Blaster Blaster B1 head pipe clearance

Finally putting my B1 back together installing new FPP mani and head pipe. Much to my dismay head pipe is pushed up against the the hull, with pressure. It’s right before the coupler with the chamber. Ground on the hull , any more and I’ll be doing glass work. This is a suuupper clean b1 so I would like to no do glass work, but I guess we will see? I ground a little on the head pipe. Question one: how much can i grind before entering the water jacket?
Question two; how much clearance do I need? 1/8, 3/16,or 1/4? I attached some pics. The circled sharply is where I would need to grind?309EF873-C69A-41D4-AA3D-B6216FE0A07C.jpegEB007243-6553-468A-99AD-79471D9B59A7.jpeg
 
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fx1mark

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Factory pipe designed this pipe to fit without any grinding. Something is wrong if it is not fitting. Is this a 61x/62t motor? Is the motor properly aligned? What gaskets are you using? I sure as hell wouldn't be grinding on my factory pipe.
 

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Factory pipe designed this pipe to fit without any grinding. Something is wrong if it is not fitting. Is this a 61x/62t motor? Is the motor properly aligned? What gaskets are you using? I sure as hell wouldn't be grinding on my factory pipe.
B1 Blasters are hand layed fiberglass, so each one is different. As far as motor alignment. If you knew what you were talking about, you would know that the pump goes in the ski first and then the mid shaft is aligned to the driveshaft and the motor is lined to the mid shaft, so the motor ends up wherever it needs to be and sometimes it’s not where you want it to be. If you do all the correct shimming of your pump and midshaft it sometimes shifts the motor over to one side or the other. If you’re unlucky enough to have one like mine where it shifts the motor over towards the exhaust side you are going to have clearance problems. This is a fairly common problem with the b1blasters. I’ve been building Jetski‘s for over 25 years I know exactly what motor and pipe is supposed to be going in this Jetski. Factory Pipe built Blaster mod B pipe’s to be as large as possible and perform well. This means pushing the limits of size and if anything is slightly out of whack there’s gonna be clearance problems. I am looking for somebody who has experience with this exact problem not somebody who is lucky enough to not have a clearance issue thanks. I’m running 62t/61x. I’m pretty sure 61x/ 62t would run like a bag of crap
 
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fx1mark

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Location
Alabama
I have been building jet ski's for more than 35 years. I was asking if it was a 61x or a 62t motor. Good luck.
 

Mike W

Infidel
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Location
North Florida
Had the same problem with the last B1 (96 wT cases) I had. Tried everything but ditched the pipe in the end because it almost rubbed a hole through the hull.
 
Would taking a little off the mating surfaces (cylinder exhaust, manifold to exhaust ports, manifold to header, header to manifold) give you the clearance you need? Doing all surfaces would bring your exhaust closer to the engine and drop it lower a touch. Also, maybe making your gaskets from thinner material would help a little.
 
How straight is the Pump Driveshaft? Max Shaft Run-Out is 0.3mm, worst case maybe 0.5mm. A bent Driveshaft could affect the alignment.

I'm wondering about how "centered" the Midshaft is since the 3 Midshaft Bolt Inserts are installed in the Bulkhead at the Factory and that means that the Midshaft has a fixed location with no possible adjustments(?). I remember the Midshaft has a Locating Pin. So Midshaft is a fixed Reference Point.

What changed, besides the New Exhaust System?

Did you reuse the original Pump Shimming and Alignment or did you start from scratch? Same Pump or different Pump?

Is it an Aftermarket Midshaft (e.g. WSM) or an original Blaster 1 OEM Midshaft? Maybe try a different Midshaft?

The Coupler Alignment does have some allowable play that might help: 0.6mm max Hi-Lo and Side-Side, and 2-4 mm forward and back allowable Clearance.

Jet Maniac says best to align Couplers without the Rubber Dampener.

Cartooon-Rigging-Flange-Alignment.gifpiping flange alignment misalignment.png
 
To all, I had the same thing happen to my Blaster B pipe for a 62T engine in it, the Factory Pipe would rub the side and I could not get the Engine correctly aligned to the midshaft,
Then I realized I had used the Factory Pipe Exhaust B pipe manifold I had for the Superjet Hull, instead of the Blaster Factory Pipe Exhaust Manifold I had on the work Bench, the Superjet manifold is about 1/8" to 1/4" thicker at the base and it does not allow the B pipe fit in the Blaster hull, see pictures, I swapped them out and the Factory Pipe fit perfectly
 

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fx1mark

Site Supporter
Location
Alabama
To all, I had the same thing happen to my Blaster B pipe for a 62T engine in it, the Factory Pipe would rub the side and I could not get the Engine correctly aligned to the midshaft,
Then I realized I had used the Factory Pipe Exhaust B pipe manifold I had for the Superjet Hull, instead of the Blaster Factory Pipe Exhaust Manifold I had on the work Bench, the Superjet manifold is about 1/8" to 1/4" thicker at the base and it does not allow the B pipe fit in the Blaster hull, see pictures, I swapped them out and the Factory Pipe fit perfectly
That's interesting. I would think if you only owned the thicker manifold you could have it machined down to get the pipe to fit.

edit: I just measured my manifolds. the fx1 is 9mm thick in that area and my waveblaster is 12mm.
 
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