2 barrel Rochester rebuild question

[96lt4c4]

I am wondering which needle to use in the rebuild kit, the solid or spring needle. The instructions to the kit I bought say the spring needle is recommended over the solid. I put in the spring needle and adjusted the float height to what the instructions said 14 mm float height and 27 mm float drop. It seems that with this needle the float shuts the fuel off to early and would not allow fuel to get into the accelerator pump. Does the fuel pressure just push the the needle down against the spring to get more fuel in the bowl?

I put the solid needle in and readjusted the float to spec, 10 mm height and 27 mm drop. This seems like it would allow more fuel into the bowl.

 

[newboater2day]

Re: 2 barrel Rochester rebuild question

use the one that look like the one you took out

 

[96lt4c4]

Re: 2 barrel Rochester rebuild question

Anybody?....

Spring or solid needle???

 

[Maclin]

Re: 2 barrel Rochester rebuild question

What kind of set was in there?

If you are sure the carb kit is for that carb then make sure you are not reading from an "offroading" section or something, or that the spring loaded needle is only recommended when using a higher pressure fuel pump. If you are sure the kit says use that one in all cases then follow it. The spring loading is meant to keep the needle contacting the float at all times to cut down on the chances that the float can bounce and jam the needle. It probably works much diffferent under pressure than you are thinking it would.

I would tend to go with what was in there unless the kit explains in DETAIL how the old way has been superseded. It sounds like the kit has specs for both kinds.

 

[96lt4c4]

Re: 2 barrel Rochester rebuild question

What kind of set was in there?

If you are sure the carb kit is for that carb then make sure you are not reading from an "offroading" section or something, or that the spring loaded needle is only recommended when using a higher pressure fuel pump. If you are sure the kit says use that one in all cases then follow it. The spring loading is meant to keep the needle contacting the float at all times to cut down on the chances that the float can bounce and jam the needle. It probably works much diffferent under pressure than you are thinking it would.

I would tend to go with what was in there unless the kit explains in DETAIL how the old way has been superseded. It sounds like the kit has specs for both kinds.

The kit came with one seat, but both needle inserts. It also states that Mercury Marine recommends using the spring needle. It says that the spring needle could cause a lean condition on the Merc 3.0 engines. I was just wondering if anyone has had problems using the spring needle.

This kit came from Napa and is their brand

 

[Maclin]

Re: 2 barrel Rochester rebuild question

Which style did the carb have in it before? I would use that kind.

 

[96lt4c4]

Re: 2 barrel Rochester rebuild question

Which style did the carb have in it before? I would use that kind.

It had the solid needle in it. I will give it a shot.