I bought my 2001 ski doo summit 800 without really looking at it it was 300 bucks, got it home and the carb boots were all cracked with silicone trying to seal them ugg. The carb had the same silicone for gaskets. Because of the cracks in the boot I'm guessing it over heated and got some scores on the bottom piston, the cylinder from the top looks near perfect still Has cross hatches. Feels like it has insane amounts of compression but will check tomorrow. Only has 1600 miles on it.
I have an 02 mxz 600 and it’s got over 10,000 on it and it still runs good.takes 5-8 pulls almost every time but my reeds and carb boots are beat up.but I plan on doing a rebuild this spring if she makes it this season
I ran that sled down to 89 in one cylinder and 90 in the other before i rebuilt it. That said after the rebuild with rk tech head they were pushing 165 in both. The only time that sled was not a first pull sled was when you drove it up on the trailer warm and drove down a bouncy road for 15 miles the combination of it getting bounced down the road and it seeing to cool down at the same time caused it to be the most stubborn sled to start ive ever seen barely able to get it to go with either! The conclusion that i was only able to come to is that it saw to cause of it to vapor lock in the fuel pump diaphram some how some way! The only other thing that i can see to warn about those sleds is if you ever find of yourself putting it under significant load when the ambient temp is a dank and warm 42+ degrees F out like breaking trail for like 5 min straight. To ones suprize when you let off the throttle it may indeed remained pinned due to them having seen to freezing solid no matter what you see to do! Warm water freezes faster than cold water so i can only assume the same proves true with fuel upon the flat slides of the 40TM carbs. In 2002 they added a circut of coolant that ran thru the carbs to prevent of it. It can see to be a real wake up call upon reaching the end of the snowed over road! The carbs are similar enough to get a pair of the 2002's and just swap over all your jets as the factory settings seemed to me to be far different as i believe 2002 they went to The H.O. by port raising of the exauhst ports freeing up about 20 h.p. in stock N.A. form. Good things to know. I still have that sled stock it weighed 499lbs it presently sits @ 389lbs When i get on any other zx I am quickly reminded as to what complete tanks they really were in stock trim. It is still a first pull sled that i rebuilt with the intentions of turboing it but it runs so darn good N.A. i just have not been able to force of myself to do it to it! Beside they come that way from the factory now if i want it turboed i can pretty much by one that way!
Sure thing. Here are the parts I used on this engine: - Pistons: $85 x 2 (www.ebay.com/itm/323207107130) - Wrist pin bearings: $12 x 2 (www.ebay.com/itm/265523900163) - Gasket set: $35 (www.ebay.com/itm/293106946123)
these links no longer work @@some-guys-garage I just purchased this exact same snowmobile and would like to do a top end rebuild can you put new links for parts please?
I got one I think the main problem is it's not getting enough fuel on startup. There is no primer unless I missed it but take off the plugs and pour some fuel in the cylinders and they or mine fires right up first go. Not that I want to do that all the time but it's not getting g fuel at start up
What scored the piston in the first place? something caused a lean condition on the intake side, if you don't solve that problem, it is very likely it will do it again in the near future. It could be sucking air from cracked carb boots or reeds, it could have bad gas in it, plugged jet, bad crank seal on that side or both sides. Oil injection system may not be working properly. I would be willing to bet its the 22 year old crank seals.
I would be willing to bet it's the 22 year old pistons. Although you are correct that a lean condition can cause premature failure, I would hardly call this failure premature. Pistons and rings eventually wear out even under perfect operating conditions.
Those are funny pistons then, they only wear on one side. I didn't call it a premature failure, things can fail at any time. I just don't want some kid to slap pistons in his machine and go 3 blocks and blow his engine again. You should do a leak down test after a rebuild but you knew that right, those 20 dollar crank seals would have blown your budget I suppose.
Thanks for the clarification. Glad you're here to police RUclips on behalf of the kids of world. Kids - before you run off and break your rebuild budget on $20 crank seals, take note that on this project the combustion pattern on the cylinder heads and spark plugs looks nearly identical between them with an edge toward incomplete combustion (not lean). Also note that the difference between the pistons was that one had a gouge in it directly in line with the ring gap, indicating a failed ring (or other debris) in that cylinder. Also, kids, always perform a leak-down test after a rebuild. Because I'm sure you have tools to do that. If you don't have a leak-down tester, give me a call. I have one that I used on this job. Crank seals are fine.
Happy to hear I'm helping my friendly neighborhood ancient snowmobile mechanic stay in business! And, yes, if you want to learn more about reading rich/lean condition from spark plugs, my 15 year old son would be happy to give you a primer course.
Oh, very good! I suspected the same thing for a minute, and even thought that might be the problem for a minute, but they're good. No cracks, no leaks.
@someguyzgarage yep the carb boots are the weak link on these sleds they tend to crack an last about 3 seasons. I ended up going with boyseen rage cages all aluminum they are the same price as v force 3s
Cringed when you hammered out the wrist pin....Dead blow or not, that is asking for trouble as you damage the big end bearing. piece of pvc pipe and a threaded rod is the way to pull it out.
I bought my 2001 ski doo summit 800 without really looking at it it was 300 bucks, got it home and the carb boots were all cracked with silicone trying to seal them ugg.
The carb had the same silicone for gaskets.
Because of the cracks in the boot I'm guessing it over heated and got some scores on the bottom piston, the cylinder from the top looks near perfect still Has cross hatches.
Feels like it has insane amounts of compression but will check tomorrow.
Only has 1600 miles on it.
I have an 02 mxz 600 and it’s got over 10,000 on it and it still runs good.takes 5-8 pulls almost every time but my reeds and carb boots are beat up.but I plan on doing a rebuild this spring if she makes it this season
Good luck. At least those old sleds are easy to rebuild. Thanks for tuning in.
Tbose ski doo 600s are the Toyotas of the snowmobile engine world. They are super reliable sleds an have more than enough power.
I ran that sled down to 89 in one cylinder and 90 in the other before i rebuilt it. That said after the rebuild with rk tech head they were pushing 165 in both. The only time that sled was not a first pull sled was when you drove it up on the trailer warm and drove down a bouncy road for 15 miles the combination of it getting bounced down the road and it seeing to cool down at the same time caused it to be the most stubborn sled to start ive ever seen barely able to get it to go with either! The conclusion that i was only able to come to is that it saw to cause of it to vapor lock in the fuel pump diaphram some how some way! The only other thing that i can see to warn about those sleds is if you ever find of yourself putting it under significant load when the ambient temp is a dank and warm 42+ degrees F out like breaking trail for like 5 min straight. To ones suprize when you let off the throttle it may indeed remained pinned due to them having seen to freezing solid no matter what you see to do! Warm water freezes faster than cold water so i can only assume the same proves true with fuel upon the flat slides of the 40TM carbs. In 2002 they added a circut of coolant that ran thru the carbs to prevent of it. It can see to be a real wake up call upon reaching the end of the snowed over road! The carbs are similar enough to get a pair of the 2002's and just swap over all your jets as the factory settings seemed to me to be far different as i believe 2002 they went to The H.O. by port raising of the exauhst ports freeing up about 20 h.p. in stock N.A. form. Good things to know. I still have that sled stock it weighed 499lbs it presently sits @ 389lbs When i get on any other zx I am quickly reminded as to what complete tanks they really were in stock trim. It is still a first pull sled that i rebuilt with the intentions of turboing it but it runs so darn good N.A. i just have not been able to force of myself to do it to it! Beside they come that way from the factory now if i want it turboed i can pretty much by one that way!
Well, that's a lot of info right there. You are clearly the master on that piece of machinery! Well done! And thanks for tuning in.
Could you post your parts list, pistons, bearings, seals, etc, and price of each? Nice video, I have a 2003 summit 800, that has similar problem.
Sure thing. Here are the parts I used on this engine:
- Pistons: $85 x 2 (www.ebay.com/itm/323207107130)
- Wrist pin bearings: $12 x 2 (www.ebay.com/itm/265523900163)
- Gasket set: $35 (www.ebay.com/itm/293106946123)
@@some-guys-garage Great thanks. for pistons at that price, might be easier than just getting new rings and trying to replace the existing ones.
If your pistons are good, you can just do rings. I did that on one of those two sleds. www.ebay.com/itm/233798716320
@@some-guys-garage Thanks. A guy told me the choke cable had too much play in it, so I will try that first.
these links no longer work @@some-guys-garage I just purchased this exact same snowmobile and would like to do a top end rebuild can you put new links for parts please?
Start to finish, without a trip or order parts. What kind of labor in time did it take? I have an ‘01 Summit 600 that’s a monster to start.
Probs 2 hours ish per engine.
They are pretty easy to work on an simple ski dod did a good job at making these sleds simple to work on an rebuild.
Sell those sleds in the UP of Michigan and they will be rebuilt and ripped around for another 10 years. 906💪
Thanks for tuning in. Yes, they are definitely better suited for the flat landers at this point.
@@some-guys-garage flatlanders? Aren't u God's gift to nobody who gives a shit about u
I got one I think the main problem is it's not getting enough fuel on startup.
There is no primer unless I missed it but take off the plugs and pour some fuel in the cylinders and they or mine fires right up first go. Not that I want to do that all the time but it's not getting g fuel at start up
What scored the piston in the first place? something caused a lean condition on the intake side, if you don't solve that problem, it is very likely it will do it again in the near future. It could be sucking air from cracked carb boots or reeds, it could have bad gas in it, plugged jet, bad crank seal on that side or both sides. Oil injection system may not be working properly. I would be willing to bet its the 22 year old crank seals.
I would be willing to bet it's the 22 year old pistons. Although you are correct that a lean condition can cause premature failure, I would hardly call this failure premature. Pistons and rings eventually wear out even under perfect operating conditions.
Those are funny pistons then, they only wear on one side. I didn't call it a premature failure, things can fail at any time. I just don't want some kid to slap pistons in his machine and go 3 blocks and blow his engine again. You should do a leak down test after a rebuild but you knew that right, those 20 dollar crank seals would have blown your budget I suppose.
Thanks for the clarification. Glad you're here to police RUclips on behalf of the kids of world.
Kids - before you run off and break your rebuild budget on $20 crank seals, take note that on this project the combustion pattern on the cylinder heads and spark plugs looks nearly identical between them with an edge toward incomplete combustion (not lean). Also note that the difference between the pistons was that one had a gouge in it directly in line with the ring gap, indicating a failed ring (or other debris) in that cylinder.
Also, kids, always perform a leak-down test after a rebuild. Because I'm sure you have tools to do that. If you don't have a leak-down tester, give me a call. I have one that I used on this job. Crank seals are fine.
Those cheap garage rebuilds keep me in business, great work. Burn patterns... too funny.
Happy to hear I'm helping my friendly neighborhood ancient snowmobile mechanic stay in business!
And, yes, if you want to learn more about reading rich/lean condition from spark plugs, my 15 year old son would be happy to give you a primer course.
Holy God! Paper Weights? What do you want for them? Apparently, I love Paper Weights.
Lol. Paperweights... if they don't start and the cost of the repair exceeds the value of the sled. They're great now!
How about the carb boots?
Oh, very good! I suspected the same thing for a minute, and even thought that might be the problem for a minute, but they're good. No cracks, no leaks.
@someguyzgarage yep the carb boots are the weak link on these sleds they tend to crack an last about 3 seasons. I ended up going with boyseen rage cages all aluminum they are the same price as v force 3s
I have been struggling to keep up with and complete all my projects. I just need to learn to make cherry pies.
Or apple, or rhubarb, or...
Wish you gerry and Mindy were my neighbors
Blushing. Thanks for the kind words!
Cringed when you hammered out the wrist pin....Dead blow or not, that is asking for trouble as you damage the big end bearing. piece of pvc pipe and a threaded rod is the way to pull it out.
Can't disagree with that. However, I'm willing to tap lightly. If they don't come, I use the puller. Never had a problem.
8:07 - I think moto moto likes you 🦛
Me moto moto.
I hate single ringers
Amen