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Discussion Starter · #1 ·
got my nice bottom end , got a new cometic .046mm base gasket, block was honed out .010 over as well as hot tanked, looks perfect, ordered up a set of .010 over parts unlimited pistons from dennis kirk, and the head gasket looks brand new from the previous so called rebuild. picking up the block tomorrow from the hone job, waiting for the piston kit to come in. so decided i would ask what steps i will need to take to insure the motor to work correctly or what not. so i have heard people talk about rings having to seat properly, what does this mean exactly? also what other things do i need to keep in mind before i put everything back together?

Now you are probably asking what application is this for? alright so i am using a 1990 indy trail (400) bottom, with my 98 indy 500 block/head .010+. was told that people have done this before and wont be a problem. Reason for the older 400 bottom is because i dont have the money as of right now to rebuild 500 crank, and got the 400 motor for dirt cheap and it is nice, tight, and quiet. thanks for any advice or help in advance!
 

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Google "Two Stroke Break In Procedure" and find all sorts of conflicting Info,
Everybody has a Better Idea... To eliminate Glazing and Blow-By
I suggest You Read Up and pick your poison.


I'm a 2500-3000 RPM Idle for 10 Minutes First Run Guy
2nd Run- Warm it up and Ride it, Don't let The RPM's stay the same.
Don't Rev the Crap out of it, Do alot of Throttle Blipping.
Gradually Ride it harder up to the 1st Hundered Miles
and then Call it "good to go".

The List is endless as far as "Tips and Tricks". Here are a few of My favorites.

Premix The gas in the Tank until you are certain the Oil pump is operating,
Make sure you bleed the Pump!
You can't get it Clean Enough.
Don't Reuse Old Circlips.
Torque All fasteners to Spec.
Don't use Silicone Gasket Crap.
Check your Hoses Since the Motor is out.
Bleed The air from the system by elevating the front of the Sled.
 

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Break it in hard or the rings will never seat properly. Now "hard" isn't defined as redlining it all the time. Load the engine out on the trail for a second or two by getting on the throttle, say hit half throttle from just above idle, and then back off, let the engine speed come down, rinse, repeat. Just running the engine at X rpms doesn't build up enough gas pressure in the cylinders to force the rings out against the cylinder walls and that's required for breakin. There's no magic to engine break-in. Avoid a constant speed (like idling) at all costs until the breakin is complete.
 

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i agree with ttyR2 i've rebuilt a few auto motors aswell as a old liquid yz125 bike aswell as a Nitro RC's and you need to load the rings by goosing the throttle for a sec. NO REDLINES STAY BELOW 1/2 THEN AFTER A BIT MOVE UP TO 3/4 then let it engine brake (slow on its own) until your almost stopped then like ttyr2 said rinse and repeat lol dont haul ass or ride hard do let it warm abit b4 this not long (idling bad LOL) also asemmble it with white grease (assembly lube) that way nothing is dry when you fire it up the first time. but like oldslednut said everybody has a way of doing it this is the most talked about one i have come accross and has worked well in all i have done big(550hp 351 boss) and small(Nitro RC) but dont forget the lube lol
 

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Discussion Starter · #5 ·
nice info guy's thanks a bunch, i am going to go skiing this weekend due to not getting parts back in time... so i will put her back together Monday and see how she does...
 

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How did your machinist get the proper piston to cylinder wall clearance with out the pistons?[/b]
he used the hone?! duh!
im hoping he meant bored, but yes, specially with wiseco, this measurement is critical.
beat it in. if its gonna break its gonna break, just no constant rpm
 

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he used the hone?! duh!
im hoping he meant bored, but yes, specially with wiseco, this measurement is critical.
beat it in. if its gonna break its gonna break, just no constant rpm[/b]
I'm thinking XSSKIER had a valid Point , Without the pistons in your hand to measure
it's only a guess at what size to make the F'in hole.
BTW- a Real machine shop will have honing machines to go oversize without making chips first..........
Wiseco pistons only need to be "Fit" differently than a cast piston.
 

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I'd do what some of the other members reccomended on here, let the sled idle for a minute or two when you first fire it up. Then shut it down, check your plugs for proper lubrication. I always, and i repeat always use alot of Klotz Assembly lube when assembling the top end incase you have an oil pump failure. After idling take it for a slow spin, and then go ride it for about an hour or two checking your plugs, coolant level, etc. Good luck.
 

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Discussion Starter · #10 ·
he used a bore gauge and gave me the diameter of the hole,its a reputable machine shop. he then told me i needed to get pistons that where 2.874 i think.. not sure dont have numbers in front of me i am in maine right now.
 

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Personally, I wouldn't use anything but 2 stroke oil to pre-lube the crank bearings, rod bearings, and such. I would imagine grease would take a while to clean out once the engine is running before the oil mist in the air/fuel would be able to get to the bearings. On a 4 stroke engine, you have a pressure lube system to flush the grease out and get oil flowing, you don't have that on a 2 stroke engine. 2 strokes burn everything in the cylinder/block whereas 4 strokes only burn stuff in the combustion chamber (not including the slight amount of oil that makes it by the rings and valve seals), and grease doesn't burn very well.
 
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