My Lawnmower Forum banner
1 - 2 of 2 Posts

·
Registered
Joined
·
28 Posts
Discussion Starter · #1 ·
I have a litttle Craftsman M250 with a Honda GCV160 on it. I like to tinker with stuff and was wondering what I can do to my little push-mower (besides removing the governor and using a ligher blade). I am particularly interested in parts interchangability between Honda engines.

I am wondering if it is possible to replace the carb on a GCV160 with the carb from a GCV190, and what might be required to do so? Are there separate model carbs for the Automatic Choke System? Do you actually think there any possible benefit from running the slightly larger carb on the smaller motor? Has anyone messed with adding a velocity stack in place of the air filter?

I thought about trying to install the '190 muffler on my '160, but I am pretty sure the mufflers are the same between GCV160 and GCV190. I might actually put together a little exhaust pipe... stepped primary exhaust stack with the little tractor flap thingy on it. Lol. I am not sure how accurate the formulas are for small engines, but I found some equations for optimal exhaust diameter. The equations I found did not tell optimal length, though, sadly. For swept volume at 2500rpms we are looking at ~0.675" ID exhaust, and at 3500rpms it's closer to 0.795" ID exhaust. Stainless schedule 10S 1/2" is 0.674" ID, and 10S 3/4" is 0.884" ID... which should fit over the outside of the 1/2". Close enough for stupid push-mower modifications... I do not have a lawnmower engine dyno to test the effectiveness of any of this.

Anyone know if the cam wheel from the '190 can be installed in the '160? Belt lengths/sprocket size/tooth count being the same [or similar enough]? I got as far as seeing that they are, in fact, separate part numbers between the '160 and '190 cam wheels.
 

·
Registered
Joined
·
193 Posts
I have a litttle Craftsman M250 with a Honda GCV160 on it. I like to tinker with stuff and was wondering what I can do to my little push-mower (besides removing the governor and using a ligher blade).
You don't want to do this. You would reduce the flywheel moment of inertia. You want that to be maximized in a mower. A lawn mower engine having a lightweight top rotor of low polar inertia drives a rotary blade having sufficient inertia to provide the major flywheel effect for the engine.

You want that blade running the same speed all the time (not speeding up and slowing down), just like a generator but for a different reason. That's the governor's job. A mower is all about maintaining force to cut grass continuously and cleanly.

The timing is optimized for the max RPM which is where the work occurs. You can gain a little power with a fatter main jet, but you can't go more than a few sizes up without messing up the stoichiometry. Honda jets are numbered by the aperture diameter in hundredths of a mm. So for an example, a GCV160 #62 jet is part 99101-124-0620 = 0.620mm = 0.0244"
 
1 - 2 of 2 Posts
Top