0007

I don't really trust the machining tolerance on stuff not built in Japan My beta's are tight as heck, the bearing would hardly turn in the wheel but felt new after removal so I suspect there could be some clearance issues I agree with the comments about regreasing the bearings, I blow out the stuff that's in there and replace it with optimol grease, that stuff is incredible You might want to find the correct spec for the axle spacer and measure yours, it could be collapsed from over torquing at some point or just out of spec

So I have enjoyed this discussion Who can tell me what the answer to the original question is We need a definitive specific answer you know, this is the Internet here, we need to be accurate LOL

I was going to mention Stoich but it is entirely a jetting thing and not a oil ratio thing I think the engine would not suit a pyrometer but would certainly be easier to tune with an 02 sensor and a gauge on the bars, it would take a heated sender and all but....it wouldn't work in a section, you would have to check numbers at certain throttle openings, set and forget I agree with wanting to keep the A/F ratio closer to12.5:1 as response is what we want, over 14 is really for fuel economy and clean emissions As was mentioned before a lot can be learned from the factory's oil injection ratios, interesting that they go from practically no oil to 30 or 40:1 or maybe more but then again injection oils are somewhat diluted to reduce viscosity Tells us that a straight ratio is really a compromise on both ends Another note, Yamaha pre mix 2 stroke OB's run at a factory recommended and warrantied 100:1, these motors tolerate ridiculous loads and runn at WOT for extended periods, but max rpm is 5500, maybe ratio relates more to RPM than it does to load I remember hearing about Jeremy Mcgraths last years at Honda on a 2 stroke and his bike was making something like 70 HP, they were running 25:1 and that bike didn't smoke even a little bit I bet those engines were hand built masterpieces

And for the record I agree that a little more oil isn't going to cause an expensive failure so to err on the side of caution is not likely to cost you like doing it the other way

http://www.freeengineinfo.com/two-stroke-carb-tuning.htm http://www.smellofdeath.com/lloydy/piston_diag_guide.htm I could probably find a bunch of references to using the carbon on a piston as a tuning tool It's got nothing to do with the oil, the fuel has more detergent to decrease gum and coke than the oil does and it makes up for pretty much 100% of what is burned in the combustion process The temperatures involved on the piston crown are probably high enough to burn almost anything onto it and it's the underside that is the clearest indicator Actually increasing the amount of oil will lean out jetting and cause slightly more carbon buildup Anyway, back to oil ratios LOL

I mentioned it before but may have been missed If you don't have carbon forming on your piston crown you are too rich, it's simple If you want to make power and run clean, you need correct or at least reasonable combustion temperature This will put carbon on the crown It's not an oil thing But this might not be easy to do on a trial bike, it's probably an engine that needs to be jetted by feel rather than this way Snowmobiles are the ideal example of 2 stroke jetting simply because of their CVT transmission

I agree that there will never be a definitive answer and the answer wont come from manufacturers, I spoke of variables and one that I never mentioned is the rider Let's say that a manufacturer releases data on eangine wear characteristics, how heavy is the rider?, a 140lb rider would put drastically less load on an engine than a 240lb rider And how about a 140lb rider who rides sections as opposed to a 240lb rider who does a great deal of hill climbing or vice versa Engine testing can only be done on a dyno under controlled conditions with hand built engines at near perfect tollerance, humans cannot do this stuff unless it's the same human in identical conditions who never gets tired or a gets a cold and takes it easy one day, rides in the same terrain at the same temperature altitude and humidity levels etc etc, now imagine this guy putting a couple hundred hours on each brand of oil at each ratio with a fresh spec engine hand built by an engineer each time..........this is the reason I can't take one persons comments about "I used Yada yada oil at Yada Yada ratio for 5 years and have no engine wear" I'm sure there was guys in the 60's using 10w40 motor oil and having these same discussions With regard to carbon build up on a piston crown, the only real way to check jetting is NOT with plug color, it is by the carbon ring on the piston crown, 2 strokes make their most power when they have the right combustion temperature, the fuel SHOULD burn onto the crown to within 1cm of the edge of the piston If you can see clean aluminum it has nothing to do with oil, it's simply that you are jetted too rich Additional note, the shock wave from detonation or pre ignition will tend to remove the carbon on the piston crown

The variables would be and not limited to High octane fuel, low octane fuel, octane boosters, engine condition, state of tune, modification, damage, plugged up muffler, dent in the head pipe, leak at a joint, worn jet needle, main jet size, winter fuel or summer fuel, (yes they are different in certain markets), age of the fuel (2 weeks in a Jerry can and the light ends are all vented to atmosphere unless you have a non vented steel container in a cold place) Air temperature, engine temperature, thermostat problems or just out of tolerance, air filter cleanliness, air screw setting, float height and or float needle wear and altitude of course etc etc There are no 2 bikes identical as every bike has a random number of the above going on at any given time And a comment on oil accumulation in the bottom end, yes and no, the oil would not separate from the fuel, it stays in suspension, considering the violent turbulent conditions within an engine, nothing really sits around long, it's possible for fuel and oil to accumulate down there under certain conditions but inevitably it would result in a rich condition in the combustion chamber at some point, but again, oil is only 2% of the mix I would say that any stuff coming out the back would be a combination of fuel and oil mix, it would take a chemist to separate the oil from the fuel And by the way, I agree that I don't really want to breath the stuff, much of the "fuel" we buy is a chemical mix, these are proprietary blends and no one is required to tell you anything more than the alcohol content

When in doubt as a last resort, burp the banjo bolts, you will often find air there And I agree with baldilocks on pushing the piston back into the caliper, just watch that you don't over flow the master and make a mess and once you have the pistons pushed back in put a clamp on the caliper and bleed the system if it still feels mushy

Ahhhhhhhh, I get the point now exhaust temperature is really meaningless as this would be a combustion temperature thing THEORETICALY Combustion temperatures are pretty equal across the board on most engines but there are far too many variables so two identical models could be very different Ideally all of the combustible material in the 2 stroke oil would be consumed and no real oily goop would migrate into the exhaust, likely you would have substantially more unburned hydrocarbons from the fuel than you would the oil given that 98% of what goes into the cylinder is gasoline of suspect quality and the fact that a 2 stroke has a lot of abnormal combustion in a day But again, the variables, only the lab that the engine was designed in could test this properly

Thanks billy, I can't answer the question you asked but I wonder if the question could be asked differently If you mean "what creates more energy upon combustion in an engine" I bet the answer would come from a deisel tech, probably a few of those guys on here I bet the answer is quite different from just setting both on fire, both float on water so they are a pain in the butt to put out with water so they take away the oxygen with chemicals or foam 2 stroke oil is not meant to be used to improve horsepower, if you ran straight gas the engine would make the same power (for a short while) some 2 stroke oils or portions of the oil are not really burned off Let's say something like Molybdenum for example, I doubt it would be consumed in the combustion process, it would just blow through the engine

Perfectly understandable, anything you buy from Macdonalds has so many preservatives that even the little bitty remnants from the drink will cause the engine to be preserved forever, ever seen a cheeseburger go moldy?, french fry turn green? ....... Maybe we need some of that deep fryer oil they use huh..

In all that I failed to answer the question, 80:1 Another point I have seen in the past, misdiagnosis is very common A skirt seizure for example is usually due to loss of piston to cylinder clearance (too many causes to list) Rod brg failure is usually due to detonation etc etc More oil wouldn't stop either one of these from happening as oil was never the cause, so oil cannot counter the effect I enjoy these kind of discussions, and I like that this forum has no bad attitudes that like to fight and flame

I think this is an un answearable question simply because every one has their own opinion Usually it's because "I have always done it like this" so it's more habit than science My background is 30+ years in the industry, much of which i was a service tech and a decade of service and warranty with a major Japanese manufacturer I can say that I have never seen oil fail regardless as to how much you paid for it, it would appear that if it's there it works, even lean ratios seem to let an engine live, if you have the cushion, you have the cushion, you can't really have more If metal touches metal you have a failure, end of story, you don't get an engine that wears more rapidly than another because of oil type, again metal contact welds metal as quick as 60 cycles depending on load of course Most failures are probably fuel related or other mechanical problems The issues would be ring seal, more oil makes better sealing, no doubt about it And carbon buildup, which means more is not better The only time I have seen oil actually cause failures is when the incorrect oil is used, say marine oils which are low in ash, these oils are made for low revving cool running engines And old school types who insist on 20:1 with modern oils, carbon build up can increase compression even to the point where the piston contacting the carbon can cause a knock or even rod failure, also plugging up the exhaust port changing port timing So a decent correct spec oil at a reasonable ratio is going to work fine I had a detonation in my 07 Rev and ran a couple of tanks through with Ring Free and the deto went away, tells me I had a carbon issue So there's my opinion, I have seen a lot of broken stuff I'm my Carreer but I doubt everyone will agree with me LOL

Or take it to a shoe repair guy and see what he can do for you

Ya you know, it would be interesting to see an off road trials version of that thing huh

It means the needle is not sealing perfectly to the seat, the fuel exceeds the max fuel height in the carb and it comes out the overflow To a certain extent it is fairly common but it depends how bad it is, in a perfect world you should be able to never turn off your fuel and the carb would never leak but..... You may need to replace the needle, another trick is to use a little bit of lapping compound on a Q tip and gently lap the seat The other thing I hear is that you should not use the one way valves that dirt bike guys use, they let pressure build in the tank and this can push fuel the only way out which is past the needle

Maybe you don't quite get how a filter works, the oil IS the filter, the foam just suspends the oil It it's very thick but has a carrier that evaporates so it goes on thin and afterwards it gets gooey There's no engine or gear oil like it

Just curious but why would you want to use something else?, it's not exactly overpriced and a bottle lasts a long time Air filter oil is tacky like Dave mentioned and wont settle to the bottom of the filter It wont gel if water gets in it, it won't catch fire I don't think there is a suitable alternative

Outlaw Dave beat me to it, he's got what you need in stock

I have troubles with that too, I dab when I don't really need to dab I think finding something that you will slip on predictably and ride it repeatedly, like a rock on an angle that your tire slips off, at least you could get used to the sensation of the back moving around I also have troubles with running the rear tire over an obstacle while in a tight turn, I think that just takes practice

I pack one of those meal replacement milkshake things, a granola bar and lots of water I remember a saying, "if you're thirsty, drink water, if you're not thirsty, drink water" Joint pain, headaches, and lots of other symptoms can come from dehydration, once you get dehydrated it takes hours and hours to rehydrate, you cant just drink a bunch and get over it Same as food, you need to snack before you get hungry

I have had good luck with both the oven and the heat gun Put them in the oven at a bit over 100 degrees, then pulle them out and do them up real tight and walk around and streach them Also any tight spots use a heat gun and again put them on tight and streach them Sometimes 2 pairs of socks works but put em on uncomfortably tight and do squats and stuff to loosen them up Works great, will almost completely break them in with about a half hours work

I actually wonder what wider would be like I have long arms

I don't think weight is much of an issue anymore, they ae at minimum weight and inside the transmission is kind of a good spot for heavy parts