play ride on. Lots of trails, some smaller hills, etc.. I don't motocross it, but a few times a year I will hill climb it.

I have noticed that there is a lot of black gooey stuff around the exhaust port, as well as the pipe/silencer joint. There is not much black goop that comes out the tailpipe. This just makes the bike a pain to clean, and keep looking nice.

I am wondering if by changing to a 60:1 ratio will the black goopy stuff go away? I am running 40:1 now.

The bike runs fine, and I understand I may need to re-jet since there will be more fuel (due to less oil) in the air - fuel mixture.

Whadda ya think? Is 60:1 too extreme? Will I burn up the top end?

Thanks for the advice.

Rod

 

[Senior KX Rider]

Originally posted by rwhitlock


I am wondering if by changing to a 60:1 ratio will the black goopy stuff go away? I am running 40:1 now.

Prolly not ;) The ratio is not the problem. I would work on the jetting and stay at 40:1

 

[Zerotact]

My bike started shooting goop after I leaned the carb out.

 

[atc3434`]

I would say jetting, and what oil you run may be the route of your troubles. I burn Amsoil 40 to 1 in my bike, and she's a tad on the rich side on the warmer days, and I have no spooge at all. Just my $.02, but it might be worth trying a few different ones.

 

[David Trustrum]

1. Well for a start try sealing those joints a little better.
2. Never compromise engine protection for ease of cleaning.
3. Don’t confuse oil mixture vs air to fuel mixture.

It IS too rich so the petrol/oil mix that doesn’t burn exits the cylinder. In that mixture the petrol disappears leaving burnt coloured oil reside. If the combustion was complete it would burn most of the oil no matter what ratio you run.

Oil ratio is not your problem & anyone who says so needs a slap in the face with a wet kipper.

Your task is to find out where it is rich, pilot, main or all of the above. Guess one is pilot.

Read a jetting article & fiddle some brass.

Having said that a 500 is ridden out of peak power most of the time so lots of un-burnt fuel is lost -so will be inevitable to an extent.

 

[magneto]

I run Golden Spectro Full Synthetic at 32:1 in my 96 CR5 and it doesn't put out very much "spooge".