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wrong carburetor?

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JimF
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wrong carburetor?

Post by JimF » Fri Aug 02, 2019 10:38 am

I took over a 1956 Capri project from a man who lost interest. The engine ( KL-QXLDML stamped on the block) was rebuilt and according to the receipts so was the carburetor. I am trying to start it but it will only fire if I give it a little spray ether and then it quits. I t seems clear that it is not getting fuel. The fuel pump is working and there is gas in the carb. I loosened the plug at the bottom of the carb body and gas came out.

Upon looking at the carb, it has a tag # 11849 which, according to Classic Boat Connection catalog, is for a KLC. Is this a problem? It seems like a KLC has more horsepowers therefore should be providing plenty of fuel.

Amy ideas on how best to get this beast fired up?
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1930 Chris-Craft Model 100 20' "MOXIE"
1935 Chris-Craft Deluxe Utility 18' "ALICE K II"
1940 Chris-Craft Red and White 25' "Old Paint"
1946 Chris-Craft Sportsman 25' "CinCity"

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Bilge Rat
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Re: wrong carburetor?

Post by Bilge Rat » Fri Aug 02, 2019 2:31 pm

Some things to try:

Is the choke fully closing? Verify by looking at the choke plate (NOT WHILE CRANKING!).

Is the carb flooding? Its very easy to flood an updraft carb. There should be a drain plug at the bottom of the carb where the air horn bends up if you see gas puddling inside the bend.

If its been sitting for a while after the rebuild, it might be possible a valve or 2 are stuck open, causing zero compression on some cylinders. The ether may temporarily overcome this for a quick pop and no running. Verify by performing a compression check.

Verify the firing order and static timing.

Are the battery cables of sufficient size to prevent voltage drop at the starter and distributor? Too small and the starter cranks too slowly and there's not enough voltage to reliably fire. If this is running on 6 volts, that means 1/0 copper cables. Verify you have full voltage at the starter and distributor while cranking.

90% of fuel problems are not the carb or fuel. Could be an ignition issue. I assume that you've never seen this engine running? Even if this is the wrong carb, it should still start and run, just possibly not produce all the rated horsepower.

This much I do know, if this was a complete rebuild including any cam/lifter/valve work you need to get this engine started and running at around 2000 RPM ASAP, don't let it idle for long. All this cranking is wiping the cam lube off of the lobes and until its running near 2000 RPM, there's no lubrication on the lobes as they are lubed by splash oil. It needs to run at that RPM for at least 20 minutes.

When you do get it running (notice I didn't say if), don't forget to re-torque the head nuts when you shut down and again after subsequent runs and once again when you have it out on the water. You may have to do this at least 3 times otherwise the head gasket will leak.
1966 Lyman Cruisette 25 foot "Serenity Now!"
1953 Chris Craft Sportsman 22 foot "Summerwind"

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JimF
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Re: wrong carburetor?

Post by JimF » Fri Aug 02, 2019 4:21 pm

Thanks for the quick reply.

I looked at the rebuild receipt and the work was done in July 2015 so the engine has just been sitting since then. It was never installed in the boat and is on a stand in my shop.The previous owner never saw it run but assured me the shop had run it.

It is 12 volts and cranks over quickly. Yesterday I did check the firing order and the timing. Pulled #1 plug (flywheel end) and using my thumb felt when it compressed and noted where the rotor pointed. It was right at the #1 wire and there was a mark that the rebuilder had made so I think I am good there.

I had been trying to start it with the choke open so the ether could get in so maybe I should try with the choke closed and no ether.There was no puddle of gas in the horn.

I have an ignition wire from the battery (+) to the coil (+). I disconnect when not trying to start.There is Petronic ignition installed.

Tomorrow I will check compression. It is 100 degrees out now so early morning is the time to work.

Thanks so much for your help.
1930 Chris-Craft Model 100 20' "MOXIE"
1935 Chris-Craft Deluxe Utility 18' "ALICE K II"
1940 Chris-Craft Red and White 25' "Old Paint"
1946 Chris-Craft Sportsman 25' "CinCity"

jim g
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Re: wrong carburetor?

Post by jim g » Sat Aug 03, 2019 8:52 am

Since it will start on ether and you confirmed there is fuel in the float bowl. The carb is more then likely stopped up with old fuel and probably rust.

Give it a go with trying to start it with the choke closed as the choke creates more suction in the carb so it pulls more fuel to go to the cylinders.

But more then likely it will need a card rebuild after sitting 4 years.

As to the carb being the correct one. I suspect it is. Most of the Capris came with the KLC. Also the intake manifold is different as the KL carb and the KLC carb have different throat sizes which make the stud spacing on the 2 carbs different lengths. So basically the carbs are not interchangeable without changing the intake manifold. Also I have never seen any of the Chris Craft engine designation letters stamped were Hercules stamped there numbering.

Can you post a picture of the stamping?

Also the KL used the K stepped flywheel and the KLC used the flat lighter weight flywheel. The only real way to know for certain is to see what camshaft it has in it.

Also there is no need to worry about running the engine at 2000 rpm for 20 minutes. This is for new camshafts. Which is called wiping in. It breaks in the cam lobe to the lifter. There have not been new camshafts and lifter available for a very long time.

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JimF
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Re: wrong carburetor?

Post by JimF » Sat Aug 03, 2019 9:36 am

I checked compression this morning. All are 115-125.

There was gas in the horn so I drained it. Looks rusty. Tried starting with choke full on with no ether and engine fired as long as the starter was turning it but quit immediately when I released the starter button. The horn again had a lot of gas in it.

I am really thinking it is the carburetor and I should send for a kit. I hadn't thought about that it had been sitting with fuel in it for 4 years.

I am posting some pictures of the engine for identification purpose. I do hope it ia a KLC. Would love the extra horsepower!
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1930 Chris-Craft Model 100 20' "MOXIE"
1935 Chris-Craft Deluxe Utility 18' "ALICE K II"
1940 Chris-Craft Red and White 25' "Old Paint"
1946 Chris-Craft Sportsman 25' "CinCity"

jim g
Posts: 1002
Joined: Wed Dec 14, 2011 10:55 pm
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Re: wrong carburetor?

Post by jim g » Sat Aug 03, 2019 11:10 am

Hi Jim,

The stampings on the block are the Hercules stamping which says its a long stroke marine engine.

Flywheel is correct and the intake has to be correct since it has the KLC carb on it.

I feel that it is a KLC. No real way to be positive until the boat is driven.

Rebuild the carb and that should fix the problem.

You can't trust what the plate on the manifold says. Over the years used manifolds were put on engines and the plates were never changed.

A KL 105hp would be under powered of a 19' Capri. I had a customer who had a 18' Rivera that came with a K from the factory and it would barely get on plane with one person in it. Kinda like a 16' Rivera with a B 60hp engine in it.

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Bilge Rat
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Re: wrong carburetor?

Post by Bilge Rat » Sun Aug 04, 2019 2:43 pm

Yeah that old gas looks a bit suspect. I agree about the carb needing to be opened up. The Zenith carbs are not that complicated but there are a lot of tiny bored passages that will trap rust and cause problems. Some have to be probed with a small gauge wire to free them up.

BTW, I used to have a KLC in a 17' Sportsman and it was a nice powerful engine for that boat.
1966 Lyman Cruisette 25 foot "Serenity Now!"
1953 Chris Craft Sportsman 22 foot "Summerwind"

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