340 Drifter Fan Cooled Engine Specs

[Tory944]

  Hi guys,  Back again in need of more info!  I am looking for engine specs for the "Fan Cooled" 340 Drifter.  Specifically, hp rating, max rpm, stock carburetor size, etc.  The engine tag I have reads TA340A-C201.  Must be a 79'??  Any info would be great!  Working on a secret weapon!  LOL.   Thanks!  Tory

[mswyka]

Yeah Tory, that will make a sweet engine for the Gilson

[rminier]

 The service manual shows shift speed of 6300-6500 RPM...idle 2000...engagement 3500.
  Mikuni VM-32 econo jet..marked 32/143.
   Main.  230
   Econo.  110
   Pilot.   25
   Needle jet.  6FL14-3
   Needle.     P4
   Cutaway.   2 mm
   Air screw.  1.5 open
   
It shows the stock gearing...17/38...good for 58 MPH at 6800, clutches at 1/1.
   The 440 used 21/38 gears...72 MPH at 6800..
No info on HP...somebody on here will know.
 Just guessin'...32 @ 6500.

That would make that Gilson HAUL! Mark has your "secret weapon" figured out??

[Interceptor398]

30 HP

[Tory944]

Huh...   For some reason I thought I had seen hp ratings for the F/A 340 @ 28 /  340 Fan you guys say is 30 and I thought the 440 Fan was around 32 hp.  Something doesn't seem quite right   Those fan cooled intake ports are considerably larger than the F/A and feels like a much larger gain in performance between the 80' F/A and Fanners.  Four horsepower spread?  I dunno.  Either Kawi underrated their Fanners or the F/A 340 Drifter isn't pumping out 28hp!!  Thoughts??

Mark....   You would make a great comedian...

[rminier]

 Here's a few comparisons. My 75 SnoJet has a Yamaha Y338 motor, piston port, single VM-32, that has a claimed 32 @ 6500. I believe that the 79 and later Yamaha Enticer 340's were right there, also.
  I have an ancient service manual for dozens of brands up through the 77 models. It shows the 340 Cuyuna motor, with a single Walbro, in the Scorpion 340 Whip at 32 @ 6500.
  I know the Yamaha 440 Exciter had a reed-valved motor ported a little hotter that put out 48 @ 7000.
  I "think" that Yamaha also had a 340 Exciter up to 1978 that was also reed-valved and put out 38 @ 7000.
  The Intruder must be in the neighborhood of the 440 Exciter with the same 7000 RPM power peak. The 440 Drifter must be around 40-42 @ 6500, I'm guessin'.
 But, the 30ish power for the 340 Drifter sounds about right.
 

[Interceptor398]

The sheet I have says

F/A   28 hp
340 Drifter 30 hp
440 Drifter 45 hp
440 Intriger 48

81 drifter 340  34 hp
81 Drifter 440 43 hp

Not sure what makes the Intriger little hotter??

[Tory944]

That's great.  Thanks!  I guess my 440 Drifter has a few more ponies then I thought.  That would makes sense as there is no comparison in power between my Drifter F/A and my 440 Fanner.  Interesting numbers.    Tory