help: atc90 sluggish in high range but not low

[n10sivern]

my act90 restore/rebuild is up and running but it isn't running quite right. the carb still needs some adjusting as do the points. i drove it around today and it is really sluggish in high range. i didn't even notice it until i switched to the low range and it ran much better and wasn't near as sluggish. is there a reason that it is bogging down in high and not low?

[money89tractors]

High range takes a lot more power to pull the trike. I have only ever had one 90/110 that would pull itself through all 4 gears in high range.

my 79 (i think) 90 would pull itself well in high range in 1st and 2nd gear, once you hit 3rd it had 0 power.

I always run my 90/110's in low.

-Phil

[ParrotGreenUS90]

The 90's tend to need the low range to move well. I do have one 90 that was given a new bore, I think .25 over, and it will go through all 4 gears in high range with out any issues. If you were climbing a hill I could see having no power. Are you using stock size tires in the rear?

[n10sivern]

Using new 22x11x8 duro knobby tires and I was on flat asphalt.

[ParrotGreenUS90]

What is the history of the motor? Maybe it is wearing out and needs a bore. The one I have was bored out .25 just before I got it and will move great in all the gears. I am using the 4 Snows and can haul a few ice shanties and have pulled a trx200sx off a lake in 2nd gear high range. I would say give it a bore.

[n10sivern]

It's bored over once, has all new gaskets, and 148-150 compression. Doesn't smoke. It is the original 1973 motor.

[daniel_250r]

how much do you weigh?

[n10sivern]

6'3" 200 pounds.

[daniel_250r]

it might just not have the power to pull you it is only 90cc. but it could pull you before right?

[ParrotGreenUS90]

Do you have the brakes adjusted properly? May have the power in 1st and 2nd but not in 3rd or 4th due to the drag. How does it roll, I can do the neutral between gears and can roll a few houses, about 100 feet before it comes to needing to go in gear and go. I have had brakes drag and they are not worth anything but low range.

[n10sivern]

I'll have to check on the brakes. I don't believe that'll be the problem as it rolls easily in neutral. In it's day, this little 90 would tote me at 150 pounds and a deer of equal weight.