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Discussion Starter · #1 · (Edited)
I've read and re-read the manuals. Even youtubed it but for the life of me, I can't seem to get the alternator rotor to fix on TDC for the left cylinder on the compression stroke for setting the tappets. The rotor simply springs beyond the setting by about 60 degrees. Witnessing the left side intake valve depress on the downswing, close on the upswing, the rotor springs past the "LT" TDC mark no matter how slowly I rotate. What am I missing? Sparkplugs are removed, compression is decent. A couple of thoughts:

1. Perhaps the PO removed the rotor and didn't position it properly?
2. I've done something bad - I do know that I rotated the rotor clock-wise for a few rotations. Can this harm something? I've found nothing to suggest it does.
3. This is unrelated but a lot of oil has come out of the alternator. A pic might help but I'd say it's at least 4 ounces.

Someone is going to point out something obvious. At least I hope so.
 

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Put the bike in gear then use something to hold the rear wheel which will hold the crankshaft in the proper position while you adjust the valves. Small children are good for this if you're fast enough to complete the task within their attention span.
 

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I made a stopper from a piece of aluminum and bolted it onto the crank case to hold it against the rotor. Once tightened down a little it allowed me to turn the crank slowly and having enough resistance to hold the rotor in place. Here's a crappy drawing that will hopefully explain things.


Untitled.jpg
 

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Use a box wrench....NOT a socket/ratchet.....
Also, taking out the spark-plugs will help a little....
 

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Whats happening is a valve spring is forcing the engine to spin by pushing a cam follower against a closing side of one of the ramps. You probably don't need the crank set just perfect to adjust valve clearances as long as it's not on a ramp part of the cam. Sometimes you'll have 2 thous clearance at one point 4 at another and 6 at another. It probably depends on your cam bearing journal wear and whatever direction the chain is pulling on the cam at the moment. And I just realized this is a single cam 350 were taking about?
 

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Discussion Starter · #6 · (Edited)
Gang - thank you so much for your suggestions. As you've probably already guessed, I'm completely new to this bike and learning about the nuances that aren't described in any manuals is part of the fun and learning.
Also, I tried to search for the techniques above - have they been discussed in other threads/posts? I once posted on the r1150r site somewhat of a guide of things to do/know that are not explained anywhere else (e.g replace the plastic fuel disconnects before they fail you somewhere inconvenient).
 

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Discussion Starter · #7 · (Edited)
It's a CJ360T single cam. As I use a box wrench to rotate the rotor, I'm careful to note that the left intake valve goes down as the "LT" is opposite of the stator's index marker. As it swings up during the Counterclockwise rotation, it compresses and then lunges past the "LT" rotor marker. I posted because I thought that it was quite odd that a rotor wouldn't stay positioned at the LT for tappet adjustment but would be on a downswing tension. Intuitively, it didn't make sense to have tension during an adjustment.
 

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I'll set the clearances on my 450 about 30 degrees before the opening ramp because I feel that's where you'll have problems if it's wrong and the spin the engine and check every 30 degrees or so to make sure it's not too tight. Too loose is probably fine as long as it's right before the opening ramp. Wear, tolerances, and spring force acting on the cam can make it a pain but after doing it a few times you'll figure out how to adjust for a smooth running engine. Too much clatter is bad. 450s quiet down some after they're warmed up good I'm sure 360 are the same good luck!
 

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OP, you understand now that the opposite side is the side with tension, and that it is normal for it to jump past the mark, correct? I carefully align the mark and use a shoe lace to hold the wrench in position.
 

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Discussion Starter · #13 ·
Ha! Sometimes I feel like I'm dense as a brick. But this image actually is interesting as the spring lash for me is counter-clockwise whereas this image would prevent lash going clockwise. Am I missing something? Also, I checked my BMW Clymer manual and it instructed something similar to J-T suggested - "Shift the transmission into 5th gear; rotate rear wheel in normal forward motion until the camshaft has completely opened the intake valves and then allowed them to close". No small children needed!
 

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What about pulling the plugs?
 

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Discussion Starter · #15 ·
Yup - did that. I think it's the concensus that there's spring tension at LT during the compression stroke. I'm going to see if there's a Honda Twin meet up in the DC area - might meet fellow wrenchers.
 

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On a 350 you can turn the engine over so the nub on the end of the cam points to the 5 o'clock position (some 140 degrees) to close all the valves, and set all the valve lashes at once. There is no spring tension at that setting.
 

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That's a really smart idea, I never had any problems buy may make one of them as it should make life even easier :cool:
 

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I made a stopper from a piece of aluminum and bolted it onto the crank case to hold it against the rotor. Once tightened down a little it allowed me to turn the crank slowly and having enough resistance to hold the rotor in place. Here's a crappy drawing that will hopefully explain things.


View attachment 71608
That's a really smart idea, I never had any problems buy may make one of them as it should make life even easier :cool:
 
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