Another two stroke oil thread. Facts vs info vs real world?

i bought my 88 xc 250 as a NOS bike..it had run well over 200 hours on a stock top end..almost its whole life has been klotz super techniplate and its whole life has been 40:1..has really never lost any compression but i pulled motor and replaced with 430 for now.. this is only out of fear of piston fatigue..i would have no problems running a bike at 40 unless it was raced hard, where 32:1 would probably be wiser. 50:1 would be better for more casual riding..

the amount of oil mix you use is pretty much totally dependant on the load/rpm you run the bike at..

I used Quaker state 30wt motor oil in my dart go kart in the Clinton 2 1/2hp panther engine. This was the late 1950's. There wasn't two stroke mix available back then. We killed every mosquito/skeeter in a square mile.

My riding style was ripping most of the time on my 390cr. I'm between the 1/3 to the upper end WOT most of the time. I would brapp, brapp, brapp while shifting gears in between. She sounded like a 500cr. The rear wheel never stopped spinning unless I shifted. I would rip up the straights. Near the top of sixth gear if I wicked it more the front wheel came up. I LOST 60lbs in three months on the 390. Better than hitting the gym. Making three passes at the dam easy trails I could just put the bike on the trailer at first. Bike "1" human "0". I threw everything I had at that bike and it wanted more. Big bores rock. I don't play ride. I'm in it for the exercise. I was anyway.

Bill,
There is a guy on this forum, who was a 2T engineer at Husqvarna and he has seen the data recorded from multi time World and GNCC Champion Juha Saliminen's bike during World Enduros... He wasn't at WFO 5% of the time in a Special Test. I'm sure you were winding out your 390, but a lot less than you think per mile....

Ha Ha! I run my bikes wide open once a month or so, usually during the new moon phase, that's why it makes a new moon sound when it's on the pipe.

It makes sense to me that riding style is as important as fuel/oil ratio and jetting. If you're pulling a grade at high RPM with 1/4 throttle the engine is most likely going to be starved for lubrication while under load whereas at lower RPM with 3/4 or more throttle would provide more lubrication, not to mention lower RPM means less heat.

Heres a section from an HVA automatic owners manual. Number 1 under Warning emphasizes not to over rev in a small throttle position. I think this would apply to most all air-cooled 2 strokes.

that applies to all two strokes, not even just air cooled ones. the engine is only going to get what lube you feed it with the throttle.

True that 2 strokes that are other than air-cooled also rely on premix for piston lubrication. I guess what I was thinking was that liquid cooled 2 strokes are less susceptible to overheating and seizing so they're not as prone to be damaged when piston lubrication is temporarily reduced.

The piston can get by with very little oil, it's the crank and rod bearings that will suffer when you go with less oil. For example if you have a really small pilot jet like on a 125 and you blast down a logging road wide open and the chop the throttle you go from a high rpm high load and basically shut off the oil and also the fuel helps cool things off. At this point all the bottom end gets is going through a very small pilot jet which is pretty scary. The same applies to a long downhill with the throttle shut off. In these situations it does some good to pull in the clutch and blip the throttle to give the bottom end some fresh oil and cool fuel. Too lean on the pilot will seize a rod bearing faster than any other situation besides forgetting to put mix oil in your gas.

Wait while I go get some popcorn!

I have a 50cc motor in my mountain bike, a Grubee GT2B Round Head, black powder coat.

It has a chrome liner.

One time I held that motor flat out, slight downhill for about 3 kms.

I had left my Girlfriends house after some horizontal dancing and a few drinks.

I was in a very good mood, on top of the world, wasn't thinking straight!

When I stopped at home the motor was that hot is was actually smoking.

I still use the motor, it is in another frame, and it still has good compression and still sounds healthy.

The oil,

Opti2, 100 to 1.

there are only a limited no of oils you can run at those ratios.

I always blip my way down from a high long winded revving.

I been running the husky on 80 - 100:1 using the kato oil motorex fully synthetic. I have used silkolene in the past as well.

its getting a teardown after 5 years of flogging on the original piston and rings (they looked fine when I recoed the bike so back in they went )

I noticed ol mates400 has a poo loadmore comp than mine so its time for a refresh... still goes hard as the other bike.

Hey guys, not sure if this is the right place to ask but I'll be racing my new 2016 TC250 next year and have some fuel questions. Ive been riding honda 250 4 strokes my racing career so dont have experience racing 2 strokes. I've got 5 hours on my bike so far ( taking it pretty easy) and bought AMSOIL dominator mix oil and mixed 60:1 as per the manual with 97octane dyed pump gas ( no ethynol). Like i said ive been taking it pretty easy to break it in before I start beating on it at the track and I noticed oil coming out of the pipe joint (expansion chamber-silencer) . People are apparently mixing 80,90,100:1 with the AMSOIL saber and i was wondering if anyone is getting away with this under racing (Motocross ) applications (not just trail riding)? The plug hasn't fouled or anything trying to decide if its too much oil, riding on mild setting or if i should use a different mix oil.

Being a 250, you can probably get away with less oil, especially if you're not wringing it out all the time, but I wouldn't do it.

stick with the 60. as you start to flog it more, the oil will dry up. as the bike runs in, you may need to fine tune the jetting a tad (new twoies are pretty good out of the box though) Get used to some oil splooge as it will appear from time to time.

I only know of motorex oil being a "deep base" oil allowing higher mix ratios but amsoil may also be one... I would find someone who is mixing at that ratio and ask them . I have run motorex at 100:1 successfully in my 2010 300 kato. the aussie kato importer uses motorex at 100:1 and has done for years.

I am currently using maxima castor 927 at 40:1...smells good!

Keep it at 60:1 if you get spooge use a lower flashpoint oil, from what I gather in the states amasoil is the bees knees so you can't go too far wrong.
Personally I don't go less that 50:1 but I've an old smoker. These modern bikes like less oil but 100:1 would far too lean an oil mix for me.

Remember
1:1 is one gas one oil
50:1 50 gas one oil
100:1 is seized lol no it's all gas a drop of oil

So the higher the ratio the less oil you use.

Amsoil Interceptor has a lower flash point then Dominator so if you're going to putt around Interceptor is a little better choice.

Newer bikes nikasil cylinders with chrome rings.
Older bikes castiron sleeves with chrome rings. Tighter cross hatch on the final hone the more honing grooves to hold more oil.

New modern two stroke oil is for nikasil cylinders. Read the label some have a castor blend added for the castiron sleeves. The nickel castiron sleeves can be glazed from wear harder than chrome. Disc brakes are castiron/nickel on your cars.

I'm going to run 20:1 maxima 927 that's formulated for the castiron sleeves. But in the open areas I'm on the high end of the throttle just ripping.

It's a combination of using the correct two stroke blend of oil, the right ratio and jetting to it.

One of my co workers beats the snots out of his 89 Honda 250cr. It's orginal and he runs 16:1 ratio. He runs it hard. A tad more oil.

Ok thanks for the input. I had an 08 RM250 for a bit i ran 40:1 maxima Castor and really liked it. Lots of talk about it burning dirty and gumming up the power valve, so Im trying this AMSOIL with my new Husky. We'll try riding on the pipe at 60:1 once the snow melts and see if it stops spewing oil