DJM, I haven't sent my stuff out yet so there's still time to switch directions and, the info you gave me is exactly what I was looking for!!
I'll sell the 700 parts then and go with a 770. I'll talk with Big John and have him do the job I spoke with him when I blew up the 600 and he seemed like an awesome guy as well as being super knowledgeable. He definitely did not like the TMX race carbs and said run TM40's.
I'll cut my own case half on a drill press as the sleds coming apart anyways.... I burnt a pto ring at 500 miles on the RS motor.
Can you clarify some specifics on your setup as you obviously know what works...
-I know to pick up a set of 800ho cylinders and, I'll have them fully ported by BJ.
-What head are you running or does BJ take care of that side of things? RKT unit DMAX?
xxx I never used a DMAX part. As I recall, have an RKT head on one of them and Big John used an 800HO head with the domes cut out and new domes inserted. It has been so long ago that this was done, I will have to go look at both sleds to be sure.
-What year/model summit pipe are you talking about that you're running? Any reason to not get an SPI pipe or DMAX unit or is it just not worthwhile when compared to an OEM?
xxxx Duramax pipes are hard to find. TT670 had one, he is he one that got me going on the 770 as he had built one. I believe it was a 2013 but I will have to check, see if I can find the old thread on the subject as I detailed everything we did and used.
-With the TM40 carbs (I'm assuming 800r units) what reeds and boots are you running and did you swap to oil injection? Any concerns with the 600rs airbox and TM's? I'm running a custom MOD half aluminum airbox on a summit dual intake side hood for max air flow. I'm pretty sure I can swap out the rubber carb necks in the box to fit the larger units if need be but. (Not sure if the OD on the inlet neck is the same).
xxxx I used TM40's and Vforce reeds and manifolds (bought some Boeysens and still have them in a box in the garage. Just couldn't install them. Too much aluminum for heat pickup and essentially solid mounting the carbs with needles and seats didn't seem like a good idea to me. Know lots of guys use them. I have oil injection on one sled and premix on the other. Kind of wanted to see if the results would be the same and how much trouble it was using premix. Had equal success with both. I would use non 600 RS stuff for airbox and inlet.to match with the TM40's. I don't remember why AdamAdam had so much trouble and bad memories as mine have all been good. And these two engines have been super reliable. I will have to go back and look at some of his threads. Don't remember if he use TMX or TM carbs.
xxxx I do know Big John won't steer you wrong.and his engines will be reliable. When I did mine, I bought two 600RS crankcases, one with crank and one without. from Twinpower on here Rene and his dad are super. Big John happened to have a super 600RS crank at the time that had come out of Trgystad engine that he used in the second one. I was so happy with the first one, I could not wait to get a second one. Anyway my old thread on the the subject had the exact pipes I used with ID of the stinger outlets. if I can find them. Jetting as I recall is within a jet size of what I was
running on the ported 700's
My sleds being completely redone and made more trail friendly/ setup for the area I ride-
Swapping out a 1.75 paddle and 25/49 gears for a 1.5/1.25 Storm track with 90 studs and 25/45 gearing. Looking to redo clutching as well to be a little softer on launch as it just trenches like a mofo with the setup I have.
xxx If I can't find where I have the info written down, I can pull my clutches apart and tell you what I am running for clutching, I know I have Joey's helixes in both sleds, with DooDoctors floaters and I want to think the ramps are 412's but I would have to check to be sure. seems to me pin weight was in the 21 gram range and I typically don't like high engagement speeds but would have to look to find what primary springs I was running. Ha ha.. know you can run a RS flywheel with the standard twin pickup so you can have RER as I tried that initially and for some reason it limits you
to 7200 engine speed. That was my biggest hurdle when I got the first one built. I thought the two 180 degree short pickups on the RS fly wheels would work for RER and then did, but as mentioned it limited the sled to 7200 rpm. Just changed the flywheels to production engine flywheels and walla I could run whatever max rpms I clutched for. Memps were XP 800R with Ski-Doo installed hot 700HO curves in them. But the production 899R memp curve works just fine.
Once again thanks for all of the info it's appreciated!
xxx Based on some of the DMax 770 stories, I am glad I went with Big John. Oh should add with the 700's I had cylinders ported by BJ, Trygstad, RKT, Chuck Walthers and one or two others
There is a reason why I keep going back to BJ. Not sure who the guy is that ports for him, but he is good!