Need advice on rebuild

[2.S.F.L]

Hey everyone, i dont know what to do. My sled is a 2005 rev 800 with 3500km without a problem so far, i bought the sled with about 2500 km and the last 1000 have been pinned to the bar. so im really thinking about rebuilding it befor she blows, im 16 years old and on a tight buget. i have been thinking about the rkt drop in kit because i would like to get a little extra hp out of it but dont want to miss out on riding because i have to get my MPEM re-curved and heard that it takes awile. or should i go with the stock pistons and rebuild it. i would like to rebuild it myself to save some cash but i have never rebuild a sled befor so im worried i will mess something up. i have torn apart chansaws,weedwackers and lawnmowers right down to the pistons and put it all back together and ran fine afterwords, im kind of a mod freak i love modding things up, you should see some of my chainsaws, custome exhaust, little port and polish and custome intake hahahahhaha. so im fairly mechanicaly inclined, my dad is a heavyduity welder and my brother is a heavyduity mechanic so it kind of runs in the family. i really hope someone took the time to read all of this, i would really apprecate any help because i dont knwo what to do. sorry my spelling isnt the best but i really tryed.
Thanks, Travis

 

[Spaarky]

IMO, if your gonna bore, go with a kit from Big John(he is on the forum). Rebuilding the motor isnt that tough, but there is some key things if you miss you are screwed.

Personally I would try to find someone who knows exactly what they are doing and have them help or have a mech. do it. Your budget is tight, you dont have a lot of room for error.

 

[G-Force]

Bah, sled engines pretty basic, just remember righty-tighty, lefty-loosey. Just ask whatever dealer you get your parts from (even better if it's your Doo dealer) for the torque specs and pattern on the jugs/head, and you're golden. Just remember where everything you took apart went and you'll be fine. Shoot, snap some pics with the digi-cam for reference. When I used SPI pistons to rebuild mine, the sheets that come with tell you what to do so far as lining up the ring locator etc and which way faces forward so, take yer time and you'll be fine.

 

[markoo]

At 3500 km's I wouldn't touch it. You should be good for another 3500.

 

[2.S.F.L]

ya i think i will do it myslelf really hope i dont screw anything up sould i get a manual on how to do it or dont bother, but ya good idea with taking some pics to rember how everything whent back together. i think ill go with spi pistons how are they? my dad just put them in his sled a couple weeks ago but done by the dealer and seems to run be running strong so far. another 3500km?? i duno im already loosen big time compresion, so i think ill do it now befor she goes boom and does even more damage i cant afford, and some spots we get our selfs into if something were to go rong would have to get a heli ride out.

 

[Tackbtch]

I say go for it yourself, if you get into a bind theres lots of good peeps on this site that will help ya out. If you doo the rebuild I would repack the pto bearings with grease...not that tough to doo. I installed new bearings on my 02 this year. As stated above...find a doo dealer , get some info , maybe a few pics from a manual. Shouldent be a problem if you have torn down small engines ...kinda, I say KINDA the same thing. Take your time. Dino

 

[Mafesto]

One obvious warning.
Be carefull with the cageless needle bearings.
Count them and recount them so you are confident none are missing in action!

Give your local Doo guy a gift certificate for a nice meal somewhere & perhaps he will allow you to borrow a manual & special tools.

 

[2.S.F.L]

Tackbtch like you sayed to repack the pto bearings with grease, i was thinking about while i have them out why not just replace them to ba safe.

Mafesto One obvious warning.
Be carefull with the cageless needle bearings. were are the cageless needle bearings? sorry probally a dumb question but i dont know. and also what special tools will i need?

Thanks for all the help guys.

 

[JROD]

There are 28 needle bearings used for the upper rod bearings that are cageless, meaning they will fall out as soon as you pull your wrist pin. MAKE SURE YOU COUNT ALL OF THEM SO YOU KNOW FOR SURE THAT YOU HAVEN'T DROPPED ONE IN YOUR CASE!!! It happens.

A wristpin puller comes in handy so as not to damage your connecting rod. They're pretty cheap and worth their weight in gold. http://www.hiperf.com/acatalog/Snowmobile_Catalog_Shop_Tools_45.html

Also make sure you check your ring end gap and set it to about 24/1000s on the top ring and 22/1000s for the lower ring if applicable.

If you can get your cylinders honed that would be smart as well.

It's really not a difficult procedure and if you're mechanically inclined you shouldn't have a problem. I'm 23 now and have been building engines and sleds for a number of years. Don't let anyone tell ya you're too inexperienced. I've heard plenty of that BS.

 

[2.S.F.L]

is it tough to get the needle bearings out without dropping any?? is there any tricks to get them out without dropping any?.

thanks alot for that site will have to look into getting a couple tools off there. and you also sayed might be a smart thing to get my cylinders honed also is this something i can do myslelf i seen the tool on that site.

Thanks alot for the advice i really wanna learn how to do it. does anyone know of a good maunal to go by when doing this??

 

[JROD]

You can get them out with a magnet if you had to or a little grease on the end of a screwdriver will usually grab it. Just try to cover everything with rags while you're taking them out then put the connecting rod between your middle and ring finger. You'll catch most of them that way.

You can hone it yourself but don't use a ball hone on those cylinders. Use a brush type or rigid hone

Torque cylinder bolts to 30 lbs/ft
Head bolts to 21 lbs/ft
Exhaust Valves to 80 lbs/in (THATS INCH POUNDS) Not as critical but you get the idea

Exhaust manifold bolts to 89 lbs/in ***Doesn't hurt to put a little red loctite on these
Carb boot bolts to 49 lbs/in***

 

[2.S.F.L]

thanks for all the advice jrod

sounds really tricky to get them cagless bearings out but i think i will really take my time with it. still a little nerves about doing it all myslelf but im pretty shur i can do it. another question i have is how do i get the jugs off it looks like they will hit on the frame when i pull them up?? do i have to remove this frame or will i be able to squeez by?

 

[2.S.F.L]

SledPro Moly Piston Kits has anyone ever tryed theys pistons?? and if so what kind of luck did you see?

 

[Weekday Warrior]

if your loosing compression ya get er done!

I woulda suggest leave it until summer otherwise.


snap lotsa pics and post em up, specially tear down pics and good close ups of pistons, cylender walls & heads

 

[2.S.F.L]

o ya ill be taken lots.

 

[PCDOC]

The cageless needle bearings aren't that tough to remove. As stated, just make sure you have a towel underneath the piston and wrap it around the connecting rod so if you drop one it won't fall into the case. I have always used a magnet while removing them to catch the bearings. That makes it quite simple. If you plan on replacing the crank bearings then is doesn't matter since you will have to open the case anyway. Replacing the pto crank bearing can be a tough task. You need a puller to remove the old one and to reinstall you have to heat the new bearing in some oil. I used and old electric skillet with motor oil. While the new bearing is hot you have to slide it on the crank and make sure it is in the correct spot before it cools (shrinks) onto the shaft. I had about 5 seconds to get it in position and then it was solid. Where do you live? I'm sure somebody close to you would be willing to lend an experienced hand.

 

[Tackbtch]

Tackbtch like you sayed to repack the pto bearings with grease, i was thinking about while i have them out why not just replace them to ba safe.

Mafesto One obvious warning.
Be carefull with the cageless needle bearings. were are the cageless needle bearings? sorry probally a dumb question but i dont know. and also what special tools will i need?

Thanks for all the help guys.

Ya you can replace the bearings if you want. If the bearings still have grease in them I would think they would be fine...mine were dry...$55 frogskins a piece from Doo. Might be able to get the same bearings cheaper from a bearing outlet??? Also get a complete engine gasket kit from Doo, Please dont try to save money by going after market there, you will hate yourself if you doo. LOL Youll be fine , its not that tough and good advise about the cageless needle bearings above. You can replace them with caged bearings ... I cant find my part # but sure some one can chime in. Dino

 

[2.S.F.L]

im not going to be replacing the crank bearings but thanks anyway. ya i think ill use a magnet to take them cagless bearings out, but like Tackbtch sayed i can get some caged berings that would be helpfull for putting it back together and next time i do it. i think the spi piston kit comes with complete gasket kit dosnt it? and if so are they alright to use?. PCDOC i live in Cranbrook B.c, would be very helpfull it someone could give me hand

 

[2.S.F.L]

well today was the day, she blew on me didnt even get out of the parking lot.....any ideas on what happened???