dan williams

Whatever works for you is fine. It's not a cleanest piston competition. ;-) I've never suggested anyone recommended 100:1. I've only said that I've run that lean without problems but I also run $15/gal fuel so maybe that helps keep my motors happy. Certainly keeps the VP dealer happy.

I've found after four years of riding most weekends a set of rings freshens it up a bit but even that isn't a necessity. Trials manufacturers don't sell a lot of pistons.

and that sir is a much better answer. Thank you.

You're #1 You're #1 Nice historic find. Seems to be missing a few parts. I had an Armstrong with frame #853200001. It is kinda neat knowing you have the original.

Hey heffergm if you're riding Meriden next week you can take a putt on my bike and tell me if it's down on power. Also what you think of my clutch which has been modded and uses the 6 fiber plates from an '08.

The internet yelling of FACT doesn't make it so. Otherwise a sure way to more horsepower would be the addition of oil to the fuel used in a four stroke. The facts are more likely a certain amount of oil will do all those magical things you espouse but more than that builds up and carbons ring lands, fills exhaust systems with spooge and smokes out the neighbors. Much of the "factual" information comes from two stoke GP work done by Yamaha in the 70s. It was good work but it is also considerably out of date as well as being focused on 12,000 RPM road rockets. Sherco and GasGas recommend well into the cautious zone of ratios. By the same token I would bet they also have similar maintenance regimens to Beta which expects you to clean, adjust and lube damn near everything after each ride. Maybe for a factory rider with his own mechanic but it ain't gonna happen for Joe Sunday rider. Found this interesting bit but there is more on the web; http://www.gasgasrider.org/forum/showthread.php?t=1296 I suspect this is going to be the norm in a few years much like my Subaru uses 0W-20 oil, not because it has superior lubricating properties but because it ekes out a few more miles per gallon. I have, in older bikes, had a muffler fire. I didn't try telling it there was insufficient oxygen for it to burn to see if that put it out. I'll try if it happens again and let you know the results. There are a lot of people running 80:1 and 100:1 without problems. As for me, my bikes make plenty of power, last for years and don't get me punched in the head by the guy behind me in line. I use good quality synthetic and VP C-12 race fuel. If you run crap gas then yes a lower oil ratio is probably a good idea but in that case you're probably running "Bob's quality outboard oil for two stork motors" anyway. I don't have to de-carbon my engines every year like I used to at 50:1, I don't have to futz with plug heat range anymore and the only major engine work I had to deal with was new main bearings on a bike that sat in storage for years while I played with a newer bike. I'm pretty sure that wasn't an oil issue as when I put it in storage I filled the tank with 50:1 race gas and occasionally started it leaving the choke on to intentionally oil the snot out of the engine. Even that smokey treatment didn't prevent moisture from bunging up the mains.

We learn by doing. Is it a Mikuni or Keihin? They have slightly different disassembly procedures but all two stroke carbs used in trials are pretty similar. The reeds are simple to check once the carb is off just undo the four bolts that hold them into the inlet tract. If they are not broken or held open more than just a crack they are OK. Usually if a reed is broken the engine won't idle because the intake port timing expects reeds to be there. You may have damaged a crank seal causing engine oil to leak into the crank chamber below the piston. The crank seal test is probably beyond you at this stage. Did you purge all the water out of your exhaust? If you've got water in the pipe it may not run quite right and smoke as the oil residue in the intermediate muffler and final muffler packing dry out.

This may be a stupid question but does it rev cleanly despite the smoke?

Dude decafe.

Just as manufacturers jet on the side of caution they also spec oil mix conservatively. When engines were air cooled and the first synthetics claimed you could mix them at 50:1 the cognoscenti declared it heresy and prophesized a great cataclysm of smoldering wreckage as every engine in the land was simultaneously destroyed. Now engines are water cooled with hard chrome plating directly on the aluminum cylinder with digital ignition curves. The hot spots that used to develop in iron sleeved cylinders simply don't happen and spot thermal runaway that used to require oil as a coolant and lubricant just isn't a problem anymore unless something is drastically wrong. Think about it, a highly stressed MX engine that is running at full throttle a significant amount of time blows most of its oil right out the exhaust. The little bit that sticks to the cylinder wall is sufficient to keep it from sticking solid so in practical terms it's probably getting a lot less oil than that 50:1 number would seem to indicate. On my trials bike running at 100:1 I can putt for a while and after a long fast trip between sections the bike is smoking because it is purging the excess oil that is pooled in the crankcase. 80:1 is sort of a compromise for those who are tired of being the smokey bike but not quite ready to go full lean. All this is academic though because if you are happy the way your bike runs with a higher ratio then use it. I may have the cleanest running bike in the woods but I still get my clock cleaned by guys on twin shocks belching smoke. I just hate to be behind them in line. It's all good. Let's play!

I flipped the top hats to reduce preload and swapped out for the older clutch pack with all six plates the same.

Yeah about 1 1/2 out. The Keihin's are moisture sensitive due to the very small passages in the pilot circuit. If it runs OK at low throttle you're OK. If you have poor idle and not smooth response off the bottom end then it's time to pull the carb and disassemble, blow out with compressed air.

I have seen pipes loaded with spooge from running a rich mixture of oil get very hot from the oily goo igniting. The pipe get much hotter than in normal operation, smokes like a coal locomotive and has to be dealt with in relatively quick order or surrounding materials suffer. It's a lot rarer now than with the old air-cooled engines but it can happen if your engine isn't tuned properly and you're heavy on the oil and run full blat for a long time. To be honest I can't remember the last time I saw a trials bike fail from lack of lubrication. The engines are just so much better now.

Isn't it kind of interesting the way these threads run in clusters?

Try the penetrating oil first. You've got nothing to lose and it might save you some crinkies.

Not gonna be a lot of mosquitos in your woods! At least your buddies will know where you are.

70:1 is a super safe bet, I run as high as 100:1 on Bel-Ray HR1 without issues. The low-revving water-cooled electrofusion bore engines are a lot more tolerant than the old aircooled engines. Kinda depends on how you ride, more oil if you're going to be flat out trail riding but less for real trials plonking. Even 80:1 will puddle in the bottom of the crank at trials speed.

After I got it apart I took emory cloth to the hole where the hex adjuster comes through the cap. I think the fit was tight to begin with and corrosion mated the two pieces of aluminum together. Now that you've reminded me of this I think tonight's project will be to take the cap off my '13 and grease it up proper while it still moves correctly.

ATF shouldn't affect the shifting unless it is causing significant clutch drag. My question was aimed at finding out if you'd flushed it with something that had a "seal saver" component to it which softens seals (read deteriorates). ATF is favored by the guys who like sharp clutch action but it won't hurt the transmission or make shifting more difficult. Any good motorcycle gear oil intended for wet clutches should work fine. When the motor is not running is there a noticable difficulty moving the shift lever?

I had a similar situation with my '08 and it took some serious torque and a blowtorch to free it up. Eventually I heated it to the point where the o-rings turned to carbon before it would move. You might try a different approach and throw some penetrating oil into the cap and let it sit for a while to see if it helps.

Awesome. It's all about the fun and it sounds like you improve each time. Well done.

What did you flush it with?

Damn that is a good looking machine!

Sad to bump this thread with the news that Peter has passed on. I stated watching his youtube channel and found him to be a wonderful story teller and commenter on the human experiance. Covering everything from making ox tail soup to his description of learning about sex in an air raid shelter during the war from "Althea" who Peter described as "a kind girl". As "geriatric1927" Peter left a wealth of stories and insight on youtube that is a priceless legacy. I really wish I'd gotten to meet the man.

It is supposed to be a closed system under pressure. Think of it this way, the greater the difference between the coolant and the ambient air the more efficient the cooling system. Water boils at 100C at one atmosphere of pressure but at higher pressure the boiling temperature is higher than 100C so the cooling system is more efficient. That's why a pinhole leak in a cooling system is a problem. Not because it leaks fluid but because it depressurizes the system causing the coolant to boil. The coolant reservoir is meant only to supply coolant to replace lost fluid when the bike cools down again and the pressure in the cooling system becomes slightly less than atmospheric. This allows the system to replenish its coolant without sucking air into the system.