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Discussion Starter · #1 ·
Hey I'm looking to see if anyone has done a full rebuild on there p-tec 800r and used the kit that MCB sells ? I'm worried about the crank more then anything .....
 

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I have done a full rebuild of the 800R, but at the time it wasn't with MCB. However I have done multiple rebuilds on the most precarious Ski-Doo 2S with MCB crankshafts which were flawless. MCB is second to none. FYI, Ski-Doo is their specialty.

If you want proper compression, not that 130 psi BS, make sure to get new cylinders that have been trued and replated. The amount of compression that I get out of an 800R at sea level would blow your mind. 130 psi is in the wrong zip code.
 

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Discussion Starter · #3 ·
Daag44 thanks for the info I'll order a new cylinder to with the kit rather not waiste my time and get the best bang for my buck $
 

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Discussion Starter · #5 ·
Xcrs440 I haven't yet but the motor is all stock and never rebuild it has 5500 miles on it so I think is time no matter what the run out is
 

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It matters a lot. I am not sure, but I think Xcrs440 meant to measure the runout prior to teardown. That's a priceless benchmark.
 

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If you do this right and start with getting yourself a dial indicator and take the measurement from the pto, knowing your engine has over 5,000 miles I will gladly take a guess. I consider 5,000 miles the first hurdle. Seeing it lasted that long, then I consider it was both well maintained and working right. Maintenance to me is a little more than spark plugs and keeping the carbs clean. I use the term generically.... lol But seriously, whoever rode those miles played a large part because there are too many things that can go wrong.
 

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Discussion Starter · #8 ·
Dagg44 thanks for the info I'll check run out and ECT and do a leak down before it comes apart the guy I got the sled from was 50 and he said it was to much power for what he used it for all updates he said are done to the sled it was always taken care of stored dry and inside
 

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Dagg44 thanks for the info I'll check run out and ECT and do a leak down before it comes apart the guy I got the sled from was 50 and he said it was to much power for what he used it for all updates he said are done to the sled it was always taken care of stored dry and inside
You are peaking my interest with MCB + the coolant pump + a good running engine + the willingness to measure the current engine. If we wanted to, we could pull our minds together and do something worth our time and effort. I have worked in parallel with another member that was also working on an 800R, but this time I would be doing this with a 995 SDI.

If you are willing to spend the time and effort, this could be cool experience for the both of us. Assuming the engine is running well and you are willing to rebuild, I have to wonder if this is xmas in Summer. Name me the terms. For me this needs to be about the person. I have trouble caring for pieces of aluminum.
 

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Discussion Starter · #10 ·
I'm very interested I'm learning as I go and I love the sdi revs I have a few myself.... lots of people I know hated them but once you figure them out there really easy and very reliable if your willing to work together we can get another form of contact going and we can sort stuff out and get building I was thinking about best options for this 800r I have hate having to ride and worry about it blowing up all the time
 

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It sounds like fun. I look forward to compare notes.
 

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I have an original engine from 2005 with none of the updates that went over 7000 miles before the center bearings started to make noise. Others have reached over 10,000 miles and even 15,000 without the engine ever coming apart for repairs.
 

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Discussion Starter · #15 ·
Hey daag44 here is that mod guys do to the p-tek let me know your thoughts on it


YouTube .... (rotax 800 ho p-tek crankcase oil channel mod )
 

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Hey daag44 here is that mod guys do to the p-tek let me know your thoughts on it


YouTube .... (rotax 800 ho p-tek crankcase oil channel mod )
That is the one that I have seen posted on DooTalk. I have to say that I am not not into that mod, not even close. The maintenance work that you do to the bottom end is far superior, and it is at the high end. The way that you explained the reason for the inspection and what to look for had me wow'd. I learned from guys exactly like you. The advantage that I got was learning from a considerable number of people with their own variations. At the owner level like ourselves, it reaches into replacing the outer bearings and repacking the inner ones while the outer ones are out, but I have not gone that far.

In 2014 I chose to shift my focus on diagnosing, testing and learning from the higher mileage sleds. It happened following a conversation I had with someone knowledgeable from DooTalk who spent the time to show much of what I had learned and continued to be confused with was from claimed reliability upgrades that were never proven. The lessons were carried over to an ongoing conversation and work that I had already started with another DooTalk member near me. We have since applied a method of bouncing ideas and double-checking our work that has paid off.

When someone would post having reached over 13,000 miles on an 800R E-TEC without ever opening the engine, this is something that we needed to scratch our heads. The 2013 that he bought new has finally passed 10,000 miles without opening the engine. It was ridden by several people including myself, but maintained by one person. It would never have reached past ~5,000 miles had we not figured out how to fix the many problems early. Thanks to the members on DooTalk we knew where to look. I did get to check the runout of the crankshaft and clutch before this happened. That was around the time that I was checking a lot a sleds and realizing the maximum spec was not realistic. It took someone from Alaska working with his son on the runout to point this out before I grew a little more confident in what I was measuring. Eventually I got the measurements from a high mileage E-TEC which I consider the holy grail.

From what you told me, chances are that 800R is in great condition and only requires the level of attention that you have given your other sleds. Since you have two 800Rs and both are in perfect working order, this is a perfect situation to make use of the comparison method and adding to your current maintenance regiment with passive testing. An example for the lower end is testing the inner seals. For the top end, this would be compression, and if one test does not jive then there are 14 other points to consider. It may appear a little much for compression, but it's no different than having a toolbox equipped with a good set of tools. On a healthy engine I only need one of the fifteen.

There are too many things to check for preventive maintenance that will eat away time and effort. Half of it is trying to figure out what to spend time on because it is endless. There is no way that I am going through all the hairs of each engine as it would drive me bananas. I have seen a partially stuck ring that got me nervous and thinking should I check this on all engines? Sure if I have it apart for a full inspection, but otherwise I use preventive methods to steer away from having to do so. It is more about method than seeking perfection which is not even attainable.
 
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