Tunnelstuff in Norway

Joern Markset

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• Oct 8, 2021

• #201

jaxracer said:

Very cool, excited to see this once completed. Since it is eliminating the original backplate, this should allow the engine to sit lower than traditional conversion kits correct?

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Actually it won`t sit any lower because the hight is determined by the crankshaft stickout. The tip of the crankshaft holds the flexcable in place.
So when using all original parts the engine wont come any lower.
The only difference from my prototype and any other conversions that I`ve seen, is that you won`t need to modify excisting parts.
Now if Mauro doesn`t come up with another engine design, this will be the only way to mount a CMB on an outboard lower.
I do have some sketches of another solution that will make the engine sitting a lot lower, but that requires a different crankshaft and a different disc.

 

normlee

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• Oct 9, 2021

• #202

What pipe do you run with cmb 45 outboard Joern?

 

Joern Markset

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• Oct 9, 2021

• #203

normlee said:

What pipe do you run with cmb 45 outboard Joern?

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Have not got this far as I`ve been stuck with Novarossi until now. I have SPP pipes, Irwin and Silver Bullet to try out. If it does not work I will have to come up with another solution... (which means a shitload of work...)
I have a box full of OB pipes, let’s hope there is something that will work out

 

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Alan Elzer

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• Oct 9, 2021

• #204

normlee said:

What pipe do you run with cmb 45 outboard Joern?

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Any outb pipe can be fitted to engine through my header

 

Joern Markset

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• Oct 9, 2021

• #205

I’m getting a little closer

 

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Brandon Atwell

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• Oct 9, 2021

• #206

I’ve had the most success thus far with the SPP .45 outboard pipe, limited testing however. Also have a few different Irwin Stamped pipes to give a whirl and some other creations
The RS EVO is a beast. The engine does have more weight than a standard 7.5 outboard setup, so a hull with a wider stance seems to be a must to keep corner stability.

 

Joern Markset

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• Oct 9, 2021

• #207

Brandon Atwell said:

The RS EVO is a beast. The engine does have more weight than a standard 7.5 outboard setup, so a hull with a wider stance seems to be a must to keep corner stability.

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It sure is! With the OB frontbox, the 45 EVO is apr 140 gram heavier than a Novarossi, which is quite a lot of weight when adding at the very rear end....

 

Wasted wages

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• Oct 9, 2021

• #208

Any chance of trimming some parts of weight ?
mounting pads,, lightening the flywheel ?
cylinder head?

 

Alan Elzer

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• Oct 9, 2021

• #209

Ernie Lafleur's were trimmed down and they cracked around where to belt windows were. I've ran this motor setup for 10 yrs now and the added weight helps plant the back end of hull so it flies on lower unit. The ssp nitro or quiet pipes are the best but Irwin stamped pipe is good to. The Irwin big volume pipe was 4 mph better than hoppers stamped pipe was for me. Irwin stamped pipe was even better than a big belly pipe with Irwin mid section on an Equi pipe.
Over all to me the CMB 45 RS EVO WILL OUT LAST ANY MOTOR IN ITS CLASS

 

Joern Markset

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• Oct 19, 2021

• #210

I was thinking what if I replace the flywheel with a gear and install a pinion on the fwd side? Make a t-bone hub that kicks out the starter rod as soon as the engine revs higher than the starter. Was considering a one way bearing solution as well, it has to be stainless though

Also considering making a new backplate with a 15 mm throat to fit my favourite OS carbs

 

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Joern Markset

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• Oct 22, 2021

• #211

Managed to knock out som backplates for testing. Depth is a little critical on the backplates as too much clearance will cause a leak and if it is too tight the disc will seize.

 

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Brandon Atwell

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• Oct 22, 2021

• #212

These just keep looking better and better Joern! Big fan of the new front plate, opens up a variety of carburetor options.

 

Alan Elzer

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• Oct 22, 2021

• #213

Nice work Joern. What's the bore on that carb

 

Joern Markset

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• Oct 22, 2021

• #214

Alan Elzer said:

Nice work Joern. What's the bore on that carb

Click to expand...

Thanks, Alan. The bore is 10 mm.

 

rumrunner

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• Oct 22, 2021

• #215

Will the new black plate be for sale and can it be angled for outboards?
thanks shane

 

Joern Markset

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• Oct 22, 2021

• #216

rumrunner said:

Will the new black plate be for sale and can it be angled for outboards?
thanks shane

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I will make up some parts for sale once I`m satisfied with them. Regarding angeled carb, I have already been sketching on that one, but there is some challenges. Ideally you want the carb pointing aft. Machining that part is not a problem, but the intake on the engine is angeled the opposite way (see picture) which will make the flow turn almost 180 degrees.
I have been playing with rotating the engine so that the head is pointing fwd, then there is some major challenges making room for the header. Performancewise it would have been the best option. It definitely need some tinkering....

 

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Joern Markset

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• Oct 24, 2021

• #217

I wanna make an attempt to take control over engine temperature. Living in Norway means there is 2-3 weeks with ok temperature during the season.
The idea is to make a new waterjacket with an integrated temp switch and a solenoid valve on the wateroutlet. Don`t know if it is gonna work as planned, but we`ll see.

 

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Dirk Jan Cozy

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• Feb 7, 2022

• #218

Great topic with lots of interesting info! The double nitro drive looks awesome and has some nice engineering in it as well.

 

Joern Markset

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• Jun 22, 2022

• #219

Is there any interest for the CMB RS 45 EVO outboard adapters?
I may make up some if there is buyers, but I’m not making them up just to be resting on the shelf.

 

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Shane Bastick

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• Jun 22, 2022

• #220

I'd buy one Joern