What size tap do I need for ….

[huntleybill]

I have a mid 70’s Evinrude 2HP motor that the idle needle threads on the carb side are damaged and I can’t screw the needle in. Can someone please tell me what size tap I need to chase those threads?

Thank you
Bill

[Mumbles]

If you can wait a while I can measure one when I get back later.

[huntleybill]

ok… waiting

[Mumbles]

Sorry. Got home late. Will check first thing in the AM.

[A Hoskins]

Most tap ad die sets have a thread gauge for every size in the set. They are also available separately. Measure the needle.

"Fox News" isn't.

[huntleybill]

Thanks gbm, but that is only half the dimension size. I “think” it is a 40 threads per inch but how big is it?

[Mumbles]

Dang it Bill but I’ve been searching and can’t find the carb. I know it’s here somewhere as the motor is fully rebuilt and waiting for paint.

I’ll keep looking until I find it. Sorry for the wait.

[Mumbles]

I looked all over and still can’t find that two horse carb but other ones from that era, such as 9.9 and an early 80’s 4.5 I found, have a 1/4 X 28 thread on the low speed needle. That’s a common SAE fine thread so no special tap or dye needed.

[huntleybill]

Thanks mumbles but I have a 1/4-28 and it is too course. I have a 4-40 tap that the threads fit and the shaft of the needle is 1/4″. I have never heard nor can I find a 1/4-40 tap. What am I missing?

[Mumbles]

I posted some special taps and dies used on OMC motors over on the Facebook site and a 1/4 X 40 was one of them. I had to order mine from a tool house in Vancouver. Grainger or someplace like them might be able to supply them or maybe on Ebay.

If you Google that size you should get some hits.

• This reply was modified 4 years, 8 months ago by Mumbles.

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