2-Stroke Question

[ATC crazy]

I have been around thumpers all my life and I am thinking about getting a 2-stroke this summer/fall. I will be getting a job this summer for a ATC/TRX250R, and it will be my first screamer and I have a few questions. 1. Do they have engine oil in the crankcase and an oil filter, or do they just rely on crank bearings? 2. I know they have oil in the transmission, but do I use regular motor oil, or a special kind/brand? 3. Do they have a cam/valves (I dont think so :? )and how does the fuel enter the cylinder and the exhaust leave? 4. What is the best/most reliable oil to use in mixing the gas? 5. And, does the sparkplug ignite on every revolution? I know these ?'s sound pretty stupid to most of you 2-stroke diehards, but thanks for any answers.

-Kyle

[Jeb]

Wow, I always thought that 250R in your avatar was yours!

Answers:

2-cycle engines are much simpler than 4-cycle.

1) No oilfilters. No crankcase oil. It gets it's lubrication it needs from the oil mixed in the gas.

2) As far as tranny oil goes. you can use automotive oil. I've used 10-w30, but would rather use a good motorcycle gear oil. Some people have reported clutch slippage from synthetic automotive oils. I've never used any synthetic.

3) They do not have any valves or cams in the sense of a 4 cycle. Some 2 strokes do have a powervalve which, by various manufacturer dependent designs, alters the exhaust port height so the motor can be tuned for peak top-end power with sacrificing low end. Most MX-er's have had power-valved engines since the early 80s. The honda 250R atv motor does not have a powervalve unless it's been heavily modified. B-Series Tecate 3-Wheelers, The Tecate-4, and the later Quad Racer's I believe are the only two-stroke ATVs to ever have a powervalve.

4) Your best bet is any name brand synthetic 2 cycle racing oil. I use Bel-Ray.

5) Yes, the plug ignites on every revolution.

A great reference: www.macdizzy.com

Hope this helps!

[86350X]

Don't forget about reed valves on th intake side,, They prvent the fuel/air mixture from blowing back out the intake,,,, It would take a long time to explain how they work,, I recommend you do a search othe web I am sure you will find the principals of a 2-cycle engine somewhere

[FullBore]

Have a look at www.howstuffworks.com that tells you about every engine type.

Nat

[ATC crazy]

Sorry but I found the avatar on another site. :( Im just using it until I get my pics developed and run through a friends scanner. Thank you very much for all the help guys ;)

[als250]

273 posts ?? Must not have paid for "ONE HOUR" developing!!!!!!! :D(or maybe you just " FORGOT!! " ) lmao


Al

[Joel85350X]

Al, maybe he just TALKS A LOT.

:-P

Just kidding crazy.

[ATC crazy]

We have about 5 rolls of film from various things and I cant seem to find them. I had them for a while but we kept forgetting to take them w/ us when we go out and now they are gone again. I'll look for them and set them w/ my wallet.