Siezed 800 Engine (Rebuild Advice Please) pics

0

001Ronin

Free Member

Oct 19, 2010

6

1

3

• Oct 19, 2010

• #1

I lost the Engine on my 2002 Summit 800 last year on my only trip out. I am just getting to the rebuild in anticipation of this years snow. I've had the sled for about 3 years now. Just need a little advice from those who have done this rebuild before. I am assuming that I will have to hone the cylinders and add all new pistons, rings etc...

Wondering if by looking at the picture you can tell me exactly what happened. In the left cylinder you can see shards of aluminium everywhere. The right Cylinder looks like its just been burned to a crisp. I did find a big tear in the rubber attachment to the right cylinder between the carb. That probably wasn't helpful.

Anyway, just looking to start a conversation here about it so I make sure to do the repair correctly. Thanks in advance for all your help.

 

Snow Duck

The Great and Mighty SnowDuck

Staff member

Lifetime Membership

Aug 27, 2009

3,367

1,383

113

Kuna Idaho to Elk City Idaho..

• Oct 19, 2010

• #2

looks lean to me

Look's to have leaned out in that side...i would clean and check jets in the carbs...mine did the same thing 2 year ago because of a plugged jet and my boots were cracked also so i went with boyesen reed set..
and yes a hone job with a new set of pistons should do the trick...
but i would recommend pulling the case and re-greasing the pto bearing if you have a fair amount of miles on it....

 

Last edited: Oct 19, 2010

C

cruiser76

Free Member

Jan 14, 2009

11

0

1

• Oct 19, 2010

• #3

Interesting pics...

what part of the piston went south?... the skirt?
those shards and parts are non magnetic so did the skirt give way and come up thru the intake and exhaust on the exhaust stroke?

is there a build up video or links where forum members have rebuilt their motor?
What part vendors do you guys use?

I see on ebay for top end kits for $299 ...Wiesco was always a good choice in my motocross days...

all opinions appreciated and will help the op.


thanks great thread

 

Last edited: Oct 19, 2010

R

Redsledhead

Free Member

Jun 14, 2008

651

39

28

Southern Idaho

• Oct 19, 2010

• #4

Have you checked the cyclinder walls for any scaring? make sure no scratches in the cyclinder. Also when you take piston make sure and have a towel or rags covering up the case below the piston as the needle bearing will fall out. I have installed new SPI pistons with good luck. Miles on motor will be a factor on what you need to do.
As for the piston boot cracks cause lean troubles, what octane gas wrere you using?

 

0

001Ronin

Free Member

Oct 19, 2010

6

1

3

• Oct 19, 2010

• #5

I haven't lifted the head off the case yet so I have only seen the cylinder walls above the piston. They looks to be ok without too bad of scarring. I think I have worse problems down below so digging deeper will tell what I have to do down below. Local shop quoted me $125 per cylinder for the top end kit. They cautioned against honing the cylinders because of they are coated with a special material. You can't just bore out scars in the cylinder. If the scarring is too bad he said a machine shop will have to weld in a sleeve and bore that.:face-icon-small-con (oh, yeah... I always run premium pump gas, usually 87-89.)

 

Snow Duck

The Great and Mighty SnowDuck

Staff member

Lifetime Membership

Aug 27, 2009

3,367

1,383

113

Kuna Idaho to Elk City Idaho..

• Oct 19, 2010

• #6

Redsledhead said:

Have you checked the cyclinder walls for any scaring? make sure no scratches in the cyclinder. Also when you take piston make sure and have a towel or rags covering up the case below the piston as the needle bearing will fall out. I have installed new SPI pistons with good luck. Miles on motor will be a factor on what you need to do.
As for the piston boot cracks cause lean troubles, what octane gas wrere you using?

Click to expand...

im with Red on this spi pistons....make sure to get the caged bearing's...the cyls can be light honed but if more is needed you will have to send off to renick the cyl's....

 

R

Redsledhead

Free Member

Jun 14, 2008

651

39

28

Southern Idaho

• Oct 19, 2010

• #7

I agree with Duck a light hone is ok but any scaring on the cyclinder walls need to have them re nickled. I would never sleve have heard bad things about it . Any holes in bottom case ? Be sure and check

 

M

Modedmach1

Well-known member

Nov 26, 2007

508

109

43

Fairbanks, Alaska

• Oct 19, 2010

• #8

SPI pistons are good, I have used them in several motors. Wiseco's are good as well but, you have to be careful, they cold seize easy. You can lightly hone the cylinders but, if they are scratched very deep trade them in on re chromed ones. Put a couple rags around the rod & over the holes in the case when pulling the wrist pin bearings. They are not caged & will go every where, you can put a strong magnet under the piston & catch most of the needles. Go back together with caged bearings. V force or boyesen reeds work well & solve the delamenation problem with the stock reeds. If there is any metal in the case, take it apart, clean it & regrease the PTO bearing. My .02

 

J

JustinB

Well-known member

Dec 21, 2008

1,691

645

113

84050

• Oct 19, 2010

• #9

Check out my pics in my 02 rebuild on this section I went with the MCB duel ring piston kit great guys and the most stuff for your money. Comes with the caged wrist pins. Be careful getting the uncaged pistons out with out dropping them into the case. Good luck

 

0

001Ronin

Free Member

Oct 19, 2010

6

1

3

• Oct 20, 2010

• #10

Thanks for all your input Fellas:yo:. That is exactly the info I was after. I will update the thread with more progress.