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

[n8dogg1616]

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]

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

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

 

[n8dogg1616]

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]

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

Fuel pressure required is around 3-6 psi.<br /><br />Are you able to adjust the pressure of the pump?<br /><br />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.<br /><br />So if the pressure is too high..it will wear the needle and seat out.<br /><br />TMD

 

[n8dogg1616]

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]

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]

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.<br /><br />With an electric fuel pump you should no longer need the primerbulb.<br /><br />TMD

 

[n8dogg1616]

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]

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]

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?<br /><br />TMD

 

[eurolarva]

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.