Jump to content

2008 Polaris 700 cfi rebuild


Recommended Posts

Not my dragon but I will be rebuilding the other dragon rmk I bought that had a piston ring catch the exhaust port. 

I found a guy that has a whole engine out of a 2007 700 rmk. Says the bottom end is toast due to "dry sieze". Says the cylinders and head are good. Everything for $80. He is just trying to off load everything 

Is it as simple of deglazing the cylinders, fresh set of pistons and go? Is there any reason that won't work? 

Ps. I know I will need gaskets and such

Link to comment
Share on other sites

So it looks like the ‘07 and Early Production ‘08 700 motors used the same cylinder. It is Polaris Part # 3021767. It looks like they share the same head too. 

I will keep digging and see what I can find on the late production 2008 700 motor. 

Link to comment
Share on other sites

The Late Production 2008 700 motor uses a different cylinder, different throttle body and different fuel rail. 

The ‘07 700 motor shares the same crankcase, head, injectors, base gasket, exhaust valves and many other parts with the ‘08-‘10 700 motor. 

The 07 motor uses unique pistons  

So i cant offer a definite answer but it looks to me like the late production 08 cylinder will work on your ‘07 motor.  

 

Link to comment
Share on other sites

1 minute ago, AKIQPilot said:

The Late Production 2008 700 motor uses a different cylinder, different throttle body and different fuel rail. 

The ‘07 700 motor shares the same crankcase, head, injectors, base gasket, exhaust valves and many other parts with the ‘08-‘10 700 motor. 

The 07 motor uses unique pistons  

So i cant offer a definite answer but it looks to me like the late production 08 cylinder will work on your ‘07 motor.  

 

Ok. So if my 08 is an ep08, then zero issue. 

If it is a lp08 then different cylinder, pistons, TB, fuel rail. 

I wonder if i do have a LP 08 if I could use the 07 cylinders and just use that style piston. And get the tb and fuel rail to match?

 

Link to comment
Share on other sites

After talking to you, I remembered babbits parts. So it would appear that 07 and early production 08 use a two ring piston where the late production uses a single ring piston. 

Went through some pictures of when I got the sled in September and....

 

These look like 2 ring pistons to me lol. 

That 07 engine should be the ticket.

received_407930493257801.jpeg

Link to comment
Share on other sites

9 minutes ago, Tomas. said:

Ok. So if my 08 is an ep08, then zero issue. 

If it is a lp08 then different cylinder, pistons, TB, fuel rail. 

I wonder if i do have a LP 08 if I could use the 07 cylinders and just use that style piston. And get the tb and fuel rail to match?

 

I think the fuel rail will fit either cylinder. I think there is a slightly different mechanism in the LP 08 cylinder to retain the fuel rail. 

How much for the motor with the bad crank?  Seems if you can get that complete motor for a reasonable price you can use all the top end parts on your cases. 

I never owned a 700 so I cant be 100% sure the parts will interchange but the fact that the cases and guillotines are the same tells me the cylinders will interchange. 

Link to comment
Share on other sites

2 minutes ago, AKIQPilot said:

Well if the bad motor has good cylinders that is a no brainer then for $80cad. 

That's what I was thinking. He is desperate to get rid of everything. Offered me the track, rails, straight tunnel for $80 each, hood for $40. 

Claims he needs to make space and wants it all gone. Everything is already stripped and ready to take home.

Edited by Tomas.
Link to comment
Share on other sites

20 minutes ago, AKIQPilot said:

Yes. They went from dual ring to single ring pistons during that time. 

Kind of off topic but what would be the benefits of a single ring vs. a dual?

Link to comment
Share on other sites

14 minutes ago, Tomas. said:

Kind of off topic but what would be the benefits of a single ring vs. a dual?

If you have time google Rich Dailey single ring VS double he explains it.

Link to comment
Share on other sites

55 minutes ago, AKIQPilot said:

The Late Production 2008 700 motor uses a different cylinder, different throttle body and different fuel rail. 

The ‘07 700 motor shares the same crankcase, head, injectors, base gasket, exhaust valves and many other parts with the ‘08-‘10 700 motor. 

The 07 motor uses unique pistons  

So i cant offer a definite answer but it looks to me like the late production 08 cylinder will work on your ‘07 motor.  

 

I remember people were getting pissed with their 08 poo 700 snow check orders because they got it very late  and I mean like last week of December 

Link to comment
Share on other sites

9 hours ago, Tomas. said:

Not my dragon but I will be rebuilding the other dragon rmk I bought that had a piston ring catch the exhaust port. 

I found a guy that has a whole engine out of a 2007 700 rmk. Says the bottom end is toast due to "dry sieze". Says the cylinders and head are good. Everything for $80. He is just trying to off load everything 

Is it as simple of deglazing the cylinders, fresh set of pistons and go? Is there any reason that won't work? 

Ps. I know I will need gaskets and such

WTF is dry seize? If the crank "seized" from no oil the cylinders are likely junk. I have a 08 700. 2 ring pistons. I wasn't aware there was a early and late production difference. Ive never heard of the 700 ever having single rings. BTW I wouldn't want single rings for something that Im not tearing apart regularly.

 

BTW a stator bolt backed out of my 700 once. Stopped the engine like it was seized.

Edited by Legend
Link to comment
Share on other sites

28 minutes ago, Legend said:

WTF is dry seize? If the crank "seized" from no oil the cylinders are likely junk. I have a 08 700. 2 ring pistons. I wasn't aware there was a early and late production difference. Ive never heard of the 700 ever having single rings. BTW I wouldn't want single rings for something that Im not tearing apart regularly.

 

BTW a stator bolt backed out of my 700 once. Stopped the engine like it was seized.

That's what buddy called it lmao. Definitely ran out of oil. One cylinder was good but unfortunately it is the wrong one. 

Upside is buddy wanted to get rid of as much as he could so I got a rolling chassis, 2009 dragon console, Polaris Jerry can rack, mint lightweight rmk seat, all can, chain case and some other bits and pieces for $150 and he delivered it tonight as he wanted the room lmao.

Link to comment
Share on other sites

I have a question, hopefully someone can answer for me.

So my 08 rmk has dual ring pistons which are early production.

The cylinders that are on it are late production numbers and should be for single ring pistons (that I know of looking at a parts breakdown)

Would that mismatch have caused the piston ring to catch the port in the first place? Or is that irrelevant?

Link to comment
Share on other sites

59 minutes ago, Tomas. said:

I have a question, hopefully someone can answer for me.

So my 08 rmk has dual ring pistons which are early production.

The cylinders that are on it are late production numbers and should be for single ring pistons (that I know of looking at a parts breakdown)

Would that mismatch have caused the piston ring to catch the port in the first place? Or is that irrelevant?

I think that is very unlikely. The port configuration would have to be different between the cylinders. And that changes all kinds of things for the engine. 

I won't say no fuckin way, but I really doubt it. 

What is way more likely is someone didn't set the ring gap.

Link to comment
Share on other sites

I agree with Legend. The ring end gap needs to land perfectly in between the ports. I also agree that rings need to be checked to ensure the end gap is within spec but rarely do you need to size a 2 stroke piston ring these days. 

A common problem with the first run of single ring pistons was if you ran them lean the detonation would knock out the ring locator pin and the motor instantly went south. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Trying to pay the bills, lol

×
×
  • Create New...