Johnson "70mod"

[hupiveneilija]

Back together! Waiting for going back to the boat and startup. Have some work with the boat because transom has been done completely new and also have to blueprint the hull.

Has anybody tried those newer 70hp carbs with black plastic top? Are they worth nothing compairing to the older version?
Also went older pack with appropriate stator. Should be unlimited.
Really exited to see how it works, or dont😬.

[filthy phill]

Be interesting to see if it goes with that cylinder head, from the tiny size of combustion area it looks very strange .

have checked to see how many cc it is ? and what is the cranking compression now ?

will you run the engine on the stand for a while before putting on boat to run it in nice and slowly ?

[hupiveneilija]

That is the boat where the 70mod is going to.

[filthy phill]

that should be good for about 50 to 52mph with your mod engine. at around 6500 rpm with a good 23 pitch prop.

what make is the jack plate ? or did you make that yourself ?
i have never seen one the same as that before.. looks realy good.

the boat looks familiar, pretty sure i have seen these in the uk too, they look nice and sharp, plenty of rails so should be good in the rough stuff.

looks like its going to be a real good offshore racer, plus looks good even in the garage.

[zul8tr]

If you had a pad on that deep Vee it would run faster and be more stable (minimal lateral rocking) at speed. The right pad dimensions will reduce water drag. The pad would require a higher engine set since to do it would remove some of the bottom Vee.

Details here on why a pad:

http://www.aeromarineresearch.com/pu...B_jun2011.html

complete article available from Jim Russell see lower left of article.

[hupiveneilija]

If it is that slow, then i have to put stock motor back to the boat. It went 57.5mph with it.

[filthy phill]

if you got 57mph with the boat and motor why on earth have you stripped it down ?

what speed and rpm are you expecting to get from the boat motor combo ?
and what size prop ?

[hupiveneilija]

I dont know, for fun? Or maybe i want to try if i can make my motor rev higher and go faster. Go figure..

[filthy phill]

is the boat an Argo 16 or Argo 15 ?

[hupiveneilija]

Its 17. By the way, jackplate is Panther450.