Yamaha Pump-to-hull bolt size - help solve a mystery!

[GRiN]

Ok, so my squarenose, my rickter, and all the raiders and ventures I've ever parted out ALL have M10 fine-pitch bolts holding the pump to the hull.

Last week I ordered some socket-cap style pump bolts from Rad Dudes and the bolts I recevied are M8... Rad Dudes is being super accommodating and has ordered me the bolts I need, but now both of us are left wondering - are we going crazy?!?

They have checked their records and have essentially little to know supplier purchases of M10 bolts, but they sell their pump bolt kits all the time.

I just got confirmation from another buddy locally that his ski uses M10, so I figured I'd ask you all...

What size are your pump-to-hull bolts, and what year/make is your hull.

Thanks!

 

[WFO Speedracer]

No idea on the year , the hill ID plate is broken off but it is SN and it definitely has 10mm bolts

 

[Roseand]

Some am hulls use 8mm bolts which gives you extra room for pump alignment without having to hog out your expensive pumps and trim.

 

[Big Kahuna]

Most am hulls use 8mm bolts which gives you extra room for pump alignment without having to hog out your expensive pumps and trim.

I tried to look back on my build thread, I remember having to order special bolts for the Pump.

 

[fastgtfairlane]

m10x1.25 is the correct thread for oem. same as the case bolts. i may or may not have case bolts holding my pump to the hull. my superfreak had some standard sized t nuts glassed in when i got it. i removed them and glassed in some oem brass nuts.

 

[GRiN]

m10x1.25 is the correct thread for oem. same as the case bolts. i may or may not have case bolts holding my pump to the hull. my superfreak had some standard sized t nuts glassed in when i got it. i removed them and glassed in some oem brass nuts.

I DEFINITELY have case bolts holding my pump to the hull lol but that is because I needed big shims for proper alignment and I added a Thrust tow-hook so I needed longer bolts.

For everyones collective information, Rad Dudes says they will be stocking the M10 socket cap bolts moving forward. I believe HSI offers them as well.

 

[JetManiac]

Tigercraft hulls use M8 for the pump to hull.

All Yamaha OEM SJ/B1/other models use M10 fine thread.

Most a/m hulls use the same, except SuperFreak which use coarse thread and a few other oddball hulls.

 

[G-Body]

All of my superfreaks have use the M10 fine thread bolts.

 

[Storbeck]

It's really not "fine thread" vs "course thread" it's JIS vs DIN/ISO. Japanese stuff is built with fasteners that are to the Japanese JIS standard which says that a 10mm but has 1.25 pitch threads and a 14mm head, where most European and American stuff uses the DIN/ISO standard that says a 10mm bolt uses 1.5mm pitch and has a 15mm head. There are a few other differences (12mm vs 13mm head on m8 bolts and I think the pitch for 12mm bones is different too).