Final got my R up and running. Only took 3 kicks! and it started right up. Thats what I call reliable honda [img]i/expressions/face-icon-small-smile.gif[/img] hasn't been started in over 8 years! runs awesome!

 

im feeling you on that one .... kicked mine over for the first time in a few years... theres nothing like the smell of 2-stroke exhuast.. just a few minor bolts and teh the first part of teh rebuild is done

 

Hey elsancho, Whats up. The first ten mins after it started up it was smokin like crazy! I could barly see anything for a few mins!. This is my first clutch quad and i have to say it was very easy! People make it seem like it so hard. and what are people talkin abotu the 250r clutch bieing very rough. it was very smooth with me. performance mods so far include: Uni filter, larger carb, ngk spark plug. runnin belray tranny fluid too. i might need to top of the coolant and or the break fluid.

later

 

Robert you may want to inspect the plug after a wideopen throttle chop to see if she is running lean or rich.
the trick with two srokes is checking up on certain things.

You may as well run a compression test on it and post the results. a 250r should be around 160 - 170 psi (after 20 or so kicks with the tester in the spark plug hole. if its any less think about doing the top end immediately.

It sounds like it might need a top end since you said it smokes alot, the rings could be worn out.(or its running really rich, that would show a black or brown colored sparkplug)

If you do buy a top end dont buy a forged piston, use a cast piston like a mix pro x or a honda (the company art makes both nix pro x piston and factory honda pistons so they are both high quality) forged weisco pistons or the like, arent to good with a 2 stroke motor.
see, cast pistons expand and contract faster than a forged piston does. because of this fact, when a cylinder is dropping in operating temperature because the rpms arent up as much, the cylinder contracts at a faster rate than a forged piston thus wearing the piston rings out quicker because the piston is still expanded because of its metal characteristic.(you can cold seize a motor easily with a forged piston.

make sure you check this stuff out.

Alot of people dont bother checking the motor and end up blowing it up and replacing more than the top end because of not checking up!

what ratio are you running?

I would recomend 32:1 maxima castor 927, you could buy it on line in half gallon containers for 16 bux!

 

<< see, cast pistons expand and contract faster than a forged piston does. because of this fact, when a cylinder is dropping in operating temperature because the rpms arent up as much, the cylinder contracts at a faster rate than a forged piston thus wearing the piston rings out quicker because the piston is still expanded because of its metal characteristic.(you can cold seize a motor easily with a forged piston. >>




Forged pistons expand more than cast. Pro-X and ART are cast!
ERIC

 

Hey, I'll tell you what. .I ran a Weisco piston for a long time. Years. No problems. You just let it warm up good before you go nailing the throttle.
Smoking a lot doesn't necessarily mean you need a top end job! First, do the plug check and make sure it's jetted correctly. Next, check the fuel/oil mix you're using (I hope it isn't Hondalube @ 20:1!!!). I use Amsoil 2000 @ 50:1. Readily available and reliable and lubes well, blah, blah, blah. Now my R smokes a bit, but I like it to smoke; I know it's not running lean then, and I'm too freaking lazy to change jets very often!!

 

forged pistons are also must stronger than cast pistons. That in itself is a good enough reason for me to run one. When you properly warm up an engine, you will not have any problems seizing an engine. 'Cold seizing' an engine, as beerock puts it, is from not warming up the engine enough before rodding on it.

 

Regardless if a forged piston is stronger the fact still remains that it expands and contracts at a slower rate than a cast piston.

the forged piston is always &quot;catching up&quot; to the cylinder expansion or contraction.
the cast pistons are in unison with the cylinder, which leads to longer life if maintained properly.

It is factual that a forged pistons rings wear quicker than a cast in 2 strokes.(because of the &quot;Catching up&quot; of the expansion and contraction. )

2 strokes are different animals than a 4 stroke, forged pistons are great for 4 strokes because the clearances can be less and 4 strokes dont expand and contract like a two stroke.

trapper, I did say do some checks first.



You may as well run a compression test on it and post the results. a 250r should be around 160 - 170 psi (after 20 or so kicks with the tester in the spark plug hole. if its any less think about doing the top end immediately.

just wanted to reitterate that, as to show that I didnt tell him to jump on getting a top end done.

isnt it just a classic scenario of someone buying a two stroke and having the top end blow on them, turning the owner into a brand hater or 2 stroke hater?
id rather inform a new 2 stroker to the possibilities of this then just letting it happen to him.

the piston choice in the long run is up to him.

AFter someone told me about the forged/cast expansion contraction scenario, I only get cast for my two stroke

 

Cast pistons do not 'keep up' with the cylinder. The piston is still aluminum, and the liner is still cast iron (in this application anyways). If the rings wear a little faster, I've never noticed it, and a good 2 stroke maintenance should involve at least re-ringing every year anyways. The difference is negligible.

The expansion in a 2 stroke and a 4 stroke are no different. Contraction occurs from heat, not from engine type. A 4 stroke application such as a 400ex actually expands and contracts MORE as it is air cooled where the R is liquid cooled.

So, like I said before, the difference is negligible, and if this is a problem, the same thing would occur in a 2 stroke, 4 stroke, 3 stroke, 19 stroke, it doesn't matter. Expansion and contraction of pistons occurs from heat, and heat alone.

 

Your right dill the expansion and contraction are the same but the RATE at which the pistons expand and contract is different
in a 2 stroke.

a 2 stroke is a different beast, the 2stroke heats up and cools (expands and contracts)down alot faster than a fourstroke while it is running. a four stroke stays within a certain operating temperature unless pushed hard, the operating temperature of a 4 stroke gradually goes up. A 2 stroke heats up ALOT faster, think of the rpms a 2stroke can turn compared to a four stroke, this proves the rate of heat is faster in a 2stroke.

the cylinders do expand and contract and I will add that the 4 strokes dont expand and contract nearly as much as a 2 stroke. this is why the clearances on a 4 strokes piston to wall clearance is alot tighter than a 2 stroke. for this reason, if a 4 stroke expanded and contracted like a 2 stroke the rings would wear ALOT faster and would probably burn oil.

four strokes do not expand and contract as much as a 2 stroke does, or as often as a two stroke does, thats why it is nessecary to rebuild the top ends every 30 hours or so. If a four stroke expanded and contracted like a 2 stroke then they would need top end rebuilt too.

why do you think the piston to wall clearances are tighter on a 4 stroke?

&quot;good to stroke maintenence involves re ringing every year?&quot;
WHAT? you must not ride much.

I put a new piston and ring, wrist pin bearing, wristpin, and circlips every 20-30 hours.