installing crankcase pulse nipple

[jetskiron]

Can I please get some tips on installing a crankcase pulse nipple? I have a 97 roundnose 701 superjet. I am installing a set of 44mm carbs and each has a carb pump with pulse nipple. The oem superjet has only one pulse line from the crankcase at the rear, however there is a slot at the crankcase front to add a second pulse line. I would drill a 15/64 hole and press in the oem brass nipple, but I am afraid I might screw it up in the process of pressing or tapping it in. The brass nipple is very thin walled.

 

[Little_Franny]

I just did one and used a 1/8 npt fitting, took the intake off and shoved a bunch of shop towels down into opening to keep any shavings from getting into crank case, drilled and tapped, installed fitting, carefully removed towels vacummed up the mess. good to go

 

[Wizards Powersports]

Adding the OEM fitting is easy, just do as you describe above after test drilling a piece of scrap aluminum and making sure there is enough interference. Then put some red Loctite or similar on the nipple and tap it in with a block of wood and a hammer. They are sturdier than you think and as long as you use common sense you'll be just fine!

 

[Philip Clemmons]

Just be sure not to go too big. Practicing is a great idea, and I like to use a few sizes smaller on the bit. I go up a 1/16 at a time and check fit each time. Sometimes a wandering hand can make it larger than the bit you're using, so if you step it up and check each time, you'll be fine.


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[Quinc]

Just be sure not to go too big. Practicing is a great idea, and I like to use a few sizes smaller on the bit. I go up a 1/16 at a time and check fit each time. Sometimes a wandering hand can make it larger than the bit you're using, so if you step it up and check each time, you'll be fine.


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Good advice right there.

 

[feartheride]

Yes starting with a smaller drill bit and stepping up always minimizes the chance of the drill bit cutting to big, also good to do when cutting threads for heli coils or time serts .. Make sure the drill bit has never been sharpened by hand either or the bit will likely cut larger hole..

 

[MikeyB]

I used npt fittings on my cases since one of the oem fittings popped out.


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[jetskiron]

Thanks All! Well I ended up with a slightly out of round hole and pressed the nipple in. I used green Locktite 640 sleeve retainer. The tube of locktite was probably 10 years old so it may not work. It requires 24 hours to reach full strength. So I will check it tomorrow. If it is still liquid, I am thinking of pulling it back out, cleaning it and reinserting it with an epoxy like JB Weld?

 

[txsuperjetfreak96]

Used jb weld when I Added second pulse fitting

 

[jetskiron]

Ok Superfreak, thats exactly what I wanted to hear. That Lokctite green 640 is still wet a day later. Maybe because it is an old tube? Anyway, I am going to pull the nipple out and clean and reinsert with the JB Weld. Supposed to be good to 600 degrees. I assume you have had no problems with it. Will advise.

 

[txsuperjetfreak96]

I haven't run it yet others have done the same

 

[jetskiron]

Thanks All! I used the JB Weld full strength and it worked well today at the lake.