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Post by BritPete on Jan 24, 2021 14:18:27 GMT
While SME's engine is out of the Frame I have adjusted the Cam Chain Tensioner And the Tappets But worried as the inlet was only at 6 thou should be 10 Exhaust at 8 thou should be 14 Unless I have not spotted they are different on the NC engine Going to get Neil to double check them in case I am doing something stupid The Primary Chain adjuster This is a photo  The book says loosen the left nut and it will adjust its self It seems a bit stiff, assume put a little bit of pressure Anti Clockwise and leave it like that Am I correct The engine was running fine before I started the refurb and I have done nothing to it apart from paint the outside |
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Post by buster on Jan 24, 2021 14:44:17 GMT
not sure wether your working in english or metric on the valve clearances, 0.1mm inlet and 0.14mm for exhaust, 0.004" inlet (4 thou) 0.005" exhaust (5 thou)
easy check to see if haynes have it right divide 0.1 by 25.4 = 0.003937 (so 4 thou)
I'v only done the balance chain adjustment with the engine in bits (when your building it its upside down) the spring that sets the mechanism is very soft (this is likely how the chain gets over tightened and then chews away at its rubber guides). I'd try backing the other nut off a little (2 turns maybe?) and pull the adjuster towards you a little (its on splines so you wont lose its position) and with everything as free as it can be feel very gently for the spring tension. pull it against the spring and release it and it should 'flick' into position (may need a few goes to free the mechanism) when it reaches its own position after the flick its then set and you can firmly nip the nuts back up
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Post by BritPete on Jan 24, 2021 14:50:39 GMT
not sure wether your working in english or metric on the valve clearances, 0.1mm inlet and 0.14mm for exhaust, 0.004" inlet (4 thou) 0.005" exhaust (5 thou) easy check to see if haynes have it right divide 0.1 by 25.4 = 0.003937 (so 4 thou) I'v only done the balance chain adjustment with the engine in bits (when your building it its upside down) the spring that sets the mechanism is very soft (this is likely how the chain gets over tightened and then chews away at its rubber guides). I'd try backing the other nut off a little (2 turns maybe?) and pull the adjuster towards you a little (its on splines so you wont lose its position) and with everything as free as it can be feel very gently for the spring tension. pull it against the spring and release it and it should 'flick' into position (may need a few goes to free the mechanism) when it reaches its own position after the flick its then set and you can firmly nip the nuts back up Thanks Buster Read 0.10 mm as 10 Thou not 4 Thou They were probably correct before I changed them Senior moment Need to readjust them - B0110CK5 |
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Post by buster on Jan 24, 2021 14:57:05 GMT
just had a quick look in haynes (page 44, paragraph 8) so if I'v worked this out right you should lift the balance chain tensioner and see if it flicks back into position, if it comes back on its own spring (the very soft one) then thats job done, nip it up its set.
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Post by johnjones on Jan 24, 2021 15:35:22 GMT
400 engine then.
Thats's the adjustable adjusting quadrant for the balance chain adjustment, which is self adjusting, as the shaft with the 14mm af nut on will rotate anticlockwise to auto tension the balance chain.
They do suffer from sticktion and require the flicking process described, but would avoid pulling and pushing the shaft in and out, rather turn or flick the shaft back and forth, so it returns in anticlockwise direction due to the spring.
An exploded view of this area of the engine will help, and knowing of the eccentric.
In your picture the dot is in a good place, hope it stays where it is when you adjust the quadrant relative to the shaft.
If you are repositioning the quadrant, with the 12mm slot nut locked, undo the 14mm nut, then the 12mm nut, and remove the quadrant.
Refit so you have max slot and lock the 12mm nut, then the 14mm nut, then test adjustment.
If you look thru the gap between the main bearing ladder casting and the front of the crankcase, you will see the chain, and probe for any slack etc..
You know of the dot relevance, 3 o clock fully unadjusted, thru noon to 9 o clock full adjustment.
If the dot ends up below the horizontal, bad, engine out and sump off.
You do not have to remove the cylinder head to work on the bottom end bearings or balance chain ( but fully slacken the cam chain will help ) thus avoiding the sometimes very troublesome 4 centre head bolt problems.
Now you know what to look for, you will be able to see the dot and chain and probe chain thru the round slotted plug 😃.
Do not do this with the engine running !
The gasket cement between the sump and upper c/case oooosing out, is the same colour on the rear c/case joint, by where the kickstart would live ?
Looks like honda bond, so engine has never been split ?
Now is the ideal time to flush out the sump of all the debris that is in there. Also flush out the kickstart oil trough.
If you have the clutch peg spanner, remove the clutch and clean the inner finger faces as they will be covered in crap also.
If you don't have the peg spanner, solvent clean the clutch as best as possible paying particular interest to the inner faces of the clutch basket fingers, as they tend to act like a centrifugal oil filter.
Do not over tension the balance chain as that will promote rapid wear of components in this febble drive arrangement.
When you removed the clutch cover, did crap from the oil pressure switch area fall all over the primary drive gear on the crank ?
It usually does!
Note, use parts exploded view to find out if your engine has the cush drive balance weighs.
The rubbers compress and go rock hard.
The drive sprockets have been known to disintegrate.
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Post by andy1kenobe on Jan 24, 2021 15:44:11 GMT
The Haynes states 4 thou inlet, 5 thou exhaust and does not mention any difference in the NC section at the back.
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