Honda G200 Project

So as some of you know I recently aquired a neat old Honda G200 engine in pieces:







Never worked with one before but this one seems pretty cool so far. Has some pretty cool features like ball bearings for the crank, aluminum cam lobes and gear, governor built into the cam, etc.





It's breaker points ignition with the points, condenser, and coil under the flywheel:



I'm gonna try and rebuild it without buying any new parts as it's in fairly good condition. Might do a couple of performance mods along the way and make into some mild mod go-kart engine or whatever.

First minor mod I did was shave some material away from between the valves and the cylinder, hopefully to allow for easier flow:





Not sure if it will really help but it sure won't hinder anything, haha.
So I plan to do some more minor stuff like that, should be fun to mess with. Let ne know what ya think!

Interesting flat head there.  I've never seen a Honda like that before.  Should make a great motor for a mow-kart.

Yeah it's definitely a pretty cool little unit.

What’s the factory power output of one of these, 5 horse?

In the pic it looks almost as big as the yellow Kohler

Yep, rated for 5hp max. Also sonce you mentioned it I figured I might as well do a size comparison:



So yeah it's pretty close in size to the small block Kohler, haha.

Just for comparison, what’s that Kohler rated at?

The Kohler is rated for 8hp and has approximately 18 cubic inches of displacement. The Honda is 5hp with approximately 12 cubic iches of displacement.

Interesting engine. Looks to be around 80's ish. Cool comparison too, to the Kohler. Size of the Kohler is just a little bigger, and get you 3 more hp.

Nice little engine, I've got a G300, which is the 7hp version. There should be a date of manufacture stamped onto the block somewhere. My G300 says it's 1977, so I'd say yours is in that age bracket. Any plans to build a performance exhaust/air filter?

Thanks fellas. Yeah I'm thinking it's late 70's early 80's. I do plan on making a custom and exhaust and probably a custom air intake setup as well.

Speaking of which, I was finally able to remove my muffler from the engine today:



Tried some heat on the nut as they were both siezed pretty bad. Not really sure if it helped but I eventually got them both off, haha.



The exhaust port was pretty dirty so I cleaned them both up a bit and did some mild porting:









Should be a bit better.

The exhaust port definitely needed that.

Yeah for sure, definitely glad I was able to get the muffler off to check it. Also now I can make up a cool header pipe! Hahaha.

I see Honda has been preferential to their stud design rather than the Briggs or Kohler bolt or screw design for a long time, that's cool. Does it have a similar carb to a GX160? They're both about the same HP. Pretty neat engine.

The studs do make it a bit hard to get the die grinder in there though.

The carb looks similar to the ones on the OHV engines to me, but I don't know my Hondas very well.

The carb:





Anyways I got my valve train all put back together, figured I was pretty much done with that part of it:





Valves seem to seat nice and the valve guides are nice and tight, so that's good to know. After that I half assembled it enough to be able to rip the flywheel over and check for spark. There wasn't any, haha. So I'm most likely gonna have to be checking into the coil and condenser. Not too big of a deal, just glad that I checked before I got it all put back together. Haha.

You can take the studs out using vice grips on the shank. The G series carbs are pretty similar to the GX range, the choke and throttle 'levers' are different though.

Oh okay. I kinda figured they would turn out, but I wasn't positive and I didn't wanna break 'em off or something. Haha.

all the carbon build up makes me think either it's a high hour engine they ran cheap gas or other "stuff" through it or maybe it saw some two stroke mix fuel here and there hopefully it's not like the last briggs had ran like a top smoked like train.

Yeah, well it has been in service since the late 70's or early 80's, so I can see how there would be some deposits in the exhause port.

If you're gonna take those studs out, lock two nuts together on them and use that to turn them out with a wrench. Lot less sketchy than vise grips.

Nah I don't have a reason to take them out now. That trick does work good though. That's what I did when I put the head studs in my K321, haha.

I'd probably run a die down those exhaust threads to clean them up. But that is totally up to you!

Yeah that wouldn't be a bad idea. I already attacked them with a wire brush, but a die would really do the job, haha.

Well I dove back into the ignition setup on the ol Honda tonight, and since I couldn't find anything out of the ordinary I tried a few small things that still didn't fix the no spark issue. Then I gave the points contacts a real good cleaning with a flat file, threw the flywheel back on and ta-da!



A nice bright blue snappy spark! Very happy about that, one less thing stopping me from getting it running, and I didn't even have to buy any new parts!

After that I just installed the piston on the rod and called it a night:



Making a little more progress, haha.

Nice! You gotta find gaskets for it now?

Thanks Rich. Yeah I think I just need a new head gasket and a crankcase cover gasket. Maybe one for between the carb and the block too.