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Discussion Starter · #1 ·
I've got a 71 SL350 that I've had parked in my garage for a few years with intentions to set it up and ride.
I'm finally getting around to getting it running and preparing to plate for the road. I've read a few posts here and there about needing to replace the cam chain tensioner, which means I have to take off the head, cam etc. I've never done that. Thought I might just sell the bike, but....what the heck. Can anyone point me to a good post or just tell me what I should do to the engine once I have it torn down. I've seen some OEM tensioners on Ebay, but I assume the age thing is a problem with them also. So...where might I get those parts. Should I replace the cam chain, bore the cylinders, replace pistons, valve guides etc. Engine has about 2600 miles according to the Odometer.

I've made another post about where to send the cylinders etc. for rework.
 

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You can take the tensioner assy. off the rear of the cylinder(four bolts) and shine a flashlight in there to check out the condition of the roller. While it's off, loosen the adjustment bolt and slide out the adjuster plunger. Smooth out any marks on the top of the plunger(from a PO overtightening the bolt) so it will slide freely to adjust the chain.
 

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Discussion Starter · #3 ·
Does the cam chain have to be broken in order to install a cam chain adjuster?
 

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Does the cam chain have to be broken in order to install a cam chain adjuster?
No, the cam chain doesn't need to be broken to replace the tensioner.

As Mike mentioned, you can check the condition of the tensioner wheel by taking the plunger off the back of the engine. From there you can easily see the condition of the wheel. Here's a pic from mine showing a very bad one... pieces are missing and teeth have been worn into the wheel from the chain.

IMG_1148.jpg

Note that if the tensioner wheel is shot, there's a good chance the rubber chain guide on the front side of the cylinder will need to be replaced too. Mine had deep grooves worn into it that you can see below.

IMG_1183.jpg

IMO, just replace the tensioner (if it's bad) with OEM Honda parts. They're cheaper, quieter, and don't require modifying the head like some of the aftermarket options. The originals lasted almost 50 years on my high-mileage 350, good enough for me.

To replace them is pretty straightforward, although you will need to remove the head and cylinders to get access to everything. Loop a zip tie around the cam chain to prevent it from falling into the crankcase, and be very careful when removing the tensioner wheel... there are two small rubber bushings covering the ends of the pivot pin that can fall into the crankcase if you're not careful.
 
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