JLO twin

[Todd K.]

I found this motor in the barn finds, is it anything special? or just another JLO, weird carb adaptor, and long starter cup? what did this motor go on? motor numbers  type, 2F-400-1   217 ... 398CCM   ps/n   motor number 399  36490

[Vintagesleds.com]

[JLOpower]

Doubt that it is special. A photo inside the starter cut would help. I'll bet it isn't JLO. Carb adapter is a GEM, not being used for it's original application. Cant for the life of me understand why someone would need to do that. The Tilly would work in the upright position. The reason can't be for steering shaft clearance.

[hotdoo]

Almost looks Ski- Whizy!

[chapguy]

Almost looks Ski- Whizy!

That's what I was thinking....

[Desmo878]

The reason can't be for steering shaft clearance.

It looks like that GEM adaptor would actually put it into the steering shaft! I have a few Ski Whiz's, & don't think that would work in any of them because of the steering shaft. That's why they used the angled intake. JLO made a straight intake, but it won't work in most old sleds for this reason. The super long recoil cup, not sure what to make of that???

[indybosch]

Probably put the long starter cup on for rope starts.

[zuknomad]

Probably put the long starter cup on for rope starts.

Yup, after the original starter puked and they didn't have the patience to fix it...

[skfox]

1970 -1973 Fox Tracs?

[wankel303]

Looks like a JLO 399 from a 1971 Arctic Cat Panther to me ( 4 bolts on the heads rather than the 6 used by the Cuyuna motors) but I am more familiar with the one-lunger JLOs than the twins.  The Cat would have used that down drafting intake manifold to clear the steering column.  Clutch would have had to have been swapped, the 45 degree G.E.M. Intake added and some "minor" modifications made to the recoil.  These recoils were fairly prone to issues and those little "stand-off like clampy-thingys" always disappeared in the shop someplace as soon as you took them off.

[JLOpower]

Almost looks Ski- Whizy!

The clutch and starter cup isn't, for sure. Massey's twin cylinder engines all used motor mounts that were 4 flat spring steel bars, so that motor plate is wrong for a MF too. The engine designation leads me to think it's one produced right around the time Rockwell sold to Scorpion. Still that doesn't narrow it down much.

[73400tk]

It wouldn't be a cat motor as its a 2F-400-1, the cat motor was a LR399-2 though it does have the angled up intake the both cat and massey did use. It could be from on of the many off brand sleds that used JLO. The 2F-400 motors were not used until 72. Its the high performance 400 with the extra transfer port and smaller bore. The 2F has 64.87mm piston and the LR has a 64.93mm piston. As well the rings and ring gap pins are different due to the difference in the transfer port. The 2F also used chrome spun rings while the LR used just regular carbon steel springs.

LR399-2:                28 HP
2F400-1 through 6: 43 HP

[Todd K.]

WOW, Thats great news, i thought that JLO  sticker looked different the others i have seen. im thinking of making a little hot rod PUMA, looks like a good power plant, THANKS FOR THE INFO!!!

[JLOpower]

The sticker looks correct for that era.

[Desmo878]

It could be from on of the many off brand sleds that used JLO.

My 73 Whip It, 73 SnoPrince, & 72 MotoSki have the LR399-2 in them, along with 2 Masseys I have. Pretty common engine back then in consumer type sleds. No hot rod, but torquey. Sticker is correct for them. Surprised it still looks that good!!

[scorpion tkx 890]

This motor is not a 2F as the cylinders dont have the welch plugs on the sides for the extra transfer ports. Looks like a LR to me