Mod options

[blueskyracer]

Right now I have a Yamato 80 and a couple 102's. If I wanted to run in a mod class what are my options for classes and what has to be done to the engines to be competitive??

[JBM]

102 mod

Mike, There isn't a lot to do inside the motor. You just need a filler block/ exhaust cover, and a header and expansion chamber. I think Lee @ Machined Components has has everything you need. No height restriction in mod so we use a epoxied on nose cone on the gear foot that has a water inlet. We need more mods on the west coast, and its a great ride... GitRdone

[Dave M]

Just Add Pipe

All that is needed to make a stocker into a Mod for the Yamato is a pipe and filler block. The last I checked, the rules do not allow you to do much inside, other than what the stock rules allow, which is a lot.

Lee Tietz makes a dang nice set up to get you going, on the high end for price, but his work is awesome and simply bolt on. His pipe is very competitive as well.

One nice thing about the pipes, you can interchange stingers in the end of the chamber to accomodate different size courses without changing actual chambers. But then, it is also fun to mess with different pipes to get that edge. If you are a welder, they are not to hard to make, but it takes a lot of cutting and welding. The initial angles and diameters are very important. I would buy a used one try it and go from there, or buy Lee's set up and if you wanted to play, make one similar and change some things and go from there.

If you get the winter blues, which you might in Montana, this will give you a lot to do and is fun. Don't need to heat the shop up as warm either !

Speaking of off season fun, do you do any duck hunting there in Montana ? I heard it is great there and would like to try a trip out there sometime.

[machinedcomp]

Yamato 102 Mod Parts

Mike,

I have a 102 expansion chamber setup on the shelf. It includes exhaust cover and filler block, header and pipe. You will need to fabricate your own pipe support. $500.00 + UPS.

[blueskyracer]

Mike,

I have a 102 expansion chamber setup on the shelf. It includes exhaust cover and filler block, header and pipe. You will need to fabricate your own pipe support. $500.00 + UPS.

I can build almost anything out of wood but metal not happening in my life time

[blueskyracer]

[Speaking of off season fun, do you do any duck hunting there in Montana ? I heard it is great there and would like to try a trip out there sometime.[/QUOTE]

Dave, not sure about ducks since I have never duck hunted but deer and elk hunting is fabulous and rifle season starts the last week of October and ends the weekend of Thanksgiving.

P.S. Don't you just love stock motor rules.

[Mark Monkres]

Please explain to me the filler block

[26V]

filler block

when you modify an outboard motor to accept the pipes you have to block the original exhaust passage and redirect the exhaust to the exhaust pipes.

[Mark Monkres]

Thanks, Can Do That With A Motor That Exhausts Thru The Prop?

[Dave M]

Yes

Thanks, Can Do That With A Motor That Exhausts Thru The Prop?

That is why you put a filler block in, it directs the exhaust to the desired location of the pipe you are going to put on. It is a simple piece of metal, usually aluminum that is has holes in it to match the opening on the exhaust port side. The openings are typically oval in shape, and you simply glue ot silicone this part in, and then bolt on the side plate, elbow and pipe, exactly as Lee has shown in his picture. Very easy process if you purchase the filler block already shaped correctly. There are normally curves on the part to match the cylinder shape it is sealing.

This is true on most mod engines, however, there are exceptions. Some of the A Mod stuff and B mod stuff have a toliet bowl type exhaust that exits down. In addition, majority of exhausts on a 850CCM engine exit down as well.

Hope this helps you.