Rattling

[leon#51]

Hi i wonder if use can offer me sum advice, ive fitted sp cams to my race when rebuilding the engine and now its very rattley at the top end, it never done this before i fitted them. Its a normal l model engine with new sp cams, i now these engines are noisey but this is redicilous. Do the sp models have different valve springs? Maybe softer to quiet it down?

[RedexRobB]

did you measure the valve clearances after fitting the new cam? Fitting the new cam will cause the top end to have completely different clearances compared to the original and are probably now all over the place.

Either that or you havent set the tensioner propely perhaps?

[leon#51]

Yep valve clearances, cam timing and chain tension is all good. I lapped the cams in and everything but it still rattles.

[RedexRobB]

have you re checked it all since?

[Fatspanner #44]

Is the camchain tensioner ok? I have seen two faulty ones in the last 6 months on a couple of engines where you can push the plunger down. May just be the valve clearances needing rechecked though.

[Marcie]

Does the noise dissapear or quieten when you engage the clutch? If so it will be the clutch basket, mine sounds bad on tick over. But no harm to be done.

Marcie

[leon#51]

Na its not the clutch. Its defo top end, its really bad through out the rev range and get to the point you think its gonna brake at 6k rpm but it gets quieter after that.

[coley]

Hi Leon little cheat for tensioning the cam chain is to slacken the 2 8mm headed bolts off on the tensioner and pry the tensioer body down till you hear (feel) it click once then tighten the 8mm bolts back up, and fire up and see if that is better. If not repeat. Alternatively go to Cradley Kawasaki and spend £52.00 on a new tensioner. Hope this helps and makes sense. Cheers, Ben

[cargo]

Thats very naughty Ben..................... very very naughty

Really what you have suggested compensates for a weak spring in the tensioner. I reckon you'd need to be careful not to over tension the chain.

I've got an old broken tensioner and have thought of trying to turn it into a manually adjustable tensioner. I think Roger has done this with some success.

[coley]

Naughty but works if you are careful (one click and then check). Surely by doing it this way it acts like a manually adjusted one?

[jake]

Ive seen a few guys with the manual adjustment tensioners... just whack bolt through the tensioner body. They work well enough im told, a bit leaky id imagine. Proper paddock engineering

[leon#51]

I think il re tighten my cam caps then recheck the valve clearances, what valve clearances do use guys set them up to? Im going on inlet 0.20-0.25 exh 0.25-0.28. If this doesnt solve il try the tensioner, but the rattlings there all the time throughout the rev range.

[mark400]

ZXR's regularly split/crack their cam tensioner blade, although it stays in one piece.

[fatboy]

12-17 inlet 16-21 ex

[cargo]

OK boys great topic and worth getting it right.................

Ben I think your method is fine so long as great care is taken

Modifying a tensioner is better than Bens method it give greater accuracy and if the tensioner ratchet is broken it doesn't matter.
It takes very little to damage the tensioner ratchet just a very fine piece of metal broken off the teeth or pawl and it fecked.

Now to valve clearances....................

Leon#51 I have know idea where you got those figures from but they are wrong wrong wrong

Fatboy your figures do not make much sense either because you have omitted the decimal point....................

The correct clearances are for both H and L models

Inlet............ .12 to .17 mm

Exhaust......... .16 to .21 mm

Now you go try buy some metric feeler guages and you will find that most of them on sale in most tools stores Halfords etc will not have small enough increments in the sizes to be able to measure your clearances............you can get them but I suspect price would be an issue.

However most imperial feeler guages do have sufficently small increments to do the job and as I'm a tight butt I've used my imperial guages for years now with no problems.

So valve clearances in inches are

Inlet....... .0047209448 to .006692913385 inches

Exhaust...... .006299212598 to .008267716535 inches

Look complicated I know but in truth is easier I work to

Inlet...................... 5 to 7 thou

Exhaust...................... 6 to 8 thou

Using those figure you might just get a slightly tight exhaust so better to be a lose 6 that a tight 6...................... better still 6.5 thou

This work fine for me.

Leon#51 if you have set your clearance to your figures they are too big........................rattle rattle rattle