EZGO Workhorse / Jacobsen Build

[slonomo]

Never a good thing when you find this.....

[slonomo]

Going to continue tearing this engine down for inspection. I'm guessing full rebuild. Any sources for parts? I'm also considering buying a rebuilt engine from Georgia, anyone ever use those guys down there?

[slonomo]

Definitely not good

You Tube

You Tube

[trig123]

Originally Posted by slonomo

Going to continue tearing this engine down for inspection. I'm guessing full rebuild. Any sources for parts? I'm also considering buying a rebuilt engine from Georgia, anyone ever use those guys down there?

Yes, they are top notch. Give them a call.

[slonomo]

The clutch side connecting rod came apart. The good news is the block and both cylinders are clean with no visible damage. Thinking I can rebuild this engine.

[slonomo]

Heads look good. Valves are tight. Cam and rockers look clean. I'm not sure on the crank, it looks like aluminum buildup on the journal for the damaged rod, that might clean up ok. The piston measures 2 5/8" but I'm sure its a metric size, so not sure if this is overbored or not. Anyone know the spec on piston size for the 350cc?

[JPonLKN]

Robbin engine manual.pdf
Lets see if this works. Engine manual for that motor. Should have all the specs you need. Pay attention to the crank journal diameters...if the damage from the rod, or father time left it too small, you will lose oil pressure and it will detonate again. Ask me how I know. You can do a full rebuild, it will run great for 15 minutes...and that is about it.

Look at your broken con rod parts...see if both bolts are still in the rod, or if one came loose. I can see one bolt is fully seated, just can't see the other. If it came loose, that would be the reason for the detonation.

[slonomo]

Originally Posted by JPonLKN

Attachment 211796
Lets see if this works. Engine manual for that motor. Should have all the specs you need. Pay attention to the crank journal diameters...if the damage from the rod, or father time left it too small, you will lose oil pressure and it will detonate again. Ask me how I know. You can do a full rebuild, it will run great for 15 minutes...and that is about it.

Look at your broken con rod parts...see if both bolts are still in the rod, or if one came loose. I can see one bolt is fully seated, just can't see the other. If it came loose, that would be the reason for the detonation.

Thank you!

It appears that both bolts are seated, not sure if they are still tight. The other piston/con rod is perfectly fine.

One thing to note. It looked like that oil hadn't been changed in a long time. The amount of dirt and grime build up on the oil filter bolts and flange tells me that no one had touched that thing in quite a while. Just me using the 10mm socket on it knocked a serious amount of dirt off. At first I couldn't even tell there were bolts there. I'm guessing this lack of maintenance had something to do with the carnage.

I did see a nice pool of oil in the head under the valve cover, and all the rockers had oil on them. The oil was not sludged up and no dirt or debris was present up top.

[JPonLKN]

Detonation from something other than a loose conrod bolt...if that bolt was loose, it would have come out almost entirely. Considering it wasn't a bolt, I would pay close attention to verifying spec on the crank journals...and making sure the passage in the crank is clear, oil pump is in good shape, etc. Was the governor spring on top of the differential pulled all the way in? I guess at this point, it doesn't matter what the cause is...just go through the rebuild in the manual, and you should be good. I would do the clean up and spec verification on all the parts before you order anything. That crank alone is over $300 if you need to find one. A full rebuild kit minus the crank is also over $300. By the time you get there, you can get a rebuilt one from M&M in Augusta...although I am not sure how they would accept a broken down motor. Might be added cost for bad components that they can't rehab and reuse.

[slonomo]

Originally Posted by JPonLKN

That crank alone is over $300 if you need to find one. A full rebuild kit minus the crank is also over $300. By the time you get there, you can get a rebuilt one from M&M in Augusta...although I am not sure how they would accept a broken down motor. Might be added cost for bad components that they can't rehab and reuse.

Funny you mentioned cost. I just called M&M and explained the situation. The gal said it should be ok as long as there's no damage to the block or balancer. Its amazing that everything else looks really good in there, so that's encouraging. She said a new crank from ezgo is $325 so if the journals are out of spec that would be extra. Rebuild is $700. Shipping both ways is $80. She will send me the proper box and shipping label for free. So worst case for a rebuilt is $1105.00 plus tax. It would cost me $600 plus to rebuild myself, and I don't have a dial bore gage or any machining capability. If I wanted to put a clone in, that's easily $700 with clutch and engine, over $100 with mount etc.

So, looks like I need to do some thinking. Having a factory setup on this cart is appealing. I already have a Vtwin monster cart lol