[gpr]

Last year we pulled the ricky stator flywheel off the crank and it pulled a big chunk off of the crank and ruined the shaft and had to be repaired. was told it was from the ricky stator flywheel. This year got a new crank and new oem flywheel. had tranny issues this year and didn't put much time on the engine at all. I pulled it down last night and noticed the flywheel just started to weld itself to the crank again. this is a brand new billet crank and brand new oem flywheel, why does this keep happening?

Last time crankworks told me to put grease on the crank tapper and flywheel, then red lock tight the nut on. Did this and it still having the same issues. if we put more time on the engine and i pulled the flywheel i know it would of ruined the crank.

So what can i do to cure this for good?

[tripledsracing]

lap it and then use red lok tight!..did the key break?..lapping compound should do the trick w/lok tight!

[gpr]

i have read to lap it and red loctite on. How exactly are you lapping it? put valve lapping compound on the tapper of the shaft then put the flywheel on and rub it back and forth? how do you know how much or how long to do that for?

also do you put red loctite all over the tapper of the crank and flywheel then torque to factory specs?

the key did not break and all was tight, so i don't understand how it could even be moving to cause the problem????

[Radar]

I use regular rubbing compound on the taper and spin the flywheel by hand till the flywheel and crank are mated fully. The flywheel will get real hard to turn. I then use blue loctite on the crank taper and the threads. I think having them fully mated gives it less of a chance of having that galvanic type reaction due to the flywheel being grounded better to the crank with more area.

[banshee(911)]

hmm good info here!

[bubba297]

Use a blue or red fluid layout dye and coat the crank taper with it. If you cannot find the layout dye locally, then use a black permanent marker and color the crank taper (of course after cleaning it lol). just like seating valves in a head, once you get the surfaces mating correctly, you will rub off the marker. ANY high spots on the crank or flywheel will cause them not to seat correctly. A slight low spot or shadow would be acceptable since it really wont cause an issue, but if it is a big area then keep lapping. I personally do not use anything on the crank when installing the flywheel, IMO a clean dry taper fit is the best way to go. The key is only there to time the engine, and does nothing to hold the flywheel from moving. That's all done in the taper fit. Hope that helps, Bubba

[gpr]

Do you guys torque the nut to factory specs? i can't remember it off hand what it is, but i always put it to what the service manual says.

also once you lap the flywheel to the crank is it good to remove and reinstall, or should you lap the flywheel every time you reinstall it?

[Moser Racing]

have seen this before on snowmobile engines, big offset timing keys cause issues, flywheel bottoms out on key and not taper making for a big mess. check crank key groove also, have seen some aftermarket cranks with a smaller key slots. hope this helps.

[tripledsracing]

gpr, on 07 October 2010 - 07:13 AM, said:

Do you guys torque the nut to factory specs? i can't remember it off hand what it is, but i always put it to what the service manual says.

also once you lap the flywheel to the crank is it good to remove and reinstall, or should you lap the flywheel every time you reinstall it?

i usually just take a impact and run the nut up til it stops turning but put red lok tight and then if need removed use a lil heat!..once u lap it you should be good to go,i only lapped mine one time and ive had it off 20+ times now..

[Radar]

Lap it just once. Unless you are using a different flywheel or crank. Seems like the billet cranks are worse about this from seein posts like this over the years.

[roach]

I have battled this issue also. I have found that billet cranks are much more likely to have this problem. I personally have never have a forged crank do this but every billet crank I've used, and friends of mine have used, had this happen. I believe the billet cranks are made from a softer material. I know billet cranks are suppose to be the best but I think they suck. Just my exsperience.

[gpr]

Funny you brought this thread back up. I was re-reading it the other day. I lapped the crap out of my flywheel and crank. Then coated the taper of the shaft and the inside of the flywheel with red locktight. I also torqued it on to 80 ft. lbs instead of 60 like the service manual calls for.

Honestly if this happens again, i simply think i'm gonna drill a couple holes in the flywheel so i can access the stator screws. This way if i ever need to split the cases again i could do so with out removing the flywheel, and let that sucker weld on there solid.

I wonder if anyone has ever built a billet crank with a forged stator web? that way the stator shaft is forged and wouldn't weld to the flywheel... Was another thought I had as i'm tired of ruining expensive cranks.

[okbeast]

I was told if a crank/flywheel was lapped properly, putting loctite on there would make it damn near impossible to ever get off. It's amazing how much friction can hold.

[gpr]

Bring this back up to get more opinions. I opened this thread years ago. Tore the same engine down again this year. SAME PROBLEM!!! I could not believe it but the dang flywheel welded itself again. I have tried just about every way possible. with grease, with locktite, with out, lapped it several times..... I have tried multiple different crank keys, three different flywheels now and every time i pull the flywheel its welded to the crank. the longer the engine is ran the worse its welded, luckily the tranny was a piece so we didn't get any run time.

A day on the dyno and 10 minues of dune time max on the engine and the flywheel was already welded on.... anyone else have any ideas or advice?

[okbeast]

By welding are you implying a metal to metal bond? For this to happen it would have to be at a temperature that would destroy other components.

If it is lapped correctly and torqued down after a heat cycle, there would be such a small area for loctite to be it's pointless to use.

On the other hand, I wonder if the loc-tite is what is "welding" it together.

[gpr]

I have tried it with and with out locktite. this last time i lapped the crap out of it and till it had perfect contact all the way around. cleaned it off with brake clean on the shaft and flywheel. then i torqued the nut on. it still welded itself.

And by when i say welding itself i mean when i pull the flyweel off it actually pulls chunks of metal off the crank as it is "welded" to the flywheel. i'm guessing it is electrolysis. sorta like when you put lead weights on aluminum wheels overtime something creates a bond between the two from two different types of metal.

I can't possibly be the only person with this issue, as i have talked with several builders and crankworks and they have all seen it. however everyone's recommendations have not worked and this has happened year after year after year!

[okbeast]

I have a crank that looks like that, but it was from the key coming loose. I have actually seen quite a few that look like that but I've never had one welded on.

[gpr]

Not only that but i was thinking and really it isn't the key holding the flywheel in place it is the friction from the taper fit. the key is only to get timing correct. Heck my 150hp snowmobile with a primary way heavier than a fly wheel doesn't need a key and it has no issues.

Its gotta be something with the two different types of metals. Crankworks should start making flywheel hubs out of the same material as their cranks so it isn't an issue.

[cphatt]

what stator are you using ? oem or aftermarket.we had this problem with ricky stator 200 watt stators.

[Mailman]

Just thinking out of the box here but..........

What stator cover are you running? It seems like the billet stator covers would hold more heat in than the oem plastic ones.

also........

Are the drag pipes on the left or right? I would think having the pipes on the left would block air to the cover and keep more heat in that area.

I may be out in left field so take it with a grain of salt.