Dax F80 Engine

Discussion in '2-Stroke Engines' started by Timbone, Mar 11, 2015.

  1. Timbone

    Timbone Active Member

    This afternoon, I swapped out my generic HT for the Dax version of the HT two stroke engine. I paid $149 for just the raw engine. I had all the other stuff.

    Man, this thing started on the very first pop! Bam! Very smooth and good power all over the band. Since it was a break in run, I satisfied myself with burning up about 16 ounces of fuel, and though I put in some good fast runs, I never went WOT.

    Since I now know that all systems are go, I am going to backwards engineer and red locktight all my motor mount hardware. My front u-Bolts need to be trimmed so I can get wrenches in there if needed.

    I am gonna get a new rear wheel, just to be safe. I am really hoping that this is the start of a new level of reliability.

  2. Timbone

    Timbone Active Member

    Update: better weather has me back on the road. This Dax motor is wonderful! It just goes as soon as your pop the clutch!

    Feeling good about my motor mounts. I use KC's test: grab the top tube with one arm and push the engine hard. I had a hint of deflection. and learned real quick that the two rear motor mount nuts could use a little tweak. All of the bolts on my mounts are touched with red or blue locktight. On yesterday's run, the exhaust nuts loosened up - they've now been tightened back with red locktight. And, wouldn't you know it, air filter bolts loosened up. More locktight applied - blue for these.

    Striving so hard for real reliability. When I get motivated I will get to work on the new rear wheel.

  3. desertsteve60

    desertsteve60 New Member

    Just signing in on this thread. I got one of Dax's 40mm stroke bottom ends last year and love it. I've been through 3 top ends but the bottom end still feels as smooth as the day I got it. One thing you might want to check on is, the screw for the small bevel gear(primary gear) came loose on me once, but after I generously blue loctited it and got it tightened up good with a impact screwdriver it never gave me another problem. This a daily driver for me and I figure I have at least 5K plus on the bottom end, it should be a pretty good motor if you leave it mostly stock. I have a 6cc Fred Head and a Arrow Torquer II pipe with a Jag. ign.(for reliability not performance) and mine feels like it will run forever(fingers crossed, knock on wood).
    Timbone likes this.
  4. Timbone

    Timbone Active Member

    Yes, this DAX motor is a definite improvement over my first HT motor. Good torque, good bottom end power and it winds out very smoothly.

    I had this set up to be free of the need for a chain tensioner but, even with chain tugs on the rear, the chain was moving just a tad too much for my satisfaction. I set up my custom fabricated chain tensioner to take up just enough slack to prevent unwanted chain slap and reinforce the chain line. I am cruising now!

    I am hoping that this will get me up to motorcycle level of reliability!

    Thanks for the feedback; I'll keep an eye on that bevel gear!