Soderberg, great info! Jerome Kretzman from C-shaft Services can do the porting and the head cutting if anyone has an interest in trying to make a go fast Trailfire. If you give him Soderbergs specs, a cylinder and a piston he can do it. For anyone wondering what a variator is, that's the technical term for the clutches. Soderberg, I'd be interested to see what you come up with as far as how much squish, dome and gasket surface you cut into or out of the heads. The 340 Trailfires will lift the skis, so with some light mods these things have the potential to be a quick little fan cooled sled.
~Jack
dual carb trailfire
-
guitardude081
- Posts: 990
- Joined: Sun Sep 11, 2005 12:00 am
- Real Name: Jack Durand
- Location: Brainerd, MN
dual carb trailfire
Owner, Durand Motorsports
1980 Trailfire 340 (Grandpa bought new)
1983 Trailfire LX
1982 Spitfire (Grandpa bought new)
(3)1974 295/S
1975 340/S
2020 Polaris Indy 600 XC 129 40th Anniversary Edition
1980 Trailfire 340 (Grandpa bought new)
1983 Trailfire LX
1982 Spitfire (Grandpa bought new)
(3)1974 295/S
1975 340/S
2020 Polaris Indy 600 XC 129 40th Anniversary Edition
Re: dual carb trailfire
To start with. I am Soderberg but couldnt logon with my old username. Had to create a new one. This is what happened with my Trailfire at the end.
1. I went for the LF porting.
2. As the intake looks as it does on the TF I had to make an adapter plate that connects both cylinders. Could have made them individual but as I have ended up with TM 36 racks this was the best solution. Today I use standard Mikuni intake manifolds. Also had to use some chemical metal to adapt the square intake to fit the adapterplate and the round manifolds.
3. TM 36 racks from a 1997 Vmax 500. Had to go down on the mainjets from 150 to 140. Have tried 135 also and they gave slightly better performance. Went back to 140 because of security. Pilot jet from 45 to 35. The needle clip in the highest position. I use Uni filters.
4. Shaved the heads 1mm.
5. I use the standard TF pipe but will probably try a single performance pipe later. Got rid of the Trail pipe as it looked terrible. Except for the carbs it looks as a standard TF.
6. Standard secondary clutch. Primary clutch now with A3 weights and a spring that I had left since 15 years ago. Engagement speed at 4000 RPM.
I dont know how many HP it gives today but if a LF gives 60-65 honest HP thisone gives 55-60. It revs 8200 RPM and the speedometer shows 75 mph on an hard packed lake road. Raced against a 1993 EXT 580Z and we were even to aprox 50 mph. So...... am I satisfied? Yes..... VERY
. Will not do anything more except for maybe that performance pipe. Even though it goes more than great and feels very reliable, Im still afraid that the engine is close to the limit when it comes to trustability. I still use this as the family sled. Will also try it for fun in a vintage dragrace at the end of this month. If it holds together for another 2 months Ill do something similar with a TF 340 next season.
Sheers/Ola
1. I went for the LF porting.
2. As the intake looks as it does on the TF I had to make an adapter plate that connects both cylinders. Could have made them individual but as I have ended up with TM 36 racks this was the best solution. Today I use standard Mikuni intake manifolds. Also had to use some chemical metal to adapt the square intake to fit the adapterplate and the round manifolds.
3. TM 36 racks from a 1997 Vmax 500. Had to go down on the mainjets from 150 to 140. Have tried 135 also and they gave slightly better performance. Went back to 140 because of security. Pilot jet from 45 to 35. The needle clip in the highest position. I use Uni filters.
4. Shaved the heads 1mm.
5. I use the standard TF pipe but will probably try a single performance pipe later. Got rid of the Trail pipe as it looked terrible. Except for the carbs it looks as a standard TF.
6. Standard secondary clutch. Primary clutch now with A3 weights and a spring that I had left since 15 years ago. Engagement speed at 4000 RPM.
I dont know how many HP it gives today but if a LF gives 60-65 honest HP thisone gives 55-60. It revs 8200 RPM and the speedometer shows 75 mph on an hard packed lake road. Raced against a 1993 EXT 580Z and we were even to aprox 50 mph. So...... am I satisfied? Yes..... VERY
. Will not do anything more except for maybe that performance pipe. Even though it goes more than great and feels very reliable, Im still afraid that the engine is close to the limit when it comes to trustability. I still use this as the family sled. Will also try it for fun in a vintage dragrace at the end of this month. If it holds together for another 2 months Ill do something similar with a TF 340 next season.Sheers/Ola