GX200 engine dissassembled, now what?

[Jake272]

Hey guys working on a GX200 that came off an amusement park cart. I absolutely couldnt even get it to turn so I decided to completely dissassemble it. Reduction case was filled with water and the clutch was rusted over, rust in the cylinder but nothing in the crankcase if thats even the right term (where all the gears are). Just a bunch of gunk in the oil. Ive got it all cleaned out and nothing looks damaged to my eyes besides the stuff in the reduction case which I think I need to get rid of and figure out a different clutch/torque converter setup anyway.

So i know i need a gasket kit and probably new piston rings but is there anything else I should replace or look into while ive got it apart? Sorry this is a pretty open ended question but any help is appreciated, thanks.

 

[BaconBitRacing]

Hey guys working on a GX200 that came off an amusement park cart. I absolutely couldnt even get it to turn so I decided to completely dissassemble it. Reduction case was filled with water and the clutch was rusted over, rust in the cylinder but nothing in the crankcase if thats even the right term (where all the gears are). Just a bunch of gunk in the oil. Ive got it all cleaned out and nothing looks damaged to my eyes besides the stuff in the reduction case which I think I need to get rid of and figure out a different clutch/torque converter setup anyway.

So i know i need a gasket kit and probably new piston rings but is there anything else I should replace or look into while ive got it apart? Sorry this is a pretty open ended question but any help is appreciated, thanks.

Look into honing the cylinder, you can get one for a drill. If it was that gross then I’d hone it. Get it down to bare block (no rod or cam or valves or crank or anything) then give it a bath in warm, soapy water. Then dry completely. If you have a shop sink that will work, if not then do it while the wife is not looking… if you get my drift… kitchen sink.

 

[BrownStainRacing]

I never seen the inside of 1 with the gear reduction. got any pics???

Hey guys working on a GX200 that came off an amusement park cart. I absolutely couldnt even get it to turn so I decided to completely dissassemble it. Reduction case was filled with water and the clutch was rusted over, rust in the cylinder but nothing in the crankcase if thats even the right term (where all the gears are). Just a bunch of gunk in the oil. Ive got it all cleaned out and nothing looks damaged to my eyes besides the stuff in the reduction case which I think I need to get rid of and figure out a different clutch/torque converter setup anyway.

So i know i need a gasket kit and probably new piston rings but is there anything else I should replace or look into while ive got it apart? Sorry this is a pretty open ended question but any help is appreciated, thanks.

 

[panchothedog]

Depending on how much rust was on the cylinder and if you can get it to clean up, you might want to get a new stock piston. Normally they come with rings and are pretty inexpensive.

 

[BrownStainRacing]

Depending on how much rust was on the cylinder and if you can get it to clean up, you might want to get a new stock piston. Normally they come with rings and are pretty inexpensive.

@panchothedog
That's a good point. wouldn't want piston slap, on a freshly honed cylinder with new rings only.

I'm not 100% sure on the gx200 with gear reduction, but the regular gx200, you can use clone 196cc internal parts. They are the same bore dia & wrist pin dia. The stock dished piston kit comes with new piston, rings, wrist pin, and circlips, you can probably find them under $15. The flat top piston kit, will be around $20.

 

[Denny]

You can not get rid of the clutch gear reduction unless you are going to replace the crankshaft and engine side cover! You would be better off buying a new engine then.
That is not only a 2:1 gear reduction but also a wet centrifugal clutch. You can buy kits to rebuild them on the World Wide Web. You can even get bolt on replacement units for around $200.00 American.

 

[JimD]

Did you also get the concession kart frame? It is way too heavy and the ground clearance is not very good for any off road driving. if you got the chassis, what is the name on the concession kart chassis?? Most likely it had a timing belt drive system since those are clean and don't get any oil on the person that rents it at the track. On the timing belt rear pulley, do you see the name Pfeifer Industries?
What part of the country are you in which will give you a feel for how much abuse that engine has been through. Figure if you are in Florida or CA then it was ridden 11 months out of the year and if you are in Alaska it might have a lot less time.

As Denny pointed out I would think seriously about keeping the gearbox. All the stuff inside the gear box is metric and you will not find much to bolt on it if you toss all that stuff. The crankshaft is too short for a standard clutch so if you don't own a lathe or have a great friend that is a machinist then you will have a very long project ahead of you. But a great learning one that when you are done you will be a wealth of information.

 

[Jake272]

I'm really regretting not taking more pictures but ill post what ive got. Thanks for the suggestions guys it can be kinda overwhelming when I start thinking about too many components.

Okay I've looked at honing the cylinder, whats the better tool? The one with the three grinding rocks or the weird spiky ball one? And do I need to wash before or after?

Name on the plaque is johnson kart J75 manufactured in 96. I'll have to check on the rear timing belt pulley manufacturer. I'm in Kansas so it would have had atleast some downtime in the winters.

I don't have any issue with keeping the gearbox I was just having trouble finding anyone talking about it, and after opening it up and watching the water pour out I assumed it would have to be completely replaced at great cost anyway, but if I can replace the clutch that seems more feasible.

Lemme know what you guys think I should be replacing, ordered the engine/carb gaskets going to look into replacing all the bearings as well. I'll hold off on the honing tool and piston rings/piston for now, but I dont remember feeling anything messed up on the piston but I didnt give it a very good inspection, should I be looking for cracks?

Thanks again please ask as many questions as you want this is helping immensely.

 

[panchothedog]

I know that pictures can be a little deceiving, BUT from the looks of the inside of your cylinder as well as the shot of what looks to be exhaust port I think you have a custom shaped boat anchor. Could it be bored and a oversized piston found to fit it, probably. For the head I'm sure it would be much cheaper to buy
a new one as compared to rebuilding that one. I would suggest you buy a new engine, except as mentioned by JimD you probably need the 2 to 1 reduction box to move those very heavy looking karts. Are you trying to do a restoration
project with them, or are they of some sentimental value to you. Just wondering, as they don't look very fast or practical. Suited for a paved rental
track as originally manufactured. Hate to sound so negative. And I am not trying to be a giant downer. But you have your work cut out for you getting that
engine back in running condition. I guess it comes down to how bad you want
that one.

 

[Denny]

A dingle ball hone is best for used cylinders. That cylinder looks like it is going to be really pitted up. Not a good thing. If it was my engine I would be looking to have it bored out with a new oversized piston and rings. Rebuild the wet clutch also and replace all bearings. Pay very close attention when you take it all apart! Make sure shims and spacers end up back in the proper spots.

 

[JimD]

Johnson Karts is out Milwaukee, WI. Depends now on what you are going to do with the karts. Since I see a crawler in the picture you could build a track but I figure you got enough projects going. The kart with the present tires is meant for slow speed maxing out at less than 20mph. It is way too heavy for back yard fun driving unless you stay on the road and that depends on the amount of traffic and the men and woman in blue that may frown on you using the road. It did have a Pfeifer belt drive system on it since my son makes and sells them to the concessions kart manufacturers. They are not very good if you have gravel roads that you will be driving on. I definitely would change that over to chain drive going to the axle, #41 (#420 is the same as the #41) or #40.

 

[BaconBitRacing]

Unfortunately I’ll have to agree with @panchothedog, it would have to be overbored, honing couldn’t get that smooth. Here’s some pictures of a Clinton I disassembled yesterday. This is a honable cylinder.and we aren’t trying to be downers, locked up engines just aren’t worth it sometimes.

 

[Jake272]

Yikes I was worried you guys might say something like that. First off, what do you mean by custom boat anchor? I had already looked into getting a new engine seeing how rough the gx200 looked but if this entire frame is going to be too heavy maybe I should start looking for something else. I have no sentimental value on these karts my buddy and I bought them $125 a piece at the junk yard but I had kinda hoped I could chop as much weight off as possible and make them somewhat suitable for gravel with some work. I do have a small welder but no lathe or machining experience.

And no I really appreciate the honesty better to hear it straight then put a bunch of money for what is rapidly becoming a lost cause.

 

[BaconBitRacing]

Yikes I was worried you guys might say something like that. First off, what do you mean by custom boat anchor? I had already looked into getting a new engine seeing how rough the gx200 looked but if this entire frame is going to be too heavy maybe I should start looking for something else. I have no sentimental value on these karts my buddy and I bought them $125 a piece at the junk yard but I had kinda hoped I could chop as much weight off as possible and make them somewhat suitable for gravel with some work. I do have a small welder but no lathe or machining experience.

And no I really appreciate the honesty better to hear it straight then put a bunch of money for what is rapidly becoming a lost cause.

Custom boat anchor, giant paper weight, scrap metal, all the same. You might have gotten some good parts from the engine, maybe an exhaust or something, I’d pick up a cheap frame of good design and quality and build that.

 

[Denny]

That frame is built like a Mack truck! Don’t go giving up on it yet! We can help you make it usable with a simple engine and rear axle swap!

 

[Thepartsguy]

I don’t mean to be the bearer of bad news. But that cylinder would shine up with a bit of two stroke and a dingle ball. Edit: I didn’t have a hone when I cleaned up the k181 just sand paper busted two of the flywheel fins unlocking the stuck piston from the bore and sent it with a new head gasket. It’s been years and also been on two different karts. I can go out to the streaker flick the key fly down to the four way and spin donuts until I run out of gas.

 

[BaconBitRacing]

I don’t mean to be the bearer of bad news. But that cylinder would shine up with a bit of two stroke and a dingle ball. Edit: I didn’t have a hone when I cleaned up the k181 just sand paper busted two of the flywheel fins unlocking the stuck piston from the bore and sent it with a new head gasket. It’s been years and also been on two different karts. I can go out to the streaker flick the key fly down to the four way and spin donuts until I run out of gas. View attachment 137527View attachment 137528View attachment 137529

Well you have more experience than I do, that cylinder just looks much more pitted that yours was. That Kohler cleaned up nice!

 

[Denny]

Just because it runs don’t make it right.

 

[Thepartsguy]

Just because it runs don’t make it right.

it was a $20 kohler with e-start and a beefy 15 amp Charging system. for $20 it doesn’t have to be right at all... it has to run for years to come like it has ran for years in the past. anyway Op just get a new engine. that way you don’t have to tinker.

 

[BaconBitRacing]

it was a $20 kohler with e-start and a beefy 15 amp Charging system. for $20 it doesn’t have to be right at all... it has to run for years to come like it has ran for years in the past. anyway Op just get a new engine. that way you don’t have to tinker.

We know you love tinkering!