Right angle gas mono jig

Intlwaters

Help Support Intlwaters:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Mike Hughes

Well-Known Member
Vendor
Joined
Feb 23, 2003
Messages
4,150
While I was doing a refurb on a gas mono that was gifted to me, I came up with a jig to drill the rail walls. It is very helpful in aligning the mounts the same on both sides. Which was the problem with the refurb job.

Things were not lining up close enough for my taste. So filled them in with epoxy and started over. Here is a shot of the item I came up with. You just clamp it to the side of the rail and drill it out with a 90* drill bit.

20220304_183237.jpg



20220304_183256.jpg


I orginally bought some short bits on amazon. See below. The problem I was having was nothing really fit with what the bolt i was using. It was either too small or too sloppy.

20220304_183315.jpg


That is when I came up with the idea to make my own. I had done this in the past for a work project with a piece of round stock metal that I machined a 1/4 hex on the end. Then just had a set screw to mount a short bit in. Since I could not find what I did with that tool, I need a newer and easier way to build one. I dug thru and found a chamfer bit that was broke that had the hex already (just like the unbroken one in pic). I was able to remove the broken bit and drill it out all the way thru with the size I wanted. Then cut the drill bit down some to shorten it. Then took some loctite 638 and glued it into the hex bit. Now I have a #18 short hex bit to drill all the motor mount rails till the cows come home.

20220304_183413.jpg
 
Last edited:
I have found that using the exact engine/engine mounts/rubbers for your template you can't go wrong.

Tape the rails with wide blue tape then set engine in place. Once you have it where you want it you simply take a sharp pencil and trace around the rubbers. Then you center a #8 X 1" fender washer in your marks and mark the center of the washer. Pilot dril little hole then 1/4" or use brad point 1/4".

It gets them so close you can literally thread your bolts dead into the rubbers exactly where they were had one hole be off even one iota and engine comes out exactly where you had it when you marked it EVERY time.

Done hundreds with this technique and never had a single one be off by any amount whatsoever.
 
I run the seaducer style mount. That is the way these rubber iso mounts are designed to be used. It makes motor swap real easy. It requires a angle plate bolted to the rail. The front plate is 1 inch offset higher to the rears. This mount is difficult to do it the way you suggested. It is really easy to layout on a jig thou. Hence my idea.
Mike
 
Oh yes oh boy. Didn't pick up on that. Done plenty of that style too. Simply place the assembly and trace the bracket outline. Then hold the loose bracket to traced line. Been the template route before and it seems to add error every time. Use the actual assembly and after drilling the bolts slip right in their holes every time.

Your templates do look nicely done and bet they do a fine job for you on those mounts. .....but. Lol.

Gotta get away from those junk mounts first of all. Lol.

Very familiar with that style. Yikes. We used those 20 years ago as Speedworld EZ mounts and Top Secret mounts. They are a gimic. Everyone used that style at one time. Now almost no one uses them. Every mount is quick change today. Loosen four nuts and it is out.

I know some like the way you can drop to engine down low with them. That is true you may get it lower in the hull but it isn't a sailboat and doesn't need to be slammed. Many monos run better without the engine dropped as low as it will go. You don't need a heat race mono to be self righting. You want it as comfortable up on it's side as it is on the bottom.

20 years ago every boat used them. Fast forward to 2022 and out of 300 boats you are not likely to find a single boat with a set in them today.

The vertical rubbers allow to much engine movement and cable likes to eat the stuffing tube. The tiny 5/8" rubbers fail in most wipeouts and when pull starting. The brackets love to dig in the rails. Best of luck.
 
Last edited:
Back
Top