can't figure out lean or rich on a 69 chrysler 55hp

n8dogg1616 · Aug 26, 2003

i am having trouble trying to tune the carb on my 55hp carb. it is a single carb on a magneto engine. the last time i took it out it ran great, but the top end was a little sputtery. (thinking it is lean) today i took it out and it would not idle or run smoothly, but top end was like a rocket.(indicating a little rich) the catch is that i have ajusted nothing on anything. i do need to ad that my fuel pump was all rusted out so i switched to an electric fuel pump and yes i have taken off the carb and cleaned it well.any help

The Marine Doctor · Aug 26, 2003

Re: can't figure out lean or rich on a 69 chrysler 55hp

Low speed jet setting is 1 1/2 turns couterclockwise. TMD

n8dogg1616 · Aug 26, 2003

Re: can't figure out lean or rich on a 69 chrysler 55hp

it is a tolliston carburator and there is only one jet and it is inside the bowl. there is only one ajustment valve and it is the gas/air needle and yes it is at 1.5 counter clockwise. really i think that the electric fuel pump that i have put on is to much pressure and is gettiing the carburator to much gas. what do you think.

The Marine Doctor · Aug 26, 2003

Re: can't figure out lean or rich on a 69 chrysler 55hp

Fuel pressure required is around 3-6 psi. Are you able to adjust the pressure of the pump? PS..the primer bulb will push around 30 psi...and does push fuel past the needle. But causes premature wear on the needle and seat. So if the pressure is too high..it will wear the needle and seat out. TMD

n8dogg1616 · Aug 26, 2003

Re: can't figure out lean or rich on a 69 chrysler 55hp

thanks for the advice, one more question though. is it ok to run the electric pump and if so is a car fuel worthy if the psi is 3-6. also running a electric pump is the primer bulb on the hose needed. thanks again for the help.

scotiany · Aug 26, 2003

Re: can't figure out lean or rich on a 69 chrysler 55hp

Question. Is your old fuel pump so bad that it can't be repaired with a NAPA fuel pump repair kit? They're less than $10.

The Marine Doctor · Aug 27, 2003

Re: can't figure out lean or rich on a 69 chrysler 55hp

As Scotiany is pointing out the original pump is a better option. This diaphram and gasket can be replaced for around $5.00. With an electric fuel pump you should no longer need the primerbulb. TMD

n8dogg1616 · Aug 27, 2003

Re: can't figure out lean or rich on a 69 chrysler 55hp

it is not the diaphram that is bad it is more the valves inside the pump are rusted and it is a little different configuration than i have ever seen and also there is not a napa auto parts store in the area. also guys i apperciate the info but what about the auto pump, if it is something that i can use and if so what modle or brand and size should i get.

seasprite2112 · Aug 27, 2003

Re: can't figure out lean or rich on a 69 chrysler 55hp

I just rebuilt my fuel pump a couple of weeks ago and the total costs with replacing the three valves was around $22.00. I know you can get the parts online but I was lucky enough to find them all locally. The valves are a pain and the only way I got them back in was to use an old AA maglight body to hammer them back into place.

The Marine Doctor · Aug 27, 2003

Re: can't figure out lean or rich on a 69 chrysler 55hp

I can probebly locate a used fuel pump here if you are interested. As for the Electric fuel pump...is there anyway to moderate the flow? TMD

eurolarva · Aug 27, 2003

Re: can't figure out lean or rich on a 69 chrysler 55hp

Sorry to beat a dead horse with the original fuel pump. If you are interested the Quicksilver part number for the valves are 21-F177330 (Quantity 3) The quicksilver gasket number is 27-FB4792 (quantity 3) The rebuild kit from napa or almost any marine web site is 18-7806. The rebuild kit comes with the valve gaskets but they dont fit around the spring side of the valve.

can't figure out lean or rich on a 69 chrysler 55hp

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