Modified GX200 on Alcohol, Pros and Cons

This last week I bolted on a Tillotson HL-348F Alcohol carb to my Honda Clone GX200. At this point the motor is quite modified and it was time for a bigger carb. The last trip out to the track I was running the ARC Blueprinted carb but on a motor with a .275 lift cam on 1.3:1 rockers it was no where near enough. As of today, my current set up is:

  • Ducar Clone GX200
  • ARC +.020 Billet Rod #6271
  • Honda Flat Top Piston STD
  • ARC Billet Flywheel – Non Adjustable – No Flywheel advancement
  • Robertson H-Loop Header
  • DynoCams .275 Lift Cam
  • 1.3:1 Rockers (Non Billet) & Billet Guide Plate
  • Ported & Decked Head with Big Intake Valve
  • HL-348F Tillotson Carb with ARC Billet Manifold
  • Draggin Skin Clutch with White Springs

Ok, so the pros of this configuration is that it was VERY FAST. I gave two 125cc Parilla TAGs a hard time in the corners and pulled them at the end of the straight-a-way. My peak RPM was 9,200 RPM and the motor had more to give. I did not have time to mess with my gear ratio and my clutch was slipping really bad. The Draggin Skin Clutch performed ok the last trip out to the track when I was still running the stock carb, but now with the extra bottom and top end the clutch is worthless. I would say that the Draggin Skin clutch is not really good for much more than a stock motor. You can change springs to get it to engage at different RPM ranges but when you get enough power the shoes will just spin inside of the clutch and you will eventually smoke the clutch, like I did. I actually have not seen a clutch smoke that bad since Yamaha’s used to run oil filled clutches back in the day. Because the clutch was slipping so bad it was hard to tune the carb. The throttle link is such short throw that it felt that my throttle was simply an on and off switch. I did not think that it would be as big of an issue as it was, but with the motor responding so well when the clutch did grab it was hard to keep the tires connected to the track. It ran around 330 degrees which is pretty good, if the clutch had been hooking up I could have tuned things in better and probably warmed the motor up a bit. My goal was to run somewhere between the 380 to 400 range.

The cons… The HL-348F Alcohol carb is a huge 1″ bore carb. Though I have the head ported with big valves I am afraid it may just be to much carb for the motor. I ran the low speed needle at 1/2 turn and the high speed at 2 1/4 tunes, which is really weird. I ran the kart for about 10 laps 4 different times out. The third time out I was just getting things to work well and my silencer fell off. I kept running because my pipe bracket was still connected. I suggest bracketing your headers, especially if you run the big H-Loop header. Right when I felt that I finally got the carb tuned in, I smoked my clutch. It was bad, almost as if the chain had came off. My momentum kept me moving and I made it back into the pit area. At this point it had began to sprinkle a little bit so we packed up and left.

To be honest I am/was a little nervous about taking a stock Honda piston past 9,000 RPM. I will be taking the motor apart to see how the piston has been wearing. When I took the stock clone piston out there was a lot of wear on the piston for having less than an hour of run time on it. I was very surprised how well the motor held up. It ran like a champ and pulled like crazy. These clone motors really are decent for their price. I don’t plan to do much else to modify this clone motor. I don’t want to push it’s limits much higher. I am not looking to blow up a motor.

With the exception of the clutch and the carb being a little hard to tune I was very happy. With the right clutch, gearing and more time to tune the carb, those Parilla TAGs won’t stand a chance.

I will write up a review of the Draggin Skin clutch now that I have ran it to it’s limits.

Author: Jerad Hill

Husband, father, business owner.

2 thoughts on “Modified GX200 on Alcohol, Pros and Cons”

  1. 1/2 turn on the low and 2 1/4 on the high? WOW! That is strange!
    What clutch do you plan on running next? Is there still a Horstman available or something else? Also what tire and compound are you running?

    1. In the 4Cycle forum I actually received a reply from EC explaining that my carb settings were backwards. I had actually started off at their suggested settings per a post I had read previously. I am going to check the pop-off as suggested and try it again.

      As for the clutch, I am going to try a Horstman Reaper Clutch. I have one but will need to order a different size driver for it. I am not sure if I will be able to get it on the motor with out having to space it off the end of the crankshaft, which I am not very fond of that idea. I may also have to move my seat to get this clutch to fit, something else I don’t want to do.

      Anyhow, maybe if the stars align, I can make it to the track to test next weekend.

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