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Rallyspitman
09-29-2012, 03:26 AM
Just winterising my 91 prostar today, and decided to chase the threads in the exhaust headers. They have needed done for years and are now so bad I'm worried that I'll not be able to get the plugs in next spring. They do often leak and I tighten them up so tight I'm worried about stripping the thread.

Need the plug size and thread form if anyone knows this???

I went to the lake last night to warm up the oil for draining, it was probably the best conditions this year, glass like no wind and only a little chilly. Sadly I was on my own, so just ran up and down the course pretending. Damn!

Miss Rita
09-30-2012, 10:06 PM
should be 3/4" NPT. There is no pressure in the exhaust system to speak of, shouldn't be leaking. When you get new plugs put some pipe dope or teflon tape on the threads to seal them. It wouldn't be a bad idea to put some grease on the newly-chased threads in the manifolds to help prevent rust.

glgisler
10-01-2012, 03:58 PM
These large pipe taps can be rather pricey. I found one on Ebay - LucTool2008 for $11.45 and it worked fine. No markings, probably made in China, but I didn't figure to be using it much.

The other thing that I did is get the easy drain valves from DIM - course, where I live, we get good weather many times during the winter, so we typically winterize/dewinterize several times during the season. Nice thing about the easy drains is that you're not removing/reinstalling plugs anymore.

Gary

mcparadise
10-01-2012, 07:51 PM
These large pipe taps can be rather pricey. I found one on Ebay - LucTool2008 for $11.45 and it worked fine. No markings, probably made in China, but I didn't figure to be using it much.

The other thing that I did is get the easy drain valves from DIM - course, where I live, we get good weather many times during the winter, so we typically winterize/dewinterize several times during the season. Nice thing about the easy drains is that you're not removing/reinstalling plugs anymore.

Gary

from a previous post:
FWIW, I installed the easy drain set from skidim (link below). A little expensive, but nice product and they work well using clear tubing run to a bucket sitting under the bildge drain plug opening.

http://www.skidim.com/products.asp?dept=1044

88 PS190
10-01-2012, 08:16 PM
NPT is a tapered thread, so you shouldn't have an issue stripping it, also the plugs tend to be brass/soft, and the manifold steel-hard.

So the plugs usually will wear off the thread before the holes strip out.

If they're leaking give them a wrap of tape and go easy on em.

Worthing skier
10-07-2012, 12:07 PM
Hi there

Nice to sea another Prostar owner on this side of the pond posting here ,
Had the same issue with mine ,so i just got a couple of brass blanks from my local plumber shop , seals much better as you are not relying on just the threads to seal it .

Kevin

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