Newbie Questions

[jmrozier]

I have an EZGO 94 GX444 4-cycle Gas Marathon with a Robin EH29C engine. The engine runs but smokes a lot and the air filter is full of oil. Last weekend we dropped the whole drive assembly out so we could get to the engine. The engine has virtually no compression as I can easily turn the engine by the centrifugal clutch.

Questions:
1. It has a Comet Duster clutch, what is the best way to remove it? When searching the web, I have seen what looks like a long rod with a hex head on it, and also posts about using a piece of 5/8” rebar and a 3/4” fine thread bolt, but it is not obvious to me how these tools are used on my clutch.
2. How hard is it for a couple of people that have a fair amount of mechanical ability to do the needed repairs/rebuild?

I don't have a lot of money to spend on this project so I need to do it the most cost effective way. Any help is greatly appreciated.

[dwon5]

the repairs are not that hard. you have 5 posts so you can get into the manual section now that should have everything you need. I do mostly electrics so I can't answer the clutch problem but some body will

[dougmcp]

Here is all the info I have on the 94C Duster clutch, does this help at all?

[jmrozier]

I got the clutch off today using a 9/16-20 x 2" Grade 8 bolt and a piece of steel rod that would just fit into the hole. I cut the rod about 1" shorter than the depth of the hole and it worked perfectly.

Now I have to get my hands on a 30mm socket to take the flywheel off so I can finish disassembling the engine.

Thanks for the info on the Duster clutch. It will come in handy when I finally get that far in this project.

[dougmcp]

Good to hear you got the clutch off.
The complete E29C rebuild manual is here: EH29C EH35C Engine Rebuild Book

[jmrozier]

Thanks dougmcp. I got the manual the other day & printed most of it - until my printer started having problems.

The engine is out sitting on my workbench. I have not opened the crankcase, because I don't have a 30mm socket to get the flywheel off. I anticipate getting one today.

The pistons look like they are OK, except for all the carbon and the fact that they move a lot from side to side (rings). The cylinder walls are smooth and there is no ridge at the top. I will know more when I get the bottom disassembled.

Where is the best place to take it to get the wear checked and the machining work done if that is required? Do machine shops that work on car & truck engines also work on small engines - or do I need to find a shop that specializes in small engines?

[dougmcp]

I'm not a gas cart guy but I know that you can get 0.25mm and 0.50mm oversized pistons and rings for them.
I would think that any machine shop capable of boring should be able to do any size. Depending on the wear/taper, you may even get away with a simple honing.

[jmrozier]

The motor is just a pile of parts now. The rod bearings and the crank journals look pretty good but I want to have everything checked to make sure there is not excessive wear anywhere. It would also be good to know if the pistons are stock or over sized before I spend the money on a rebuild kit.

I have been looking around this small town in East Texas and nobody even knows someone who can or will do the machining. There are some places that I know of in Dallas (100 miles), but was trying to get it done locally. Well, it is off to Dallas next week. ;-{

[jmrozier]

I bought 5 gallon of "parts cleaning solvent" which turns out to be just naphtha, which I am using to get the major dirt and crud off of everything. Is there a cleaner/solvent that will clean off all the discoloration and bring back a new like finish to it?

[Gimpy]

If you are that far into the engine you should consider purchasing a 6" digital caliper; Harbor Freight has an acceptable one for $16.99 (Item #47257). It is NOT accurate enough to make critical measurements on say, crankshaft bearing clearance but it is accurate enough to help you make decisions on oversize pistons, if the crank is out of tolerance and so forth.
Many of the auto parts stores have 'free loaner' tools; perhaps you can get a bore gage to check your cylinders.
If the pistons easily move side to side within the cylinder it is almost certain that you will need oversize pistons and the cylinders bored to match.
Be careful when you disassemble; things such as connecting rod end caps are matched so be careful not to swap them.
This stuff is fun so enjoy yourself. If it is your first time it will be quite the learning experience.

[Michael Eddie]

Wow im surprised I missed this thread, but those picture are bringing back great memories of engine builds!