GX160 Throttle Question

Jeff Neal · Posted: Sun Jun 26, 2011 8:07 pm Post subject: GX160 Throttle Question

Hi, this was our first weekend autocross racing my son with a very new and very stock Honda GX160 engine. My son is complaining that it doesn't feel much faster than his Comer 50, and I admit I expected to see more of a difference.

One thing I see on the engine is a "2 stage" type throttle with the 2nd stage activated by magic (or maybe vacuum). Can anyone tell me how to know if this is working correctly?

Thanks, Jeff

John Matthews · Posted: Mon Jun 27, 2011 4:05 am Post subject:

Hi Jeff,

I don't know that there would be much difference between the Comer and a GX160. AFAIK there isn't a "2nd stage" to the carb but if the engine is totally stock there is a governor that keeps RPM down to ~3600. You really need to put the governor (completely out of the engine) to have a satisfying kart driving experience. What are the rules where you run?

Cheers,
_________________
John Matthews
Heartbeat Power, LLC.

Jeff Neal · Posted: Mon Jun 27, 2011 4:45 pm Post subject:

There are no restrictions for this engine. He is old enough to run up to KT100.

Thanks for your help. I can try to take pictures of what I am talking about if it will help.

Jeff

John Matthews · Posted: Tue Jun 28, 2011 4:35 am Post subject:

Hi Jeff,

Very familiar with the GX160, no need for pictures. If you want to run it as a kart motor you'll need to open up the side cover and remove the governor. Then you'll want to buy or fabricate a throttle hook-up with positive return spring as the stock throttle system won't work right anymore. You'll also want to install a different exhaust, and drill out the jet in the carb at a minimum. There are plenty of other things you could do but I won't get into them here.

But, let me make a suggestion here. If you have a brand new stock GX160 why not sell it to someone who needs one for a cement mixer or septic pump truck and buy a Briggs Animal?

The Honda is a fine motor, I have a modified GX200 in my showroom right now (the 160 went to the septic guy Laughing

). But, if you want a bolt on package that's built for kart racing and will let your son race local, regional and national events in the future a Briggs LO206, or World Formula will serve you much better. The motor mount, chain guard, and clutch are the same and I'm guessing you don't have a pipe yet so all the kart specific parts you've bought are fine.

Here's a link to Briggs Racing http://briggsracing.com

Let me know if you have any questions....

Cheers,
_________________
John Matthews
Heartbeat Power, LLC.

Greg Jasperson · Posted: Tue Aug 09, 2011 8:29 am Post subject:

One quick fix you can do is to add a second governor spring. The large goldish spring is the one you would add. By doing this, you will raise the governor's engagement point from 3600 to about 5800 RPM. Cheapest and quickest way to solve the problem, and you will probably never have any issues with it.

I agree that the briggs may be a better long term solution though.