Thread type

[Gilby]

Hey guys, I have a question on thread type. During my restoration project I put a new transom in. It must be about 1/2" taller than the old rotted one was. This is where my problem lies. I have a new johnson livewell pump and the flat portion of the intake does not mate up to the transom. The hole in aluminum is just below the wood but not enough clearance to mount pump flush. So my thought was, since I happen to have a thru hull fitting that is long enough to go through the hull and clear the wood, I would just get a barbed fitting to screw onto the pump and therefore just need a piece of 3/4" hose to attache the two. The problem is, the intake on the pump is a very fine thread and I have yet to find a fitting to screw onto the pump.

Does anyone know what type thread is on a johnson pump intake?

This weekend I bought a chunk of hose that could go over the intake threads and a reducer to fit down to the 3/4" intake but this is my last resort as the hose would not fill the threads and would therefore have a leak most likely.

Thanks for any support in this

 

[Billy H]

Take your pump to a quality plumbing supply house ( not a big box store) and see if they can set you up with something that will work.

 

[Gilby]

I have to run up to town tomorrow anyways so I will take it with me to see what I can find

 

[MDCrappie]

If you are talking about the tube that is supposed to go thru the transom and have a nut on the outside those are usually 3/4"x14 thread.

 

[Gilby]

Yes, that is what I am talking about. I knew it was 3/4'' just wasn't sure on thread pitch. Thank you!!

 

[kazzer]

Hey guys, I have a question on thread type. During my restoration project I put a new transom in. It must be about 1/2" taller than the old rotted one was. This is where my problem lies. I have a new johnson livewell pump and the flat portion of the intake does not mate up to the transom. The hole in aluminum is just below the wood but not enough clearance to mount pump flush. So my thought was, since I happen to have a thru hull fitting that is long enough to go through the hull and clear the wood, I would just get a barbed fitting to screw onto the pump and therefore just need a piece of 3/4" hose to attache the two. The problem is, the intake on the pump is a very fine thread and I have yet to find a fitting to screw onto the pump.

Does anyone know what type thread is on a johnson pump intake?

This weekend I bought a chunk of hose that could go over the intake threads and a reducer to fit down to the 3/4" intake but this is my last resort as the hose would not fill the threads and would therefore have a leak most likely.

Thanks for any support in this

If you have a micrometer/accurate measuring device, measure the OD of the tube, and then count how many threads there are in one inch. I'm not sure what threads would be on a Johnson, but it's likely made in USA so that would narrow it down. There are lots of thread charts on line.

 

[MDCrappie]

I figured it out years ago when I purchased a screen strainer for one.

https://www.amazon.com/Stainless-Steel-Mesh-Strainer-Livewell/dp/B0BZP5DSY1

 

[flatheadsteve]

With any plumbing type fitting or hose on a boat if you have a local ag equipment dealer nearby chances are they have the fitting/hose etc in stock ....ag sprayers use lots of the same stuff

 

[MDCrappie]

With any plumbing type fitting or hose on a boat if you have a local ag equipment dealer nearby chances are they have the fitting/hose etc in stock ....ag sprayers use lots of the same stuff

The problem I think he will run into is that most of those fittings are tapered. His threads are straight. About the only 3/4" straight thread fittings I've seen are FGHT. (Female garden hose thread), which are more course.

 

[flatheadsteve]

The problem I think he will run into is that most of those fittings are tapered. His threads are straight. About the only 3/4" straight thread fittings I've seen are FGHT. (Female garden hose thread), which are more course.

They make adapters to change the fght to fine thread...if his is indeed 3/4" npt that's what all the little blue hydro roller pto pumps have for outlets

 

[MDCrappie]

They make adapters to change the fght to fine thread...if his is indeed 3/4" npt that's what all the little blue hydro roller pto pumps have for outlets

His thread is straight (parallel), 3/4" npt is tapered. I think he needs a female in 3/4-14 NPSM

Something like this......

https://www.mcmaster.com/5365K33/

 

[MrGiggles]

Why not trim the wood?

 

[LDUBS]

I agree with @MrGiggles ' suggestion.

If you want to find adaptors and are not sure of the thread, take your pump to any decent hardware store. The threads on your pump are pretty standard and you will find the fittings you need.

 

[timm gage]

Hey guys, I have a question on thread type. During my restoration project I put a new transom in. It must be about 1/2" taller than the old rotted one was. This is where my problem lies. I have a new johnson livewell pump and the flat portion of the intake does not mate up to the transom. The hole in aluminum is just below the wood but not enough clearance to mount pump flush. So my thought was, since I happen to have a thru hull fitting that is long enough to go through the hull and clear the wood, I would just get a barbed fitting to screw onto the pump and therefore just need a piece of 3/4" hose to attache the two. The problem is, the intake on the pump is a very fine thread and I have yet to find a fitting to screw onto the pump.

Does anyone know what type thread is on a johnson pump intake?

This weekend I bought a chunk of hose that could go over the intake threads and a reducer to fit down to the 3/4" intake but this is my last resort as the hose would not fill the threads and would therefore have a leak most likely.

Thanks for any support in this

go to ace hardware, they may be able to thread anything you need