1990 V4 runs on two cylinders at low RPMs

[brodmann]

Basically, if you bought a non-OEM carb kit, I'd put your old floats and needle and seats in and only use the gaskets in the carbs. Did you get the lead plugs back in there and dimpled to make them fit tightly?

 

[goodmariner85]

Basically, if you bought a non-OEM carb kit, I'd put your old floats and needle and seats in and only use the gaskets in the carbs. Did you get the lead plugs back in there and dimpled to make them fit tightly?

Just saw your reply. Thanks. The kits were OEM. I tried both old and new needles when trouble shooting. Old needles looked to be in great shape (but there could be something I don't see).

I did not remove any lead plugs.

Before installing, I blew in the intake to make sure it was air tight. On at least one carb, it was not after sanding, so I took it apart and sanded again. On reassembly it was airtight.

 

[goodmariner85]

Engine ran quite well at all speeds for the last few weeks of the season, but there was a bit of a fuel leak, building fuel slowly in the engine housing.

Getting it ready now to put in the water.
* Engine will not start. It did start when on blocks last winter. A good amount of white smoke pouring out at the propeller.

* The bottom carb is leaking more fuel than before at the gasket. Of course I am pumping the bulb a lot, and it's not running, but still it should not be leaking at all. I'm not as overbudget as last summer. So I ordered the aluminum carburetor bowls, should get the first in a couple of days. One comment (only one) on a forum said well the metal bowls will warp too. I bet they're better than the plastic. Also two comments ten years apart said they got aluminum bowls and the intermediate jet receptacles were smooth, they forgot to cut threads. Fingers crossed.

* I did not get through my checklist last winter, which included spraying peppermint oil. So I have some chewed insulation on wire leading to coil pack. Wire only damaged a bit, most strands intact. I'll repair it (today I hope). But when I got it, the boat ran on three cylinders for a month. I even started it once on two when I was testing! I saw our new cat under the boat a few times last winter. If it weren't for the cat, I might have more damage.

* Looks like I have to pull the medium orifices out of the plastic bowls to look at the part number to replace them in the aluminum bowl. I have the OEM manual. It lists a bunch of jets but does not say which one is right for my engine.

* Compression was high and uniform last time I checked in the summer. But I'll probably check again.
* Regarding starting, I'll start with repairing the wire and checking that there is a spark jumping on all four plugs.

 

[goodmariner85]

One more follow up in case someone else has warped bowls:

I reinstalled the original plastic bowls while I was waiting for the new medium orifices for the aluminum bowls to arrive. I thought I have nothing to lose, so I screwed the four screws securing the plastics bowls very tight (with rubber gaskets). Now they no longer leak fuel. Have not leaked for a few weeks mucking with the motor and boat on dry land. To be clear, I sanded the warped surface flat last summer.

When I pulled the carbs off, I found that both upper and lower passed the blow-in-tube tests (see comments above) But the lower one had been leaking fuel. I suspect that a bit of air was getting through as well, but so small that it seemed air-tight when blowing in the tube.

I plan to just leave the plastic bowls on. If they leak, I'll swap out for the aluminum bowls.

The edges of the mating surface and the visible gasket are slightly wet looking. But any leaking is so small that I don't even see a drop form and no fuel is falling or running into the housing. There is a very slight fuel smell. Before, when leaking there was visible leaking fuel and a strong fuel smel..