2005 Summit Rev Burndowns! Please help me figure this puzzle out!

[PJ-Hunter]

I have a 2005 800 Summit that gave me nothing but burndowns last season! First I installed a RKT 827 BB kit and it burnt down after 4 rides. Don't know why. I put the stocker back in and it burned down in less than a mile!(aluminum coating the plug on the mag side) I took it to the dealer and after they looked at it they came to the conclusion that the MAG side crank seal had been leaking. Now that would explain everything, RIGHT? After the rebuild and $1000+ later the sled was running.

After the second ride out the frigging thing burned down again! the MAG side plug was covered in aluminum. I cannot, for the life of me, figure out what in the heck is going on! Would the timing cause a burndown? Cause BRP did a Re-curve for the RKT kit, but Kelsey says that his re-curve is safe for the stock motor too. What other things should I look for that may cause these burndowns?

I have another kid on the way and I cannot afford to keep rebuilding this motor every two rides. Plus my tow rope is getting worn out! Seriously, though! If anyone can help me with suggestions on what things that I can look for to alleviate this problem, that would be awesome.

I have had the RKT kit repaired from the first burndown and am gonna be installing it in the sled again. Hopefully you guys can help me with something to search for so I don't burn this on down again.

Here are a few things I have thought of:

Mid range jetting is screwed up or carbs are malfunctioning somehow.
would a DPM malfunction cause a lean burndown?
would the crank being whacked cause a lean burn down?
This may be a dumb question, but what factors can cause a lean burndown?

Please help as I am at a loss! Thanks

 

[mattymac]

Im assuming that the dealer who rebuilt it did a leakdown test?

Do you have any pix of the pistons that burned up?

If its just the one cyl that keeps burning up theres really only a couple of factors that can make it happen (if it truely is just the 1 cyl not both with the same condition but the mag goes first, which usually still causes damage to the other cyl)

Carbs have same jetting across the board?

 

[MOB]

Check carb boots, any pipe/stinger changes, crank phase, and going through the carbs wouldn't hurt.

Check for any pinched fuel lines/blockages...

If base gaskets changed (smaller) with RKT kit and you used same spec on stocker it may have raised stock compression/lowered squish...

As MattyMac says...pics help...but there are a few basics...good luck with it.

 

[PJ-Hunter]

Unfortunately I don't have pics of the second burndown. The third is still sitting in the trailer waiting for me to take it in for the teardown. I'll get pics then.

The two attached pics are from the initial RKT burndown.

 

[heinracing]

when you get it running, idling in the garage take carb cleaner or wd40 spray around all seals, carb boots to make sure you dont have a leak, if that shows nothing, check your jetting again to just make sure, how long are you letting it warm up before you take off down the trail? and how far down the trail till it lets go?

 

[PJ-Hunter]

I always let it warm up real good before I run down the trail. The first time I got 4 rides out of it before she burned down, but I was able to limp it back to the truck on on cylinder. The second time, I was literally burnt down in a 1/2 mile in deep snow @ full throttle and the thing just died in it's tracks. No limping back to the truck I had to get towed out. The third time was after a pull up a steep hill (thank God It made it up and over) and I was in deep powder and it did the same thing as the second time. Just died. I knew in my heart what happened and I pulled the plug and it was covered in aluminum! I was pizzed! I gotta figure out what happened and why!

 

[Macattack]

I've squeaked a piston last year and also this past spring. All were after long pulls ... turn out and it dies. Ran all season with no problems. But anyways, after talking with Kelsey we figure it was accredited to jetting. During long pulls, like 30-60 seconds, the cylinder temps creep up to the seizing point. This wasn't apparent during the majority of the season, due to throttle variables. Food for thought, I followed RKT's jetting instructions but ended up jetting fatter than what was initially recommended.

But, was mentioned ^^^^ ... leak down test or use the carb cleaner trick while running.

 

[tatorsalad]

burn down

I had rkt drop in kit in a 05 with a few burn downs it looks like you are not getting fuel or you have a air leak someone said check the carb boots they are junk with the 827 you need to run stock pipe and can pm me and i will give you my # if you want to talk about it some more

 

[Wheel House Motorsports]

i had an rkt 738 that it last 4 rides, then boom, clutch side burned down bad, and mag side staterd getting a little squeaked, then got that fixed, not very well, but got it fixed. then i burned it down, by rejetting for cooke as i didnt know it took the DPM a while to adjust, then i got the thing totally rebuilt. was coming back down the trail after my 4th ride and after a mile long straight, and lots of straights before that, the thing just stuck together. after it cooled down it would pull over, but there was aluminum all over the plug on the clutch side, i think the reason we see only one side burndown, is that the carbs arent 100% synced, and one runs just a little hotter or something like that. needless to say mine seemed like i should have jumped up a jet size or two. just weird how it happens so much, i spent way more than i should have this winter fixing my motor.

 

[winter brew]

Anyone else see a trend here ?? As said, do a leakdown test FOR SURE after the rebuild, if the dealer didn't do one maybe they will help you with parts since they should have cought a leak if this is determined to be the cause. It's either a air leak, timing, fuel quality for the higher compression or jetting. Good luck!

 

[Original Tetonice]

Consider the motor trashed thank RKT for that ......take the motor to Lynn Felker for a complete rebuild he's the best skidoo mechanic in colorado and don't settle for 2nd best.

2nd choice piddle paddle your way through it keep & spending $$$$$.

Next time you conside a mod consider having Trigstad do the work. Im curious did RKT even give you the time of day ? or did you leave message after message and no return call.

OT

 

[Powbuster]

I know how you feel blew 3 times last season . Dealer repaired fisrttime 1000 $ the last time I got pissed and did it my self found that mag side fuel delivery line was pinched this does cause lean burn also had water enter in through carb and air box water made it in to floatbowl not much but enough to block jet hense leanburn TO see if you have water drain floatbowl into clear countianer leave sit for15 min look for water bubbles. good luck hope this helps

 

[pinnedunderdoo#3]

you got to put oil in them or they blow up.....haha

 

[Sledneck26]

leakdown test?

Anyone else see a trend here ?? As said, do a leakdown test FOR SURE after the rebuild, if the dealer didn't do one maybe they will help you with parts since they should have cought a leak if this is determined to be the cause. It's either a air leak, timing, fuel quality for the higher compression or jetting. Good luck!

what is a leakdown test? how do you do it?

 

[NoSecondChances]

what is a leakdown test? how do you do it?

Depends on what we are talking about. Crankcase or cylinder? Basically for the case, you seal off the intake and exhaust ports and all other ports, then pressure up the motor and see if it holds, if it doesn't you have a leak somewhere, then you start pressurizing systems or eliminating areas and work backwards. A cylinder leakdown you bring the cylinder up to TDC, take the plug out and fill the space with water right up to the top of the plug threads, leave it and go back and see if the water level has dropped. if yes you have a cylinder leak. You can also do a compression leakdown test as well with a compression tester but there is a chance the pressure will leak out around the threads of the comp tester and give you a false positive result. Water is the best way to go.

PJ, Once you get it fixed and there are no leaks, I'd be starting with jetting based on what Macattack said, maybe jump up 5 sizes over what is recommended and start from there (go 10 sizes if you want to). Its easier to start way to fat and hardly run than to burn it down again. Go to F-Bomb's website and follow his instructions for setting up jetting and EGT baseline, this will give you a good idea of where you should be. I would also measure the squish clearance, do a compression test, calculate the head volume, compression ratio and make sure that you are using enough octane. Wiseco's website has an excel spreadsheet for calculating this that is really useful.

Three different times, two stock and one BB kits....you have changed several variables and still it continues, I would also be looking at what factors did stay constant in your motor during this time and go from there. Is your T-Stat screwed, is the head warped, are the carb boots leaking, maybe there is an air leak on the Mag side seal....things that have already been mentioned but like I said, something on your motor stayed constant during the changes and is maybe contributing to or causing the burndowns. Either that or each one was a freak conincidence with the mag side and you are most unlucky guy on SW. Good luck with it man!

 

[danf]

My 04 did the same thing after two rebuilds. Ended up being the carb boot
on the mag side sucking in air. I put in V force reeds and haven't had a problem since.

 

[milehighassassin]

Have you checked plugs? I mean check them before the burndown? I would do that leakdown like everyone is saying.
Have it jetted RICH
Then do an open throttle run, check your plugs and start dialing in the jetting.

 

[AKSNOWRIDER]

havent messed with the doo's much but carb boots, case seals(where it bolts togeather), carbs(jetting), and maybe weak fuel pump or collapsed/pinched hoses?also check your pulse hose that feeds vacuem to the pump,also how about wrong heat range plugs?

 

[PJ-Hunter]

Thanks for all the tips! Still looking for any other ideas...

 

[Kingpin]

Check all seals/gaskets for potential air leak. Lean burn downs are basically caused by 2 reasons. Not enough fuel or too much air. Verify jetting completely yourself. Richen up the main jet circuit 2 or 3 sizes and richen mid-range with a .020 shim or purchase a 5/20 shim kit. Leak Test that motor. IF you want, you can build a DIY leak tester. Search dootalk for a thread on building your own. If leak check is good and T-stat functioning put some miles on it varying throttle position, etc. Also, make sure you burp the coolant correctly. Check coolant level after some riding time add some if necessary. Retorque everything too. After you get a tank of fuel through it, do some WOT throttle pulls. First I would start out with 1/8 mile (just to be safe), then 1/4 mile, then 1/2 mile. Reading plugs and making adjustments on main jet circuit first, then repeat for mid-range(needles).
Read the following as a general guide to how you should work this process. IMO, trust nobody to verify things like jetting, etc, unless they understand everything done to your build. The mechanic doesn't have to get towed out or worse. Learn this stuff yourself and you will be much more confident and have a thicker wallet.
Baseline Jetting