Engine runs good but cranks for too long to start?

Anonymous-0 · May 1, 2010

The Continental F162 in my, new to me, welder runs very good but at first start up seems to have to crank for too long. It runs great after it starts and starts right up after it's been shut off for about and hour or 2 but overnight has to crank longer than normal again. It uses a magneto but I'm wondering if it's more a fuel problem from loosing prime, etc? I've heard you should have the fuel line run staight down to the carb without any slack. The sediment bowl was replaced and it has an inline fuel filter. One clamp is missing on the fuel line but it doesn't appear to be leaking. Could just the missing clamp be enough for a slight air leak after sitting overnight? Most other welders like this start in about 3 cranks. Any ideas would be appreciated. Thanks. Dave

Jack345 · May 1, 2010

To confirm fuel problem give it manual prime with starting fluid when cold. If its a fuel problem check to see if it has gas in carb it could be leaking or boiling out. Or vacuum leak between intake and block.

Don-Wi · May 1, 2010

My first thought is to get rid of the inline filter unless it was designed to use one. Something tells me otherwise though and that it should just have the sediment bowl.

Probably doesn't have much effect on your starting though. If the fuel tank is above the carb, there shouldn't be any air getting in at the missing clamp, but I guess it could be possible. Does it crank a little slower than it should?

Donovan from Wisconsin

Anonymous-0 · May 2, 2010

It turns over good. I even read that with mags it's sometimes better if they turn over slower. It has to crank for 15 to 20 seconds but after it's been run it cranks for about 5 seconds like all the other similar machines I've used. It did seem like there was a tiny bit of fuel on the carb drain plug. I tightened it just a touch. There is a rubber washer of some sort on the bolt and the carb is brand new. Maybe there is just a tny, tiny fuel leak that is making the carb lose it's prime? I'll try it tomorrow and see how it starts. The fuel shut off line goes lower than the original sediment bowl would. The carb is still lower but the fuel line is almost horizontal instead of down all the way to carb. The inline filter is clear and doesn't completely fill with fuel. A mechanic is the one who suggested it's losing its prime. That kind of makes sense that it has to crank longer to get enough fuel into the cylinders. I'm thinking it's more a fuel problem than a mag problem cause it only does it when sitting for a long time. Dave

Puddles · May 2, 2010

I know exactly how your machine feels! I don't like to start either, be it in the morning, after a break even more so after lunch.

I have a 1974 “Green light” machine that is hard starting, don't remember it being so hard before having Murphy switch installed. When it starts it acts like it is only running on 3 cylinders for a few seconds, but then takes right off. Machine has a new Zenith carb, new (copper core) plug wires, and extremely good spark, with very good compression! Just one of those things I guess!

My 1966 Redface starts with just a bump of the button, with no choke.
My 1954 6-volt system it starts really well but needs to be choked.
My 1948 12-volt system starts very well also, but needs to be choked.

There is something to be said about slower revolution starters with a magneto. Friend of mine use to have a shorthood with only a hand crank, fired right off no matter the weather! Seems to be no rhyme nor reason to these old girls, they all have their quirks.

What brand of spark plugs are you using?

circus · May 2, 2010

Carb is dry so it takes a few seconds to fill. An electric fuel pump will fix it. All my seldom used carbureted engines use to crank a long time to start after sitting. Now I just turn the key to on then wait 5 seconds before cranking. Electric fuel pumps also make bleeding air from a diesel a breeze.

Anonymous-0 · May 2, 2010

They put new AC plugs in it. The spark plug wires aren't the solid core but the engine runs fine once it's going. The wires are yellow and say radio suppression core on them. It cranks, then fires a couple times and after cranking a little longer starts up. I thought I read somewhere that the fuel line should run as straight down as possible. On a site about aircraft mags it said that on those if they crank too fast the impulse timing of the mag isn't timed right for it to fire at the right time. I'll see what it's like today. Dave

jbp · May 2, 2010

Magnetos don't like graphite plug wires. Replace the wires with copper ones and your problem should be solved. Joe

C.R. · May 2, 2010

don has it I think loose the inline filter the sediment bowl does the job

Mike M · May 2, 2010

I agree with the fellow that says to ditch the radio suspression spark plug wires ! These don't work well on magnetos.

If that doesn't solve the problem then next check for a bad fuel pump if equipped with one.

Also how are you shutting it off ? don't choke an engine to stop it ! try shutting off the fuel and letting it run out then turn it on before starting and if gravity feed is working right it will fill up the carb. in no time so it has fuel to start.

Puddles · May 2, 2010

Ditch those AC plugs, I found Denso L14-U to be the very best, and Autolite 386 to be a very distance 2nd. I cannot get Denso plugs locally Napa won't even order them in for me. I buy online from “Sparkplugs.com”.
Get rid of the graphite wires as jbp mentioned, he is 100% correct! Magnetos will eat those wires like candy! You do kill the engine with a ground wire and switch to the stud on the side of the mag, don't you?

msb · May 2, 2010

Is the choke closing all the way ?

DickL · May 2, 2010

To start easy you need a pool of gas between the power jet and the feeder tube. Sometimes this area gets crud in it that diminishes the size of this area. It also get overlooked when cleaning a carburetor as the feeder tube and jet has to be removed to get something like a small drill down in to scratch it loose. If you don't have that pool of gas the gas has to be drawn with vacuum thru the power jet and up thru the feeder tube or discharge jet before it can get into the cylinders. (what ever your terminology for is it.)

Anonymous-0 · May 3, 2010

Yes,the ignition switch goes to the mag terminal. The engine runs good once running and starts easily as long as it doesn't sit for long periods like overnight. Would the wrong plug wires cause that? I'll see if I can find the Denso plugs. What about NGK plugs? I've always had gook luck with them. I still kind of think it's a fuel problem but I'm no expert. The drain bolt on the carb had a slight touch of gas on it this morning. Maybe it's too tight? It has a rubber washer on it. Maybe I should loosen it and just put it snug and not real tight? It doesn't drip. Maybe the Zenith carbs just don't hold prime for longer periods? Kind of bizarre for sure. Dave

Anonymous-0 · May 3, 2010

It's a brand new carb. One of the fuel lines to it is pretty old though. When the sediment bowl was replaced with a different fuel shut off, the fuel line to the carb isn't on a very downward angle to the carb. I read it should be as short as possible and on a downward angle all the way to the carb. I'll see about putting a sediment bowl back on and getting rid of the inline filter. Maybe it gets a slight air lock after sitting overnight? I was even thinking about putting a primer bulb on the fuel line, like on a boat, to make the initial start easier. I'll do some experimenting with different things. Dave

Anonymous-0 · May 3, 2010

Yes. Dave

Puddles · May 3, 2010

The wrong plug wires will make it run bad, and hard to start, but it will take some time for the quality of the wires to deteriorate. I've had good luck with NGK plugs too, especially with high revving 2-stroke engines! Don't know why I didn't check to see if NGK makes a plug to fit these machines.

I think you have a fuel problem too, I've been reading everyones suggestions to see if I can find the solution to my hard starting '74'. I just wrote it off to the Murphy switch. It takes quite a few revolutions for the green light to come on as it is. I like the idea of an electric fuel pump, and your idea of the primer bulb! I would change out your fuel line for sure, and use all new hose clamps. I would leave the inline fuel filter tho. Kaye Sellon highly recommends them. You know this updraft fuel system is not the best invention. But it is strange how some machines start so easy and others hard.

Keith Molden · May 3, 2010

Don't know if this helps or not, but I put an in line filter on a 350 International utility & it was terribly hard to start. I took it back out & it started as it should. You might want to put the sediment bowl back on & remove the inline filter & try it. Can't hurt to try. Just my thoughts, Keith

Anonymous-0 · May 3, 2010

For 2 stroke MX bikes NGK is the way to go. I don't think the plugs are the problem but new ones are pretty cheap. I think the NGK cross over is an A6 according to a chart I looked at online. I'm going to go to Continental engines and see what they say. I think I'll put the solid core plug wires on and new fuel hoses and see if it starts easier. I think it may have started easier if I cranked it for about 5 or 6 seconds, then let it sit for a few more seconds before cranking it again. You said your 74 has a new zenith carb too, so I thought that could be a common denominator??? Hmmm. Dave

Anonymous-0 · May 3, 2010

The inline filter doesn't fill completely and is almost horizontal rather than vertical. Maybe it allows a tiny bit of air after sitting overnight? Dave

Puddles · May 3, 2010

Yes all my machines have Zenith carbs.

trucker 40 · May 3, 2010

Try the plug wires and see if that fixes it.Then if the inline filter is what kind I think it is,look and see if it is on there the right way.It ought to say inlet on one side and outlet on the other.Maybe take it out and get a sediment bowl and see if that fixes it.I bet its those plug wires though.

jpapier · May 3, 2010

Sediment bulb for gravity feed, inline filter for fuel pump. Don"t mix them up.

Engine runs good but cranks for too long to start?

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