Synthetic pre-mix and pre-mix ratio?

[HUSKwKDX]

How high a pre-mix ratio can you (safely) go with a fully synthetic oil? This web-site says 80:1 to 100:1 (go to bottom of page) ...

http://www.gasgas.com/Pages/Technical/Exhaust-clean.html

Any comments? :confused:

 

[mlhend1]

You first!!!

 

[Braahp]

I totally believe in synthetic oils but "there is no subsitute for quantity vs. quality". I'd go 40:1 or 50:1 at the most.

 

[2001yz250]

I think it should be based on the oil manufacturer's recomendation rather that the engine manufacturer's.

 

[Lew]

Redline synthetic racing oil @ 40:1. Comes in 16oz bottles, so just drop one in with 5 gal of gas and yee haw..
Lew

 

[HiG4s]

80 or 100:1 is correct with a full synthetic on the lower reving trials bikes that site is talking about, but not on higher reving MX or Enduro racing bikes.

 

[Sage]

oil ratio and engine rpm's are hand in hand, a race built 60 would not live with 100:1 mix but a low rpm, low & mid built 500 would run for quite a while. the most important thing is to set the bike up for its intended use, if you never plan on revving the thing up much 100:1 will work, the plus for woods use is less drool & it allows you to run smaller jets and achive more distance out of a tank. I have ran 100:1 just to see, but I do the same thing as Lew, 1 can to a 5 gallon gas jug, its easy and I'm lazy like that........

 

[HUSKwKDX]

Thanks for the replys. The reason I ask is because I want to understand why my bike produces so much oily spooge in the S/A. I'm pretty sure I've got the jetting dialed in. I really don't want to go any leaner ...
'90 KDX200, FMF K-14, main=152. pilot=42, NR1173 #1, AS= 3/4 out. Sea level, mid sixtys temp, humid ~60-80%. Before I RTV'd the screws on the stock S/A, oil would drip out all over the s-arm, brakes etc. plus I have to re-pack what seems way to often. Any suggestions would be greatly appreciated. Thanks.

 

[mlhend1]

Your saying I may run my Castro TTS Full synthetic oil at 80/100 to 1 without harm to the engine? Response to http://www.gasgas.com/Pages/Technical/Exhaust-clean.html



Mark,

Yep. I know it sounds like I'm inviting engine failure, but a full size Trials engine is designed differently and subjected to a different set of circumstances and operating conditions than most other racing engines. I come from a RoadRace and MX background, where 20:1 and 32:1 are the norm, so I was also skeptical at first. The Gas-Gas factory recommends a 100:1 ratio, but I personally believe in running a little more oil in my premix, so 80:1 is what I run in my big-bore Gas-Gas. I have built many hundreds of Professional racing engines and have always considered reliability of the utmost importance, as, "if you don't finish, you can't win". Full-synthetic Castrol at 80:1 will give you excellent results.



Jon

 

[Simon Fuller]

I use Motil 800 fully synthetic @ 40:1 with no spooge. I ride mainly tight woods (and I'm slow :ugg: ).

Check out the video on the GasGas site - cool :cool:

 

[r.2 stroke]

Yeah,i agree with what Sage has said,and like Simon,i use Motul 800 2t @40:1,same type of riding as him and hardly any spooge.
Sounds like a jetting type of problem,easy to fix. :D

 

[KDX'r in IN]

I use Bel Ray MC-1 at 50:1..... on track or trail no problems

 

[fishhead]

excessive spooge is from too rich jetting which keeps combustion temps low and prevents the oil from burning in the combustion chamber and ends up drooling out the silencer. It can also be aggravated by long periods of idling around and loading up the crankcase with oil.

The oil manufactures know what mix their oils are effective at. most kdx's are ok at 40-50:1 with good quality oils. Spectro says run the gold synthetic blend at 40-60:1 depending on application but run the SX full synthetic at no less than 40-44:1.

Oils that burn at low temps produce less spooge but provide less protection in extreme conditions.

The best way to minimize spooge is jet the bike.

 

[Dazza]

Castrol TTS

1989 KDX200 castrol TTS 35:1 Main 155 Pilot 45 1173 needle 3rd pos
BR9ES plug No spooge fouling
The castrol is cheap smells good to.
Get just a little smoke between gear changes.

 

[jtorres]

Who has tried Blendzall castor oil and at what ratio, Iride mainly tight woods and high relative humidity around the 80s

 

[Lutz]

Blendzall was the almost the only oil my bike was run on for about the first two years of its life. Mix was 40:1. Since then the oil has been Amsoil at 40:1 to 50:1. When the bike was taken apart, for the FIRST TIME EVER this winter, the bottom end was all in spec and the powervalves were remarkably clean. Spooge has never been big a problem, even with stock jetting.
IMHO, Blendzall, regular Amsoil and Amsoil 2000 are absolutely TOP OF THE LINE.
Regards,
Lutz

 

[fishhead]

Blendzall is still around? I haven't seen a can of the stuff for 30 years!

 

[TexKDX]

Hey, even at 80:1 on Motul 800 my trials bike will spooge up the pipe from all the putting around we do.

No matter what the mix, you have to get the thing hot enough to burn out the excess that accumulates. I run the Monty WFO in 5th dragging the brakes 3 or 4 100 yard passes. That gets it hot enough to burn it out.

Some WFO drag races in the open with your buds is a good way to keep your woods bike cleaned out if your normal riding does not include much sustained high rpm under load. Lower gears and high RPMs won't do it - the wind resistance at higher speeds is what creates the load and builds the heat.

Oil amount differs based on the use of the motor and quality of the oil. Some guys run the 100:1 amsoil. I have a friend that runs it in his Rotax 503, a air cooled twin used for ultra-light aircraft. It gets lots of sustained load and he's had no measureable wear at 100 hours of run time. Amazing.

On the other end of the spectrum, dyno tests on shifter cart motors, the highest sustained output load you'll put on a 125 motor, show that the engine will keep making more HP as you add oil right up to 16:1, then power starts to go back down.

Netting it out, for your average woods application you are in pretty good shape at around 50:1 with a decent synthetic or semi-synthetic motorcycle-specific premix oil. Bel Ray, Yamalube 2R, Motul 600 or 800, Silkolene, Golden Spectro, etc. will do the trick.