Who'd-a-thunk (clunk)

[mandoman]

I'm beside my self, LMAO... ok my work horse.. ezgo st 350 robins.. cranks with a little choke... push it off and go,,, starts with ease... purrs like a kitten... wont pull the hills...Hmmmm.. so shorter belt... yes will pull the hills.. will gear down will reach top speed, will drive with spirit on level ground.... ON ONE CYLINDER..... I finally did the first thing you guys suggested .... last, hmmm (must be a hard nut) no compression, on one cylinder... heck the piston isnt moving...... occasionally I hear a clunk where the crank might be slightly tapping the rod or something... I feel pretty dumb about now. Sooooooo I'm getting ready to pull this puppy down, I want to do it as inexpensive as possible. A couple questions. 1. Should I pull the motor from the buggy? 2. How hard is it to replace a connecting rod? Thanks in advance! God Bless!

[G2Rebel]

Yes pull the motor, it is really the easiest way. 2. connecting rod is easy to replace but that may not be all you need at this point. Check to make sure the crank is not marred or scarred or gouged. 9 times out of 10 it's the clutch side that breaks. Also make sure your valves are ok.

[mandoman]

Indeed, I'm hoping to make it a pretty quick turn-around. I guess the point is, I know the 350 cc Robin is a great little engine, but before I put too much money into it I would rather convert it over to a v-twin, the motor is really all I need the brackets ect will be a piece of cake for me. I just dont have the extra money for the conversion. With that said I'm thinking the conversion is in " Tug-tugs " future, so all I wish to do is get it back usable, at this point in time. Thank you for your reply. God Bless P.S. it is the clutch side that is smashing the plug. Can you tell me, is there any thing, when I break it down to look at that may not be obvious?

[mandoman]

That is other than you have already suggested. Thank you again BTW God Bless.

[G2Rebel]

Also make sure the gears on the crank and balancer are in good condition. Make sure when you pull it down to clean all the metal out of the block and the oil pump. Also in case you didn't already know there are no bearings on the connecting rods in an EZ GO.

[mandoman]

G2, Thank you. No Bearings?? so that leaves NO options for the crank....so if my crank is scarred I may be S.O.L. and does it also mean if I get a rod from my local ezgo dealer that it will be machined to the correct dia, with out lapping or honing? Would the journals on a 295 and 350 cc be the same? interesting, I guess I should break down and order a rebuild manual. God Bless.

[jaytee50]

Originally Posted by mandoman

G2, Thank you. No Bearings?? so that leaves NO options for the crank....so if my crank is scarred I may be S.O.L. and does it also mean if I get a rod from my local ezgo dealer that it will be machined to the correct dia, with out lapping or honing? Would the journals on a 295 and 350 cc be the same? interesting, I guess I should break down and order a rebuild manual. God Bless.

my outboard had a severely marred bearing surface on the crankshaft....
i used fine grit (600?) sandpaper, with a little oil on it and restored the shaft surface. i also did the same to a severely pitted piston in the same engine.

results: the boat still runs today about 300hours on it since.

engines can be forgiving, if you just make sure you clean every part in a parts washer after.

which means i recommend you tear it down completely, checking each part....obviously the first thing to do is pull the engine and spread out some cardboard or a sheet to catch all your screws and nuts.

[DOOmsman]

Also mark alignment points as you disassemble.

[mandoman]

Good point Doomsman, Jaytee very interesting, I can do this, I have the tools and the skill. If Im only bringing down the high marks (mushroomed areas if you will) then I would really not take much off the journal surface. Do you guys know or know if there is a thread here that will give you the HAPPY clearance for the bearing surfaces? I thought about just making a rod, I think I have some aluminum that will work but my milling machine is sick and for eighty bucks, if something isnt right Iwill not have to wonder if it was my part or not. Do you know if the rods them selfs are balanced, I know they do the crank. God bless!

[mandoman]

Quick update,
I pulled the robin apart to see if it was going to be economical enough to fix her. As it turns out the rod was broken busted up some of the piston skirt. A dealer bout 20 miles away had the parts and after bout 35hrs of the unyielding crank and cleaning parts + $116, the little engine was on its way to huffing and puffing again. Put it all back together (no extra parts or screws) choked it twice yesterday , and she has been running ever since. Ive had close to 1k lbs on it climbing 20 deg hills, cant ask for more than that. My buddy who helped me set the engine in said, " you look happier than a mule in a briar patch" what ever that means, I guess the mule was indeed happy, I couldnt have hoped for a better outcome..... Thanks for all your help! Now that it is running well, I have another issue. Is there some adjustment that will let you regulate the low speed of the cart, what I mean is, when I hit the gas it kinda lunges forward, with what im doing I would like to just slowly creep around sometimes. I move the pedal probably bout an inch, if I hold it there eventually it will almost hit top speed, so it seems very touchy, as I try to creep, it jerks which bounces my foot on the pedal, in turn lunges the cart , and the vicious cycle has started, thanks for your help, thank you in advance for your future help. God Bless.