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Discussion Starter #1
Hey all, I’ve posted on here a few times about a CL350 I purchased that was supposed to be “fully rebuilt”.

Turns out the previous owner was not as good of a mechanic as he thought. Head gasket leaking (spray wd-40 at the block/head seam and engine dies almost immediately) when engine is warm (dies at idle) and at high rev (engine loses all power after 6,000rpm).

Also found some missing bolts on the bike and engine, so I figure if all of these little things are messed up, god knows what else is lurking.

Setting this post up to be an ongoing update thread.

Progress so far is engine, carbs and air filters are off the bike, as well as the rear rack and silly after market cruiser pegs the p/o put on.

So far I know at least the following needs to be done:

- replace head gasket (and check block/head for smoothness (right word?) before putting a new one in).
- replace cam chain tensioner with aftermarket part (I’ve read that these are notorious for failing)
- replace all other engine gaskets and clean and grease/lube all engine parts per FSM
- Rebuild and check jetting on carbs
- Replace air filters (do they need it? See photos attached)
- Clean and coat gas tank (it’s not fully rusted, but there are rust spots)
- Clean or Replace petcock (I haven’t traced this yet, but when draining the tank there was no fuel flow out of the right side line)
- Replace electrical - regulator/rectifier, condensers, coils , plugs.

These are just to get the bike running well again... never mind brakes, checking all bolt torques and replacing shocks, maintaining forms, etc...

I know this is a broad question, but any big pitfalls to look out for? I’m confident with my hands (my father was a car mechanic, I worked in his shop when I was a kid), but have never rebuilt an engine before.

Looking forward to having a good winter project in front of me!

-Ed
 

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Ed, I moved your post to the Project Logs section.

The cam chain tensioner is not notorious for failing unless general maintenance on the bike over the years is sorely lacking. If the cam chain is kept properly tensioned, the rubber rollers (wearout items in question) in the tensioner and center position of the cam chain run will last a decent amount of time, but not 45 to 50 years anyway as the rubber gets hard (especially during long periods of sitting in a shed or garage not running) and will being to come apart once usage begins. Anytime you tear down one of these engines, it's a given to replace all gaskets and check all surfaces for condition, as well as replace any parts of unknown age like cam chain, tensioner and center roller, along with whatever else necessary upon inspection. If you plan to keep the bike for the foreseeable future, plan to take the head apart and check (or have a machinist check) the valves, guides and seats and of course, get the pistons and cylinders measured and checked for roundness and taper. What might be more notorious on the 350 is the cam and rockers... you might find pitted lobes and/or rocker arms, but unless they are beyond cleanup, you can send them to Delta Camshaft in Tacoma, WA to be refinished for a reasonable price.
 

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Discussion Starter #4
Thank you both for the feedback, and thanks Ancientdad for moving this to the right spot. I swear I’ll get the hang of these forums one day.

The bike sat in a garage for ~40 years before the p/o bought it... and I’m not sure what the p/o considers “rebuilt” anymore. We’ll see when it’s open.

I’ll definitely keep close attention to the camshaft and rockers, thank you for the pointer.

And yes, I’ll look into that checklist as well, much appreciated.
 

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Discussion Starter #5
Hey all,

I've set up at a community garage in the area, currently still in "tear down" phase, but approaching "rebuild" very quickly. I went all the way through to the crankcase because I found metal shavings in the engine (both glitter size flecks and occasional shavings). Thankfully the bike has only run about 60 miles since the last rebuild.

I understood that there was a need for a head gasket replacement from the mechanic I brought it to, and in going through the engine found a few reasons why that could be:

IMG_1428.JPG


If you'll look closely, you'll see that the bolt running into the block is missing, not entirely actually, just sheared off (see top of photo):

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This, along with a crack in the head (see top left of following photo) seem to be the reason for the head gasket issue. The cap nuts on the studs ranged from "tightened down with the mighty hammer of thor" and "1/4 past hand tight" so I am assuming the PO did not use his torque wrench reliably when re-installing.

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The head has been shipped off to Jim McMahon at Heads First in Westville Indiana. His praises were sung on these forums, and his thoroughness in questioning the condition of the bike was encouraging. Resurfacing of head gasket mating surface on block and head, valve seats, (hopefully not) new valves, and checking piston/cylinder dims all in the works.

Other parts to be replaced include the air filters and cam chain roller, filters seem to be gunked out beyond saving, and the roller was pretty torn up when I took the engine apart.

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When taking the engine apart, I kept on finding this blue plasticky gunk all over the studs, particularly the two corner studs that are different from the rest on the engine. Does anyone know what this could be? And besides this, the two studs that are supposed to be different, all look the same, no "hump" (I'm not sure what else to call it) as indicated in the FSM parts fiche (part 4 in the image, as opposed to part 3). Any guidance?

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Working further down the case all seems to be in order, but I cannot for the life of me get the gear shift forks to mate back up with the transmission - is there a magic trick to this? The factory service manual is very silent on the issue.

Just want to end off saying this forum has been a fantastic resource, much appreciated for all the help I've been able to pick up on here, just as a lurker.
 

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Sensei
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Turn engine up-side down and install shafts onto forks and into upper case half... make sure you align bearing knock pins and half circlips if required........
 

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To expand on Steve's post, if you're having issues, install trans without pins in the shift forks. Then rotate the drum so the channels line up with your pin holes. Then remove the shafts and put the pins and clips in the forks and reinstall shafts.
 

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Discussion Starter #10
Ancientdad - thanks for that, saved me ordering new studs.

Next up - any idea if there is a special tool that needs to be used when removing/installing the set rings on the transmission? I've mangled two of these using a normal snap ring tool.

There are three or four of these on the transmission. They do not have pins for a regular snap ring tool to mate into, just this angled groove.

304281
 

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First, let's define "set ring" to differentiate them from "snap rings". A set ring is the half-circle ring (looks like half a piston ring) that sits in the groove in the upper case to locate the large outer races of the ball bearings on the transmission shafts opposite the embedded locating pins that center the smaller needle bearing races on the other ends of the trans shafts. The snap ring above is used on the shafts themselves to hold gears in position and on some models, used on the mainshaft in the clutch basket, and even a similar one on the shift shaft of the DOHC 450 under the front sprocket cover (though that one has the typical holes in the tabs). While the snap rings you show are a little more difficult to work with, you just have to find a pair of snap ring pliers that work properly. Maybe take one with you to the auto parts store or tool truck and ask them what snap ring pliers would be best for it
 

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Discussion Starter #13
Thank you both - CMSNL refers to them as a set ring (they also refer to the upper case rings noted by ancientdad as the same), but they are of course a snap ring, less the holes in the tabs.

Many thanks Jim - I'll be picking a set up this weekend.
 

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Discussion Starter #14
Hey All,

Thanks to your help - the transmission and kickstarter are back in the case, and the case is fully re-assembled. I'm now getting hung up on the gear shift mechanism, namely this small part labeled "7" on the fiche, and its associated spring, "9".

I've tried scouring the internet for a video or an image of how this thing goes back together (I managed to forget to take a picture of what it all looked like with the clutch basket off), but so far all of the videos I've found have part number "7-1" installed.

I can't for the life of me figure out where this part and spring go to... any guidance?

305291
 

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One end of 7 goes into 18 and the other end into 11.
In the case there is a little hole. The spring should have a little finger sticking out. The spring finger will go into the case hole. Then wrap around/insert the spring into the finger of 7.
 

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Discussion Starter #17
Thanks - and now looking closer at the factory service manual they actually do have a nice diagram. Apologies for the added post.

Is there a torque spec for the neutral stopper (The bolt that holds the little ball inside the indent when the transmission is in neutral)? Or should just be bottomed out, snug, etc?
 

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I don't know if there is a torque spec, but since it's just a spring-loaded detent ball in function then just make it appropriately tight for the thread size (diameter) taking into account it's a hollow "bolt", which would reduce the strength a bit. IIRC, it has a sheet metal lock tab on it as well. In so many small or odd bolt cases on our bikes, just use good judgement and "feel" for the bolt size and function when tightening
 

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Good and snug is the torque spec to the neutral stop bolt. Then bend the lock tab into place
 
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