WHAT OIL AND RATIO ARE YOU RUNNING IN YOUR AIR COOLED 2 STROKE

Maxima Castor927
50:1
No
85 ATC250R and 78 RM125

Champion racing two stroke synthetic (formerly Duralube) 50-1 , no excessive smoking, Maico's radial to spider motors 250's and 490's.

I tried Maxima 927 because I liked the smell. Did it's job but burned super dirty. I could not believe the carbon on my piston and pipe in 8 hours. I switched to Amzoil 40:1

I run Klotz super techniplate at 40:1 with VP C12 in all of my vintage racers. Absolutely no smoking,super crisp and clean. Of course on my 80 YZ250G I also run 2 things you don't like---a Lectron and a PVL ignition which definitely helps too. But my guess is the same as yours, it sounds like you're sucking tranny oil .

i will just need to do a leak down test when i get time, but for now, i will try 36:1. never used maxima before so don't know if 40:1 is safe. the manual calls for 32:1 yamalube r or 20:1 with some other oils, but i don't know if the yamalube r was synthetic in 1980. i called the tech department of the mfg of the yamalube 2r and they referred me to another person so i am waiting for a reply back from them.

maxima did say i can definitely run their gear oil in the gas for a while without doing damage other than carboning up the system, so i guess if it is leaking from the trans into the engine, i could probably run 60:1 at the moment and be safe, lol.

Maxima K2, 40:1 in all of my vintage bikes both MX and trials. Maybe slightly more smokey than other synthetics at that ratio but very clean overall. I tried 927 but like a previous poster found it burned a little dirty. Plus I read it can sometimes ‘fall out’ in cold weather or mixed with some race gas. I run a 50/50 mix of C12 and non ethanol pump 91 so didn’t want to chance it.

Kaaden'sTheory wrote:

Maxima K2, 40:1 in all of my vintage bikes both MX and trials. Maybe slightly more smokey than other synthetics at that ratio but very clean overall. I tried 927 but like a previous poster found it burned a little dirty. Plus I read it can sometimes ‘fall out’ in cold weather or mixed with some race gas. I run a 50/50 mix of C12 and non ethanol pump 91 so didn’t want to chance it.

What are your mx bikes?

Do they smoke some all the time at all speeds?

Are you ever holding them wide open very long like in a desert race or a gp with some long straights etc?

I am racing in the elsinore gp in a week and they have two long 70 mph straights and the race is 30 minutes long.

I’ve ran it in assorted Maico 400s from 76-78, Honda CR480, Montesa VR250 and Cota 247 trials, and will soon run it my latest project a 77 Husky CR390. No cross country just MX and I don’t hold much of anything wide open very long these days..,

Kaaden'sTheory wrote:

I’ve ran it in assorted Maico 400s from 76-78, Honda CR480, Montesa VR250 and Cota 247 trials, and will soon run it my latest project a 77 Husky CR390. No cross country just MX and I don’t hold much of anything wide open very long these days..,

ok thanks. you can get away with leaner mixes on a big bore. it has been running fine with the 32:1 so i think for now i will just go with 36:1.

i have been running shell 93 e10 with 25% vp street blaze, and the street blaze has ethanol too. i just bought some ms109 today and will try that at 20% with the shell. i can't get non ethanol gas where i am but a little ethanol is not a bad thing like some people think it is. the biggest drawback is that it can attract moisture under some conditions. vp says the 109 makes the most power out of all their fuels because it burns the fastest but of course that doesn't mean it is the best for all apps which is why they have a bazillion different fuels but i think they could whittle a few out. i'll find out soon if the new master brew makes any difference in how it starts which isn't very easily at the moment but i am still working on that. the ms109 has 10% oxygen, but the odd thing about the ms109 is that it has the lowest rvp by a huge margin, which isn't good for starting at all but i will soon find out.

Bel-Ray H1-R, 36:1, VP-101 on all bikes the last few years. Clean running and no problems (knocking on wood now...) on any of our bikes.

In the early 70’s I ran Bel-Ray @ 50:1
Then in the late 70’s I ran HiPoint at same.
After that Spectro at same ratio.
Never any top or bottom end failures due to oiling.

I have two Honda 250s, and run Yamalube R at 40:1 and Sunoco Racing Fuel religiously. No pump gas with Oxygenates, Antiknock Agents, Lead Scavengers and Dyes, etc. When jetting correctly with good oil and fuel....silencers have a nice gray-tan tint to them and no spooge!!!

mxracer106 wrote:

I have two Honda 250s, and run Yamalube R at 40:1 and Sunoco Racing Fuel religiously. No pump gas with Oxygenates, Antiknock Agents, Lead Scavengers and Dyes, etc. When jetting correctly with good oil and fuel....silencers have a nice gray-tan tint to them and no spooge!!!

mxracer106 wrote:

I have two Honda 250s, and run Yamalube R at 40:1 and Sunoco Racing Fuel religiously. No pump gas with Oxygenates, Antiknock Agents, Lead Scavengers and Dyes, etc. When jetting correctly with good oil and fuel....silencers have a nice gray-tan tint to them and no spooge!!!

barnett468 wrote:
I can only dream that my pipe will ever look like that. Mine looks like the exon valdeze, lol..

LOL! They wet side crank seal will really create excess oil, but it looks like you have already solved that issue. Can you repack the silencer? Once they are saturated, they have no choice but to spit oil out. If you are running a slower rpm's on a 250, I personally do not think there is a need for 32:1 oil ratio. Maybe experiment with backing the ratio down in incremental steps, and continue to monitor what the plug reading looks like and how much excessive oil is spooging out. I only run race fuel for the fact that is it not polluted with unnecessary additives (not really needed due to high compression and pre-ignition issues), and it is always consistent. I only do mx with my bikes, so they are more so on the upper rpm range where more lubrication would be needed.

mxracer106 wrote:

I have two Honda 250s, and run Yamalube R at 40:1 and Sunoco Racing Fuel religiously. No pump gas with Oxygenates, Antiknock Agents, Lead Scavengers and Dyes, etc. When jetting correctly with good oil and fuel....silencers have a nice gray-tan tint to them and no spooge!!!

barnett468 wrote:
I can only dream that my pipe will ever look like that. Mine looks like the exon valdeze, lol..

mxracer106 wrote:

LOL! They wet side crank seal will really create excess oil, but it looks like you have already solved that issue. Can you repack the silencer? Once they are saturated, they have no choice but to spit oil out. If you are running a slower rpm's on a 250, I personally do not think there is a need for 32:1 oil ratio. Maybe experiment with backing the ratio down in incremental steps, and continue to monitor what the plug reading looks like and how much excessive oil is spooging out. I only run race fuel for the fact that is it not polluted with unnecessary additives (not really needed due to high compression and pre-ignition issues), and it is always consistent. I only do mx with my bikes, so they are more so on the upper rpm range where more lubrication would be needed.

Thanks for the info.

I repacked my silencer before i changed the seal and it immediately got oil soaked again and it smokes the same after i changed the seal. The silencer packing does not get hot enough to cause this amount of smoke even if the packing is soaked, plus it smokes from the second i start it which is long before the silencer gets hot.

The last race i was in 4 weeks ago with calvmx, i entered the novice class, and was in second place in front of i think scott burnworth and 15 other experts, intermediates and novices until some clown behind me went wot into a turn and centered punched me, so i am definitely floggin it reasonably hard, but certainly not as hard as warren reid on a 1974 fmf or dg built cr125, lol.

Today I am attempting to find the parts i need to do a leak test. If i find them i will post the results.

barnett468 wrote:
I can only dream that my pipe will ever look like that. Mine looks like the exon valdeze, lol..

mxracer106 wrote:

LOL! They wet side crank seal will really create excess oil, but it looks like you have already solved that issue. Can you repack the silencer? Once they are saturated, they have no choice but to spit oil out. If you are running a slower rpm's on a 250, I personally do not think there is a need for 32:1 oil ratio. Maybe experiment with backing the ratio down in incremental steps, and continue to monitor what the plug reading looks like and how much excessive oil is spooging out. I only run race fuel for the fact that is it not polluted with unnecessary additives (not really needed due to high compression and pre-ignition issues), and it is always consistent. I only do mx with my bikes, so they are more so on the upper rpm range where more lubrication would be needed.

barnett468 wrote:

Thanks for the info.

I repacked my silencer before i changed the seal and it immediately got oil soaked again and it smokes the same after i changed the seal. The silencer packing does not get hot enough to cause this amount of smoke even if the packing is soaked, plus it smokes from the second i start it which is long before the silencer gets hot.

The last race i was in 4 weeks ago with calvmx, i entered the novice class, and was in second place in front of i think scott burnworth and 15 other experts, intermediates and novices until some clown behind me went wot into a turn and centered punched me, so i am definitely floggin it reasonably hard, but certainly not as hard as warren reid on a 1974 fmf or dg built cr125, lol.

Today I am attempting to find the parts i need to do a leak test. If i find them i will post the results.

I think you are on the right track....keep us posted!

Also running Maxima K2 at 40:1 with Sunoco 100 for about 10 years.

I used to run 50:1 but felt a lot of pressure from engine builders to run more oil in my 125s at 32:1. Since I ride 125s, 250s, and an Open bike I just split the difference and run 40:1 in everything.

My bikes are jetted well and I don’t have the smoke problem you describe. The K2 doesn’t have that great 927 smell...but it’s way cleaner on powervalves.

wpark89 wrote:

Also running Maxima K2 at 40:1 with Sunoco 100 for about 10 years.

I used to run 50:1 but felt a lot of pressure from engine builders to run more oil in my 125s at 32:1. Since I ride 125s, 250s, and an Open bike I just split the difference and run 40:1 in everything.

My bikes are jetted well and I don’t have the smoke problem you describe. The K2 doesn’t have that great 927 smell...but it’s way cleaner on powervalves.

What years are your bikes?

If they are water cooled it makes a significant difference.

quiknic wrote:

Bel-Ray H1-R, 36:1, VP-101 on all bikes the last few years. Clean running and no problems (knocking on wood now...) on any of our bikes.

And exactly what yer and model are they?

mxracer106 wrote:

LOL! They wet side crank seal will really create excess oil, but it looks like you have already solved that issue. Can you repack the silencer? Once they are saturated, they have no choice but to spit oil out. If you are running a slower rpm's on a 250, I personally do not think there is a need for 32:1 oil ratio. Maybe experiment with backing the ratio down in incremental steps, and continue to monitor what the plug reading looks like and how much excessive oil is spooging out. I only run race fuel for the fact that is it not polluted with unnecessary additives (not really needed due to high compression and pre-ignition issues), and it is always consistent. I only do mx with my bikes, so they are more so on the upper rpm range where more lubrication would be needed.

Are they air cooled or water cooled?

barnett468 wrote:

What years are your bikes?

If they are water cooled it makes a significant difference.

Run the same in everything no matter air cooled or water. Why do you say the cooling system makes a significant difference on your premix?

79 YZ 400
83 Cagiva 125
88 Cagiva 125/250
90 KTM 125
95 KTM 250

wpark89 wrote:

Also running Maxima K2 at 40:1 with Sunoco 100 for about 10 years.

I used to run 50:1 but felt a lot of pressure from engine builders to run more oil in my 125s at 32:1. Since I ride 125s, 250s, and an Open bike I just split the difference and run 40:1 in everything.

My bikes are jetted well and I don’t have the smoke problem you describe. The K2 doesn’t have that great 927 smell...but it’s way cleaner on powervalves.

barnett468 wrote:

What years are your bikes?

If they are water cooled it makes a significant difference.

wpark89 wrote:

Run the same in everything no matter air cooled or water. Why do you say the cooling system makes a significant difference on your premix?

79 YZ 400
83 Cagiva 125
88 Cagiva 125/250
90 KTM 125
95 KTM 250

air cooled bikes can reach significantly higher temps then water cooled ones typically cam and different oil burns at different temps so a water cooled engine can get away with the oils that burn off at lower temps where an air cooled one might not under some conditions. It's rather complicated, but if someone is desert racing their air cooled 125 in 100 degree temps and hasn't seized using their particular oil at a relatively lean ratio, it is good info to know.

Many people riding trials bikes run 80:1 and sometimes leaner with no problem.

So, I got lucky and made up a pressure tester with my compression gauge hose and a radiator pressure tester I borrowed from an auto parts store and 2 expandable rubber plugs.

The results are that there is a small air leak of 1 lb per minute, however, the tester was leaking a tiny bit so that accounts for a little bit of the leak, irregardless, 1 lb per minute is not remotely bad enough to cause the amount of smoke I have. The piston also looks like new and there is zero blowby past the 2nd ring, therefore, it seems to me that the majority of the smoke is from running the oil a bit rich, so tomorrow, I am going to elsinore to test it with 38:1 and 80% 91 octane e10 shell pump gas and 20% vp ms109 oxygenated fuel then will do some high speed runs.

I will post as to whether it blows up or not, lol.

barnett468 wrote:

What years are your bikes?

If they are water cooled it makes a significant difference.

wpark89 wrote:

Run the same in everything no matter air cooled or water. Why do you say the cooling system makes a significant difference on your premix?

79 YZ 400
83 Cagiva 125
88 Cagiva 125/250
90 KTM 125
95 KTM 250

barnett468 wrote:

air cooled bikes can reach significantly higher temps then water cooled ones typically cam and different oil burns at different temps so a water cooled engine can get away with the oils that burn off at lower temps where an air cooled one might not under some conditions. It's rather complicated, but if someone is desert racing their air cooled 125 in 100 degree temps and hasn't seized using their particular oil at a relatively lean ratio, it is good info to know.

Many people riding trials bikes run 80:1 and sometimes leaner with no problem.

I ran Redline Synthetic for many years in my 250R at 100:1 with dead on jetting with no issues whatsoever. I only quit using Redline because I couldn’t find it locally any longer. No smoke, spooge or issues at all.

Let me add to the topic that using race fuel with LEAD will also prolong ring, piston and cylinder life, over unleaded fuel. I run a 50/50 mix of pump gas & VP C12 with yamalube R at 32:1. I raced 4 years with 12 events a year on one set of rings and piston on '79 YZ250. Plugs insulators are light brown as well as the piston crown. Jetting is spot-on. Even though the engine still performed well, here of late I replaced rings because bike was getting hard to start. Worn rings will decrease vacuum signal to draw fuel flow through the carb and into the combustion chamber, hence starting problems.

With air cooled engines having greater piston to cylinder wall clearace, wouldn't a richer mixture be needed for ring seal?

Sir Roostsalot wrote:

With air cooled engines having greater piston to cylinder wall clearace, wouldn't a richer mixture be needed for ring seal?

The difference in compression is actually immesaurable for all intents and purposes but some people that don't really know how it works but read something on the internet that is wrong or misleading simply repeat it to others.

More oil than necessary can also reduce hp and slow the rate at which rpms build but it seems that some of the people that believe a little more oil will make a measurable difference in ring seal seem to either not know that or think an insignificant increase in ring seal is more important. Some also seem to completely miss the fact that compression can be increased by simply reducing the size of the combustion chamber.

Some also miss that fact that there is no way they are capable of riding their bike as fast is it can be ridden, so even if they got another hp by better ring seal, it ain't gonna get them around the track one bit faster and they should simply practice more to go faster instead of worrying about something so insignificant.

More oil also reduces the amount of power (btu) in the fuel.

Some people that worry about less ring seal with less oil on a 2 stroke don't even think about it on their 4 strokes, lol.

wfoyz250 wrote:

Let me add to the topic that using race fuel with LEAD will also prolong ring, piston and cylinder life, over unleaded fuel. I run a 50/50 mix of pump gas & VP C12 with yamalube R at 32:1. I raced 4 years with 12 events a year on one set of rings and piston on '79 YZ250. Plugs insulators are light brown as well as the piston crown. Jetting is spot-on. Even though the engine still performed well, here of late I replaced rings because bike was getting hard to start. Worn rings will decrease vacuum signal to draw fuel flow through the carb and into the combustion chamber, hence starting problems.

"Let me add to the topic that using race fuel with LEAD will also prolong ring, piston and cylinder life, over unleaded fuel."

I have never seen a scientific test that showed this. If you have, please post it.

Lead was originally added to fuels to protect valve seats in automobile engines, while it may also mitigate piston and ring wear and help with detonation, in two strokes it shouldn't be a factor as long as your running fresh high octane gas and your carb setup is correct you should get as good a performance as the exorbrantly priced "race fuels" to the average rider.(Not wanting to start an argument for or against race gas here , just sayin) 32-1 may have worked back in the days of Blendzall and primarily castor or petroleum based two stroke oils but the newer generation of oils is designed to run at leaner ratios which does increase performance and reduces carbon build up and the "spooging" you describe. At the least I would try running 40-1 and even 50-1 if you can bring yourself to do it. Also what is your jetting like?? May be that the main is too rich. Perhaps experimenting by dropping the main jet incrementally and taking plug readings might lead to a solution. You might also check your reeds to see if they are chipped or broken or even not closing fully.The latest generations of KTM two strokes were recommeded to run 60-1 ratios with their "new" Mikuni carbs so certainly leaner oil ratios are something to consider. Good luck getting things running right!