maniofold gaskets - to seal or not

Should I be putting anything on inlet/outlet gaskets to better seal them. I'm still getting very odd behaviour from my landy with it seemingly running well then dying/going lean at idle. I've checked all hoses etc and plugged servo, PCV hose, advance but still sommat up.

I've got the exhaust off anyway so I'm gonna try another new manifold gasket - I've got the combined ones and some inlet only tin ones, should I be prepping the gaskets? I've only never had combined ones before and usually put some silcone on the inlet ones.

fit dry ,i prefer later one piece gasket ,but remember you need to slacken the 4 clamp bolts that hold the two manifolds together

Thanks James, I'm assuming you mean slacken off before popping the two manifolds in place?

I'm, starting to think there might be something going on with cam chain. Wonder if the tensioner isn't doing the business properly. Seems to run fine when its pulling but all goes wrong when its idling or on the overrun. I can't figure anything else as I've tried resetting points and timing on a new distributor and even tried a powerspark electronic points but is still misbehaving.

Will report back after another look tomorrow...it's a shame cos when its driving it seems to be going well...

have you tried a strobe light to see what timings doing

Good idea. It's spot on when I set it up. Not had it with me to check when its playing up. I'll keep it in the car ready to check it.

you should be able to see if it advances/retards smoothly or flutters

Ah, I see to check chain tension....good point. Will double check but it seemed pretty good when I checked it yesterday.

yes and also dizzy wieghts and operation

Dissy seems to be working ok, I checked that everything was free when I put it together yesterday, weights, vacuum etc and checked that it advanced to about 40degrees when I put revs on. Seemed fairly smooth but the odd jiggle at idle.

What carb has it got?

It's a Weber 34ICH. It got a bigger idle jet in as I was struggling to get the right mixture.

Well, did the exhaust and it was still playing up so checked timing and it seemed ok. My mate reckoned there would be more noise from the chain if it was lashing around so I stripped down the carb instead and fitted a new set of gaskets: carb top, bottom, and adaptor. Cleaned up all the surfaces and just used a film of grease on the gaskets to make them soft. I had to make my own one for the carb bottom.

Fired it up and it still seemed difficult to get it to do a reliable mixture with the lambda sensor. It hunts around slowly but seems to run better now.

I rechecked the timing, got my mate to hold the throttle while I checked the advance and its dead smooth from about 6BTDC at idle up to about 40 at 3500 RPM with the vacuum advance off. Stays where its put rather than hunting around so I think I can stop fretting about cam chains and tensioners.

I only got a chance for a quick 5 mile run but brayed it on the way out and took it more gently back up the windy hill. Pulled well and behaved impecably. Mixture was roughly where I'd set it when I got back, just a tad leaner. Not enough of a change to worry about as it will have been hot when it got back and just warm when I set it. The mixture screw is about 2 and a half turns out.

So it looks like it was those gaskets. I'll take a few sheets of gasket paper with me when I go to France in a couple of weeks! Hopefully if the weather stays fine I'll get a chance to go out in it over the weekend to give it a check

D

PS: Meant to say thanks to everyone who's chipped in with suggestions. I'm hoping this is now all sorted.

I think I've now convinced myself that I've done the cam chain properly but keep getting the urge to take out the rad and have a look behind the front cover...