1600 engine noise

Have you adjusted the valve clearance? Slack in the valve train will cause noise more noticeable when cold. An exhaust leak could cause this type of sound especially if close to where the exhaust exits the heads. In both cases expansion and contraction from changes in engine temp can cause changes in clearances.

Could be ignition system (plugs, cap, rotor), but I doubt it as that would likely happen at any engine temp.

Could be a couple things. I would start by double-checking the valve lash, a loose valve could be the culprit. The other thing it might be is a loose head. It would really depend on if it gets louder depending on throttle setting. If you goose the throttle and the sound becomes substantially louder, or if you get it rolling in say 2nd gear and then stand on it and it gets louder, then I would suspect a leak at the junction between the head and the cylinder. Reparing it properly will require engine removal. Personally, I would pull and inspect the heads, change the pushrod tube seals, pull the jugs and reseal those to the block, and then reassemble. It's a long afternoon type of job once you get the engine on the ground.

Good luck with it.

Chris

Before gutting anything. I would check for tight exhaust flanges. An exhaust leak at the head can sound like that. The most obvious cause is a lifter adjustment. A broke fuel pump spring could do it also. Get a wood dowel or rubber hose and use like a stethescope. You will get closer that way.

Jim SR Racing

I have adjusted the valves. the noise was there before the adjustment & after. A friend with more experience with these things suspected the fuel pump.

Thanks for all the advice!!!

Check the distributor shaft where the points ride it. If it's dry, it makes a whining "ticking" noise that could fit the description. Lube the shaft lobes lightly with something sticky.

Jan

I have a similar noise and it comes from the manifold heating tube. It has a small hole on it. It took me a while to find it and now I don?t know want to do. To replace it I have to pull out the engine. Any ideas on a easy fix?

Joao

But I have to remove a lot of staff and I was told that was easier to pull engine. Do you know how to do that with the engine in? I also have a oil leak and may be I will do at once. I never pull the engine off so I don?t know if I will try that. The jack that I have is a small one (2T) and I really don?t know if I go for it.

Joao

If you mean the heat riser to the carb, you sure don't have to pull the engine.

two-piece replacement?!?!? were to find them. I never saw this parts.

Joao

Following my own post because I won't be here to follow up. (Looking at an ice-bike in a few minutes. Hooo Rah for sub-zero sports!)

If it's the carb heating riser, just get a two-piece replacement. Cut the old one with a hacksaw, unbolt it, remove it and replace. You will have to take some things off to give you wiggle-room, but you do not have to drop the engine.

It's been a few years, and possibly they came along with a new manifold. Someone else will have to help. I'm mired in a waterhead VW engine project right now.