Spooge, Jetting, Mufflers, and Motul 800

[Mohave]

Wanted to get some ideas on why my bike has these "Spots O Spooge" (SOS) on the fender, myself (don't ask), the muffler, and anywhere around the back end of the bike.  2002 with fresh OEM piston/rings, well jetted, plenty of power, starts first kick hot/cold, etc.  One thing after riding with USMC500 I decided that I would cut off the tip off the FMF as I liked the look.  I then decided I really didn't like being "tipless" (no offense Oscar) but did not like the stock FMF "droop" so had a straight tip put on.  I don't think this is causing the "spots o spooge" but the exhaust is exiting straight out instead of down. 

Jetting is 168/stock 3rd clip/55 and I have tried lots of different combos.  Stock carb with stock reeds.  I have run the ratio from 40:1 to 80:1.  Less SOS at 80 but still there.  I run 10oz of TORCO octane boost with 91 octane CA gas for 5 gallons.  40:1 feels fat, 80:1 feels best.  I usually end up at 70:1.  Been in the motor a few times while experimenting with the bike and getting used to the 500.  No carbon, everything is nice and wet, looks great.  Plug is always black, maybe a little wet, and never fouls.   I always run my 500 a little rich here in the desert.  Have 45 hours of engine time.  Seems like it started 10-15 hours ago?  Do I just weld a 45 deg on the tip and not worry about it or is something up?  Is this normal?  No change in the power at all, bike has always run very well.

[Motorrad]

Oil your chain alot?    Looks like chain flickins to me

Warning. On my phone.  So pics are small


What oil ya running?

[2-Stroke Tom]

Wanted to get some ideas on why my bike has these "Spots O Spooge" (SOS) on the fender, myself (don't ask), the muffler, and anywhere around the back end of the bike.  2002 with fresh OEM piston/rings, well jetted, plenty of power, starts first kick hot/cold, etc.  One thing after riding with USMC500 I decided that I would cut off the tip off the FMF as I liked the look.  I then decided I really didn't like being "tipless" (no offense Oscar) but did not like the stock FMF "droop" so had a straight tip put on.  I don't think this is causing the "spots o spooge" but the exhaust is exiting straight out instead of down. 

Jetting is 168/stock 3rd clip/55 and I have tried lots of different combos.  Stock carb with stock reeds.  I have run the ratio from 40:1 to 80:1.  Less SOS at 80 but still there.  I run 10oz of TORCO octane boost with 91 octane CA gas for 5 gallons.  40:1 feels fat, 80:1 feels best.  I usually end up at 70:1.  Been in the motor a few times while experimenting with the bike and getting used to the 500.  No carbon, everything is nice and wet, looks great.  Plug is always black, maybe a little wet, and never fouls.   I always run my 500 a little rich here in the desert.  Have 45 hours of engine time.  Seems like it started 10-15 hours ago?  Do I just weld a 45 deg on the tip and not worry about it or is something up?  Is this normal?  No change in the power at all, bike has always run very well.

This is definitely an indication of running rich, even though you have set your jetting to "ballpark" specs. Chain fling wouldn't end up on the top of your fender so uniformly like it is in your picture. If you pull your plug at idle, your only getting an indication of your pilot/air screw adjustment jetting. To jet the rests of the circuits correctly, you need to throttle chop it and pull the plug at varying throttle positions to jet the needle and main. This is the correct way to find optimal jetting, but any significant change in elevation/temperature and you technically will have to make jetting adjustments.

In my opinion, leave it the way it is if it's running as well as you say it is. Run 40:1 (not 70:1!!), and wipe the SOS off after you ride. This is cheaper than rebuilding your motor due to a lean condition.

[Motorrad]

And you have it backwards.    80:1 is RICHER.  Than 40:1.      The way the motor sees it

[sandblaster]

Yep, anything that takes up the space flowing through your jets besides fuel makes a leaner mixture...
More oil flowing through the jets means less fuel is flowing through.
Less fuel entering the combustion chamber with the same volume of air makes a leaner mixture...
Here is some info from Motul in regards to their MX blend:

RECOMMENDATIONS
Mixing ratio : MOTO CROSS GRAND PRIX : 2% (50:1). In normal conditions decrease the percentage
by 0.5%.
Tune according to your own use.

[Mohave]

Not from the chain.  Running Motul 800, very impressed with this oil.  Going to try repacking the muffler as it may be saturated from my jetting experiments and 45 hrs runtime.  By the way the "SOS" is much less at 70:1, and the bike really seems to run cooler.  Never any coolant.  Today at 40:1, not riding particularly hard, bike spit out some coolant.  Thought that was kinda weird?

[2-Stroke Tom]

And you have it backwards.    80:1 is RICHER.  Than 40:1.      The way the motor sees it

Exactly, more fuel is richer. However, his spattering has very little to due with the ratio of fuel to premix. What I meant is that his carburetor jetting is too fat, and the excess fuel is not combusted causing the SOS.

[USMC 500]

Tom
Blaster
Motorrad...........

The 3 wise men have spoken.........Good lookin bunch of fellas too.

I just locked up my motor for being too lean (and stupid) so I'm gonna keep my mouth shut on all the jetting stuff.

[Motorrad]

Tom
Blaster
Motorrad...........

The 3 wise men have spoken.........Good lookin bunch of fellas too.

I just locked up my motor for being too lean (and stupid) so I'm gonna keep my mouth shut on all the jetting stuff.

I think I'm going to start a new section of the site called "usmc's jetting tips"

[USMC 500]

Tom
Blaster
Motorrad...........

The 3 wise men have spoken.........Good lookin bunch of fellas too.

I just locked up my motor for being too lean (and stupid) so I'm gonna keep my mouth shut on all the jetting stuff.

I think I'm going to start a new section of the site called "usmc's jetting tips"

I'll start off the new section with a thread titled........"Drop your jet sizes till the pipe glows and then you're good"!!

[2-Stroke Tom]

Tom
Blaster
Motorrad...........

The 3 wise men have spoken.........Good lookin bunch of fellas too.

I just locked up my motor for being too lean (and stupid) so I'm gonna keep my mouth shut on all the jetting stuff.

I think I'm going to start a new section of the site called "usmc's jetting tips"

I'll start off the new section with a thread titled........"Drop your jet sizes till the pipe glows and then you're good"!!

Or, "Fatten up your jetting until the pipe spooges, then keep riding and wipe off your fender"!!!!

[sandblaster]

I thought it was polish it till it glows, not jet it till it glows  

[conbread]

Lean is Mean!!!!   

[USMC 500]

When my CR was still a 250 I had a spooge problem......turns out it was excess build up in the pipe and silencer left over from when the bike was running rich.........Pull the pipe and silencer....maybe you just need to repack the silencer and clean out the pipe.

[Mohave]

Going to pull the muffler and clean/repack it tonight.  Pipe is pretty new so should be good.  If really gross I will take pictures.

Nothing like SOS to convince people to do their maintenance...by the way how many hours are you all going before you repack?