cold manifold

larry h in sc · Feb 8, 2011

I have a40s jd and manifold runs cold at carb.I have ck. timing adj carb still runs cold.can anyone help please.

Greenday · Feb 8, 2011

what do you mean? Do you mean it sweats or frosts a little bit where the carb connects to the manifold? If so this is very common for old 2 cyl's

larry h in sc · Feb 8, 2011

It gets very cold some frost if you run it long.I was wondering if maybe the gov.was acting up or the carb

buickanddeere · Feb 8, 2011

Remember physics class and the relationship between flow, pressure and temperature through a venturie?
Also that vaporizing liquid absorbs heat.

old · Feb 8, 2011

ALL engines do that and it is just the nature of the way carbs work. If it causes you a problem you can make a shield out of foil so the manifold will warm up. But either way it is just pure physics and every thing is doing just as physics say they have to

Sam#3 · Feb 8, 2011

As b&d says below you've made a small refrigerator. In priciple ALL Carburetors do it but isn't so noticeable on a downdraft.

jackinok · Feb 8, 2011

does yours have a hot and cold temp setting ? some would redirect heat around through manifold in winter to stop this.been a long,long while since I ran one,and dont recall exactly where,but look on head or intake for a small lever.I'll see if I can find info on this tonight.might ask over on the jd board surely someone there would know.

RayP(MI) · Feb 8, 2011

Our old JD B had trouble with that. Finally dealer installed a hotter manifold, that took care of the problem. I've had them frost up to the point where they wouldn't run.

Mathias NY · Feb 8, 2011

Out of curiosity, have you checked the air cleaner recently?

Some coolness is common in colder weather. A thick or dirty oil bath can cause the air to pull harder and lead to icing. Some operators manuals will even list a winter blend of the air cleaner oil to help cope with this.

Good luck.

Mike Aylward · Feb 8, 2011

Larry, I have LP manifolds on a few of my user tractors and they will do this as well. On an A tractor there is a pretty simple fix for this if the icing is causing trouble. Just get a piece of steel plate and lay it on top of the manifold with your method of holding it there. It will hold a lot of heat and eliminate most if not all of your problem. I use a piece of 3/8" flat steel that I happen to have around. Cheap and easy. Mike

cold manifold

larry h in sc

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Greenday

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larry h in sc

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buickanddeere

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old

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