Robin MCI 350 crankshaft installation and rebuild question(s)

[Tfastle@aol.com]

I got my hands on a 2007 EZGO MPT 1200 with the Robins MCI 350 engine completely disassembled, dirty and rusty. Long story and a lot of work but I now have the parts completely cleaned up and have ordered the pistons, rods, valve guide seals, gaskets, bearings, timing belt and the other misc parts I need to reassemble. I do have the manual for it and, while everything is not completely clear, I would say it's pretty good. I do have a few questions for anyone that has completely gone through one of these engines and is willing to share their thoughts.

I am fairly confident I have or will have soon (when my ordered parts arrive) all of the parts for the engine with the exception of one - the crankshaft spacer. In the book is shows a thin spacer on the fan end of the crankshaft that goes on before the crank is inserted into the bearing on that end (the block end that bolts on). It's called "spacer, crankshaft." In the parts list there is 4 different part numbers for it. They are a range of sizes, in .2mm increments, from .6mm to 1.2mm thick. Does anyone know were to get them? I've looked high and low and have not be able to find them so will likely have a machine shop make me one (or some). My bigger question is with regard to assembly. Clearly it's not a one size fits all and may end up being a trial and error approach. I am guessing that with too thick a spacer the crank probably bind some. Anyone have any input oh how best to approach this? At .6 mm the thinnest one is about .024" and at 1.2 mm the thickest one is about .0047 so they are all pretty darn thin. How critical is this? Do I need to get one of each made and find the one that binds a bit and then use the one that is the next size smaller? Also, when putting the crankshaft into the block, is the best way to put the 4 bearings into the block and block end first and the second bearing that goes on the crankshaft clutch side (next to the bearing in the block) on the crankshaft itself and carefully tap the block end into place and then tighten the bolts? Or, is there a better way to do this? Let's say I need to try a different size spacer. Is it difficult to get the block end off or not too bad? I've split the cases my fair share of times on motorcycles once pulled back together they are not easy to re-split. Hope that's not the case with this.

Any input from someone with some experience with this would be appreciated.

Thanks in advance.

[trig123]

I think I got a spacer at my shop. I will get back with more information later today.

[Tfastle@aol.com]

Wow, that would be great. Please let me know.

If it helps, extrapolating from the spacer on the bal. shaft and based on the OD of the crank where it goes my guess is it would be something like the following dimensions:

35.5mm (1.398") - ID
53.125mm (2.093") - OD (this is a bit of a guess)
.6mm or .8mm or 1mm or 1.2mm - Thick

Thanks!

[trig123]

I found the crankshaft but spacer is missing. It must have fell off somewhere. I will look more later today as I have more than one I think.

[Tfastle@aol.com]

Ok, mucho thanks for looking. I'll keep checking back.

[trig123]

If I can't find a spacer you can still buy them.

Just google this
Part # 26685G01. You will see a dealer that has these. Country Cat shows up when I search as the dealer.

They are all in stock except the smallest one.

I will look again tomorrow and see what I find. I got busy today and didn't have much time.

The bearings should be a press fit in case and end cover.
Do you have the engine manual ? It shows everything you need to know.

[Tfastle@aol.com]

Thanks for the info Trig. I had looked at CC before and when I ordered it ended up being back ordered. I tried again today and one of the 4 sizes took the order, one was not available and 2 were special orders. I ordered the one that was not back ordered (26685G01 .8mm). Hopefully they do have it and it will ship.

I do have the manual and had read through the installation of the crank, bal. shaft and block end case but apparently too quickly and not very well. I just reread it and see how it works. Via the space measurements described in the manual I should be able to calculate what spacer I need thus eliminating the trial and error I mentioned in my original post on the subject. At that point, if I need a different spacer I can try special ordering the one the measurements would dictate.

I will let you know if I am able to get the spacer or not. As I get this back together I am sure I will have other posts with other points of confusion.

Thanks very much for your input!

ps - Lordy lordy, just checked my email and CountryCat says my order has shipped. My doubts not with standing, maybe I'll get a spacer after all!

[trig123]

Originally Posted by Tfastle@aol.com

Thanks for the info Trig. I had looked at CC before and when I ordered it ended up being back ordered. I tried again today and one of the 4 sizes took the order, one was not available and 2 were special orders. I ordered the one that was not back ordered (26685G01 .8mm). Hopefully they do have it and it will ship.

I do have the manual and had read through the installation of the crank, bal. shaft and block end case but apparently too quickly and not very well. I just reread it and see how it works. Via the space measurements described in the manual I should be able to calculate what spacer I need thus eliminating the trial and error I mentioned in my original post on the subject. At that point, if I need a different spacer I can try special ordering the one the measurements would dictate.

I will let you know if I am able to get the spacer or not. As I get this back together I am sure I will have other posts with other points of confusion.

Thanks very much for your input!

ps - Lordy lordy, just checked my email and CountryCat says my order has shipped. My doubts not with standing, maybe I'll get a spacer after all!

You welcome. Glad you could get it ordered. Please keep us updated on your engine build if the spacer is the one you need. Good luck

[dirtyyoda77]

Ive searched high and low for those spacers for a engine I was putting together

Country Cat had what I needed like trig said

[Tfastle@aol.com]

Here is a brief update.

Received the spacer from CC and, after having installed the crankshaft and bal. shaft and measuring the clearances as per the manual it looks like it will work. Thanks Trig.
Now I have to figure out the rings. Am going to do a new post with that question since it likely won't get seen here. Thanks to everyone that replied.