07 600rmk compression

[DUSTINSPELLMAN]

both are 100-105 is this good for a 2007 600 rmk? shouldnt it be around 140-150

thx

 

[maxwell]

should be around 140-155 like you said. especially for a 2007. depending on miles of course.

take your cylinders into cycle works in edmonton. great machine shop there. they will have your cylinders bored and new pistons and gaskets for 500-600.

but do it soon before winter!!

 

[ZRrrr]

140-155...wow, decent compression on a 600.

 

[maxwell]

140-155...wow, decent compression on a 600.

ive rebuilt tons of doo 600s. and 155 is the norm after a proper machineing and new pistons and rings.


if i see less than 150 on my 600 sleds i get worried.

maybe 155 is steep i dont know? but 105 is way to low.


but lets not forget about how you tested it either.

was it warm? throttle wide open? ive found when people dont run there machines for a couple months and just to a compresssion test without proper oil circulation and whatnot the compression tends to be on the low side.

 

[Modman]

Most are 135-140 new, likely due to different readings between compression testers probably. Actual 155 psi, consistent running and you would likely be starting to run race fuel or detonating on pump gas. Once the rings seat, the compression will drop a little. The 600's could be a little though, since the manufacturers are asking them to make so much power these days, they might be a little higher compression to get that little bit more power. I don't play with the 600's all that much but the one I did last year was 135 both sides and it ran amazing all year til it broke a ring and needed a new one. Two new pistons and rings and it was good to go. Starts second pull every time.

Anything less than 115 and you should be worried, most motors are fine at 120-150 IMO.

Shouldn't need a bore job for that 600 to bring compression back, need to measure slugs and figure out if piston/rings are worn, then measure for out of round on cylinder, then measure deck. Probably will just need new pistons and rings with a light honing. If you overbore you will have to have the cylinders re-plated.

 

[ZRrrr]

All good points gentlemen.

 

[DUSTINSPELLMAN]

ive rebuilt tons of doo 600s. and 155 is the norm after a proper machineing and new pistons and rings.


if i see less than 150 on my 600 sleds i get worried.

maybe 155 is steep i dont know? but 105 is way to low.


but lets not forget about how you tested it either.

was it warm? throttle wide open? ive found when people dont run there machines for a couple months and just to a compresssion test without proper oil circulation and whatnot the compression tends to be on the low side.

used a MAC TOOLS compression tester (should be real accurate) but no it wasnt warm. throttle was wide open. but we should have warmed it up first didnt think that through lol. This is not my sled again, posting for a friend. we will have to warm it up and check again but 100psi is very low even for a sled that has been sitting for a while>IMO

there is about 3800miles on it, should be due for a top end. but ill double check

 

[Modman]

used a MAC TOOLS compression tester (should be real accurate) but no it wasnt warm. throttle was wide open. but we should have warmed it up first didnt think that through lol. This is not my sled again, posting for a friend. we will have to warm it up and check again but 100psi is very low even for a sled that has been sitting for a while>IMO

there is about 3800miles on it, should be due for a top end. but ill double check

It will change with heat for sure, no point doing a cold compression test. Don't forget to keep the key off and kill switch off and tether cord out when you pull it over, or you can possibly hurt the ignition system.

 

[maxwell]

i wasnt telling him to overbore. just saying let the machine shop decide whether it be a hone or a bore. buying a set of oem pistons and slapping them back in is the WRONG way to go about this. haha but you knew that.

either way 3800 miles thats a deecent life im not suprised.

 

[Modman]

i wasnt telling him to overbore. just saying let the machine shop decide whether it be a hone or a bore. buying a set of oem pistons and slapping them back in is the WRONG way to go about this. haha but you knew that.

either way 3800 miles thats a deecent life im not suprised.

Your first post talks about boring out, which led me to assume that you were talking about boring out...."take your cylinders into cycle works in edmonton. great machine shop there. they will have your cylinders bored and new pistons and gaskets for 500-600".

Why is putting new OEM pistons in the wrong way? If the cylinders are within tolerance and are not out of round and have no marks or scratches, I see no reason to spend more money than required. Why overbore and start creating issues on a great motor? If you bore out then you will need to have them re-nik'd, depending on how big you go, more work will be required, all of which will be far more than $500 (closer to $1000 at the cheapest). A full top end kit and a full gasket set will run you at about $500 for that motor alone, unless you go with Wiseco's which will save you some $$$. There is obviously a lot more I would do to that motor as well (crank run out etc) with 3800 miles on it, but if it all checks out, then new top end and a light honing is all I would do (honestly I would consider throwing a new crank in there as well while it is tore down, I doubt it will be near perfect spec).

I'm curious as to what you would do differently apart from new slugs, rings, bearings and a light honing? Just trying to get a feel for different ideas.

 

[maxwell]

thats all i would do if thats all it needed. i wouldnt overbore it if it was required. im just saying if your not experienced with checking motor tolerances and deciding whether a cylinder is good or bad let the machine shop check it out and either bore hone and replace with oem or wiseco whichever is up to you. yaaaa know

 

[Modman]

thats all i would do if thats all it needed. i wouldnt overbore it if it was required. im just saying if your not experienced with checking motor tolerances and deciding whether a cylinder is good or bad let the machine shop check it out and either bore hone and replace with oem or wiseco whichever is up to you. yaaaa know

10-4. I get what you're saying.

 

[DUSTINSPELLMAN]

still havent rechecked but if were going the rebuild way, im going to install a 660cc or 727cc kit from slp to get more power
ive heard the kits work unreal in the sled and 150 hp from 120 is a night and day difference

 

[maxwell]

cool. is that carls cycle makes the 660? are they both 150hp? ive heard good things about the 660.

 

[DUSTINSPELLMAN]

cool. is that carls cycle makes the 660? are they both 150hp? ive heard good things about the 660.

no its slp
the 660 claims 138+hp
and the 727 claims 150Hp

 

[snwrdr4life]

Carl's is a better setup, they have a full package with the porting and everything, their kit works really well, and has everything down to the clutching.

 

[DUSTINSPELLMAN]

YAH i checked tha carls ones they look good to and lots of ppl on snowest says there prety good