670 Rotax Needs rebuild SOLD, SOLD,SOLD

[givemeaboost 4]

I don't see too many people here running the 670. I've got a 94 model out of a Skidoo Mach1 that I've heard is one of the good years to use for aircraft. The cylinders and pistons looked good but the crank needs to be rebuilt. It would make a good parts engine.

 

 

Ken.....................

Edited 12 Oct 2016 by givemeaboost

[THE MACHINIST 35]

What are you asking for it?  Does it have a pressed crank or can the rod caps be taken off and new bearings be put on by a regular guy?

 

thanks

jamie

[1avidflyer 2016]

I believe all Rotax engines have pressed cranks.  The right shop can rebuild them, although I don't think Rotax approves that.  Rotax does make tons of money selling parts however, so that has to factor in.  I had the shop I take my engines to rebuild a Cuyuna 2 stroke crank for me with no issues.  They replaced the main bearings for about $100.  I know that Steve Beaty at Airscrew Performance can rebuild Rotax cranks.  Not sure what he charges though.  JImChuk

[givemeaboost 4]

 Thanks for the info 1avidflyer. I've never seen a 2 stroke without the pressed together crank but there might be some out there. As far as the price, I'd like to get $400 for it.

 

 

Ken....... 

[THE MACHINIST 35]

I was afraid of that.  Rotax Rick gets a lot to rebuild these.  Plus the crank will need machined. 

[Dusty 126]

Check the Pto end of the crankcase,some 670's just need machining and drilling to fit the "c" or"e" box,the later 670's were cast differently and aren't practical to use.

The crank rebuild is practical and affordable (rebuild kits are available ) have a talk to Rotax Rick,

These are an awesome motor with a better power to weight than an 80hp 912! but long term reliability has yet to be proven.

[givemeaboost 4]

I don't think there is any machining involved. The press the crank apart and put new bearings on the rods and mains and use new pins to put it all back together.

 

 

Ken..........

[THE MACHINIST 35]

The end of the crank will need machined to a taper to fit the c or b or e gear box 

[C5Engineer 1170]

From some old email traffic between Rick and I when I found a cheap sled a while back and asked about the 670 needed. The others besides what he describes will not accept the ducati stator to make it dual electronic ignition.

 

The 1993 or 1994 engines.  Make sure it does not have the black cap or 1 1/2 inch hole in the case between the mag cylinder & recoil starter.  

The 670 burns 1 gph less in gas so that will help.  The Interceptor is the best oil & 40 to 1 is a must.

Remember 3 out of 5 582's that fail is the lower rod bearing burns out. 

I been building the cranks since Jan. 1 2011 & have not had a single 582 lower rod bearing fail. 

Edited 9 Oct 2016 by C5Engineer

[givemeaboost 4]

The crank is already tapered. This motor came out of a Skidoo that was built in 8th month of 93. Also, this engine has all the booses in the pto end that need to be drilled and tapped.

Edited 9 Oct 2016 by givemeaboost

[THE MACHINIST 35]

Are the carbs or exhaust included?

where are you located?

Are you willing to ship if so any idea of cost to 83864?

 

 

thanks

[givemeaboost 4]

I can ship it. The carbs and exhaust y-pipe can go with it. I'll see what the whole lot will cost to ship. I'm in Montana.

 

 

Ken........

[THE MACHINIST 35]

Where in MT?

[givemeaboost 4]

Great Falls

[sioux201 86]

I think what this gentleman means re crank taper,yes it is , BUT you will have to ENLARGE the tapered hole for it to work on a Rotax gearbox!!!!!!

[sioux201 86]

Also ,if I remember, shorten the 670 shaft 14 mm

[givemeaboost 4]

I sent you a message.

 

 

Ken..............

Are the carbs or exhaust included?

where are you located?

Are you willing to ship if so any idea of cost to 83864?

 

 

thanks