Sx Viper 700
New member
I have a 78 enticer 250 that I swapped an 81 enticer 300 motor in and bolted on a mikuni tmx 38mm flat slide carb and I don’t have the original enticer 300 clutch so I was wondering what the best clutch to buy would be?? I’m looking to use the sled for 1/4 mile snow ovals I was also wondering what the best gearing set up would be it still has the 250 gears in it??
2 of my uncles had the et300 special and my dad had the et250. they always raced them and whoever got the jump would stay out front all the way, so i would think the gearing would be the same. now at the gas pump, the 250 was always taking more gas than the 300's.
The original two arm roller clutches were really good.
However, I'd recomend the CV tech style clutch as its easy to tune and low cost.
Stock gearing should be good. I recently GPS'd my 78 250 at 59mph.
However, I'd recomend the CV tech style clutch as its easy to tune and low cost.
Stock gearing should be good. I recently GPS'd my 78 250 at 59mph.
powerblock would be nice too if you get all the tuning stuff with it. had one on dads 78 et250 and that little bugger would outrun et340's on the lake. tec didn't give us the tuning parts so bottom end sucked.
Sx Viper 700
New member
Where would you get a powerblock?
they sold out to cv tec. that was back in the 80's when that clutch was put on.
How did you get that clutch on a 78?
Did you switch the crank out to the 1980 version?
It's now called Umatek.
BornYamaha
Member
I am sure you could gear it down some if you can find the gears. I am pretty sure they are not available from Yamaha anymore. I am one tooth down on the top gear on my little 250 with the only engine related change being a 34VM Mikuni. I got 62 MPH GPS on a long run on a hardpack road with little resistance this year. I am about 180lbs. My point is it was not over reving to get there. It was at about 7,000rpm. That where my shift rpm is set at.
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back in the day they made a clutch to fit that crank as that was done back in the late 80's.
Cool. I wasn't aware of that.
On my enticer 300 with 38 vm carb no air box... i run an old school 1984-89 phazer clutch on it. 8V0 ramps with silver-silver spring.
gearing is 13-22. Good Luck have fun with it.