Jetting Question on 3 differnent carbs on same engine 150 v-6

[danielmorse]

I have just bought a 1979 v-6 150hp mercury sn#5342369. It has 3 different carbs on it, WH1-1,WH7-3, and WH4-2, top to bottom in that order. The casting number is 1374-5427 on all 3 carbs. The current jets in the carbs are .048 main, .056 idle, and .098 vent. The seloc manual has jet sizes ranging from .048 to .082 on the mains. The motor ran OK but not real smooth all the time. I ordered some new floats because the old floats were foam and broken . Does this jetting seem to be useable? Does anybody know the differences between the carbs? Thanks.

 

[danielmorse]

Re: Jetting Question on 3 differnent carbs on same engine 150 v-6

Bump

 

[Chris1956]

Re: Jetting Question on 3 differnent carbs on same engine 150 v-6

An OEM Service manual should give you the facts on your motor. A lot of times they call out the exact jets, plus jets for different altitudes.

 

[danielmorse]

Re: Jetting Question on 3 differnent carbs on same engine 150 v-6

I'm putting in new floats tomorrow. The old ones are foam and someone broke the metal tabs loose adjusting them. The place I bought it from said their mechanic just got out of school and he just rebuilt the carbs. Its on a 26 foot tri-toon, so top speed is not what I am going for, just reliable starting and running. The carbs are from 3 different motors and have marks on them from being rebuilt several times. I think it has been running a long time like this. I will take it out and see how it runs. The only manual I found was the Seloc manual, which I bought. It had a chart listed by carb model, not on year model of motor. But with random carbs the charts are out the window.

 

[danielmorse]

Re: Jetting Question on 3 differnent carbs on same engine 150 v-6

The floats don't fit. I have early model WH carbs with round shaped floats. The ones I got from Midwest are different shaped.
I went by the Mercury dealer and they had an set of WH 29 carbs on reed plate from an blown up motor and I bought them. They look unmolested, and have the enricher system on them. I will start a new thread for advice on how to install them. The jets in the carbs are the same as in the manual.

 

[Faztbullet]

Re: Jetting Question on 3 differnent carbs on same engine 150 v-6

Floats for WH carbs are NLA from Mercury...

WH1-1,WH7-3, and WH4-2,

Those carbs should all have a .074 main, the wh-1 and wh-4 should have .048 idles and the wh-7 should be .044, the vent jets on the wh-1 uses 6 jets, cyls 1&2 use .090 and remainder are .082. The wh-4 uses 6 jets and and all are .094. The wh-7 carb use 3 jets as cyls 1&2 are .090 and cyl#4 a .082.

 

[danielmorse]

Re: Jetting Question on 3 differnent carbs on same engine 150 v-6

Thanks for the reply. 3 different carbs on the same motor seemed unbalanced to me, the internal passages are probably different and the floats are patched with JB Weld, so the WH-29s were a lucky find for me.
Thanks again