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First Time Head Swap (Ski Doo 800r 07)

B
Dec 16, 2007
927
161
43
45
Mammoth Lakes, CA
www.pbase.com
I picked up a used trygstad head from fellow snowest'r Kuper! Thanks again for the prompt shipment great packing and top notch head, along with my clutch this weekend I decided it was time to swap the head. I've done a number of head swaps on cars, so I wasn't to worried about this task, for the most part it was straight forward but I'll go over a couple pitfalls, and unfortunately my blunder.


Here we are getting started, I popped off the plug wires, and after that removed the rave hoses and tucked them behind the frame
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I then removed the plugs, and the knock sensor, I put the bolt back in the knock sensor hole to minimize any coolant getting into the head.

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I then removed the heater hose from the carbs, I opened her up and drained the head from here this allowed me to control where the coolant went (to some extent). After this I removed the main heater hose mine was twisted so I couldn't get a screw driver in, I used a small racket with a 7mm socket to loosen up the clamp, I also undid the weather pack for the temp sensor.

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After that I removed all the head bolts, and popped off the head, before installing the new head, I dried everything off, and cleaned any coolant out of the head bolt holes. Unlike cars it appears these bolts don't pass threw water veins so you need to make sure to dry them out, or can damage your threads when you put the bolts back in.

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no more crosshatching, but not looking to bad, maybe It will be time to do a top end after this season
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Here is the new for me Trygstad billet head

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A side by side compression with stock, now here is 1 of my blunders, for some reason every thing on the head that needs sealing with the exception of the water neck on the underside of the head uses O rings.. I didn't have a replacement gasket in attempting to remove the stock gasket I did tear it some, but nothing a little High Temp RTV Gasket Maker won't fix (orange), although I do recommend replacing the gasket. I got lucky my RTV job doesn't leak but I do plan on ordering a new gasket just in case I need to change it out down the road. I then moved over the water temp gauge and the crab hose line, I sealed all brass fittings with Teflon paste.

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...now here is the unfortunate blunder I made. Hopefully this won't affect anything I'm going to need to send the photos off to trygstad but after taking the above photo I went to move the head and I spaced and forget the domes were removable.. yes. .you guessed it a dome slipped out bounced off my trailer and hit the floor, and put a couple small kink in the outer edge. I did the best I could to de-bur it so it will still seal but only time will tell if I need to replace the dome..depending on if I start blowing o-rings or not. (any suggestions or thoughts would be great)

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...sigh..
anyways there was no turning back. I wanted to get it together and fire it up to see if anything leaked, or If I could easily tell if that kink was going to be an issue. So after throwing a temper tantrum, and bloodying up my hand I started put the sled back together. I bolted down the head in a star pattern and torqued it down to 21 foot lbs

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After that I hooked the raves back up, the knock sensor and the upper coolant return torquing the knock sensor to 18, I then re-installed the spark plugs and wires (yes I need a new boot for that wire haha)

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and here is the finished job, makes me wish the whole motor was billet
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I re-installed my primary (hadn't put it back on from before), and fired her up. Wow she sounded great, also idled a fair bit higher, I adjusted my carb idle screw, and let her get to operating temp once at operating temp I inspected the sled for any coolant leaks so far so good.. so wish my luck hopefully that kink in the dome won't cause any issues if not.. look for the "dammit.. here we go again thread"

-Brahm
 
Last edited:
W

wazzusummit

New member
Nov 26, 2007
157
0
16
37
Kennewick, WA
Great post Brahm. Looks good. I am debating on a head swap as we speak. I cant decide just doing the head or doing the RKT drop in kit.
 
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