Looper advice needed

[perfmarine1]

Yes open those holes back up.

[phil blomquist]

Iam no expert in jetting for sure, but have experience with the bog out of the hole , i would keep the pull overs and try one jet size down on the mains till you find what your sweet spot is CHECKING WITH YOUR PLUGS AND PISTON FOR COLOR.This very issue took quite alot of running and checking start with 64d and do short run then check. Maybe you will find the sweet spot soon better to be rich than lean with all the work you have done to this point .

[Captain75]

Your bouncing around too much, you have to be methodical with your actions...

Start with the mains.
Purchase as many main jets as you can find,(at least 30 to start with) ream them to size and catalog them.
(Start with what you have then work down) You can always go bigger if you are going the wrong way.
Bye reamers on line, they work much better than drilling...
Get some timing equipment (ebay, talk to texasvector, he found one for less than $20) and build a set up so you can make changes and document them.
Once you have the mains figured out, build the adjustable air bleeds for the idle and off idle.
Use the timing equipment to adjust the idle then the off idle.

Its not gonna happen over night, it will take you several days to get the jetting right, but when your done, you have a motor that idles nice,
accelerates hard, and won't melt down.

Right now your just guessing.......

Jetting by time to speed (stop watch or timer) will always tell you what the motor wants, no guessing, otherwise your pi$$ing up hill into the wind again.........

Pissing up into the wind... Like before the fingerports? -
Bouncing around...
Do you mean that the increments when doing changes is too big?


These small tests I made was just a couple rough one, just to try to understand in which area/circuit I should proceed my inquiry.


I feel the main jetting is where I want it to be, 65D, maybe 66 the bottom two, that is w/o pullovers.
With the pullovers installed; 64D in upper four and 65 in bottom two.
I could probably lean out a bit more for more power, but I want it to last...


Where should I go next? Idle? Mid?
It idles just fine with the stock bleeds(#48), but it won't start w/o the fast idle lever, thats why I tried #40 instead of 48.


I want it to start by just flipping the key, at least when warm, so the Mrs won't have any problems when I'm in the water with a ski under my feet...
I got an email reply from Mr Carson who was happy to recieve my reedcages by mail, to have them cut, lapped and fitted with special 3petal reeds. Hopefully these reeds will not only add some punch, but better my starting characteristics aswell...


I will conduct one more "rough" test before I decide in which area t start fine tuning, test will include two things; plugged mids and mids leaner than stock. I'm guessing leaner is the way to go since it was screaming without airbox, until it reached the mains and starved for fuel!


thanks for your input! Please stay subscribed for further help!
//Anders

Another thing; its not so easy to get jets around here, and boats.net won't sell me any omc parts since I am outside the US. I tried to purchase a new cowling seal this summer(for my restoration) but they refused

[6Killer]

Pass......

[Lockjaw]

I think what 6 is saying is change one thing at a time, test it, and then change 1 thing again, test it, and repeat. If the motor runs good on the mains with a 65d, leave that alone, and work on the other part(s) where it doesn't run properly.

If it was me, I'd put the airbox back on, and tune it to run from there. It's not going to respond like a dirt bike on a heavy hull. And it certainly won't respond well if the bow is plowing.

[Captain75]

I think what 6 is saying is change one thing at a time, test it, and then change 1 thing again, test it, and repeat. If the motor runs good on the mains with a 65d, leave that alone, and work on the other part(s) where it doesn't run properly.

If it was me, I'd put the airbox back on, and tune it to run from there. It's not going to respond like a dirt bike on a heavy hull. And it certainly won't respond well if the bow is plowing.

Lockjaw, Thank you for your reply!
I guess he meant that aswell, I don't have any other ideas on how to do this.
I have ported and jetted at least 10 small high output twostroke motors, so I have an idea of how to do this, despite I the fact that I'm quite new to outboards.
Like I stated above these initial tests where conducted in order to identify roughly where the problem is.
My boat is quite heavy, but the 22" raker is not a unreasonable big wheel, my guess is that it should be possible to get it out of the hole w/o bogging. Slow out of the hole is one thing, bogging is another- right?
The hopeful result of this discussion is to find someone on this board with similar experiences with the same type type of 2,7looper, this person can hopefully tell me what to do.

The plowing doesn't happen before 48-49mph.

Pic to show how the motor sits in the water.

[Lockjaw]

Look if it was my motor, I'd put it back to "as stock" as possible. I think you are fine on your main jet, you said it runs good. So leave that. Put the air box on, make sure the carbs and linkage are all in sync. Get it idling properly, make sure timing is stock. Plugs good, that sort of thing.

Then identify the issue. If you think its a mid jet issue, change them, and them only. I'd go 2 sizes at a time until you find your cross over point where you go from better back to worse. Then you can fine tune it, over time. So once you are close, leave it for a few trips. Then make a change. You'll notice it more then.

One other thing. If your prop is an original raker, you might want to try opening up the vent holes, or having a prop shop cut PVS holes and use the PVS plugs merc props do. A raker 2 prop has much larger vent holes than an original raker. A little slip might get you past the trouble spot.

[Captain75]

Look if it was my motor, I'd put it back to "as stock" as possible. I think you are fine on your main jet, you said it runs good. So leave that. Put the air box on, make sure the carbs and linkage are all in sync. Get it idling properly, make sure timing is stock. Plugs good, that sort of thing.

Then identify the issue. If you think its a mid jet issue, change them, and them only. I'd go 2 sizes at a time until you find your cross over point where you go from better back to worse. Then you can fine tune it, over time. So once you are close, leave it for a few trips. Then make a change. You'll notice it more then.

One other thing. If your prop is an original raker, you might want to try opening up the vent holes, or having a prop shop cut PVS holes and use the PVS plugs merc props do. A raker 2 prop has much larger vent holes than an original raker. A little slip might get you past the trouble spot.

Hello again!
Airbox is back on.
I will leave the mains at 65D.
Only thing changed right now is the idle jetting, right now beeing #40 instead of stock #48, which is a bit rich.
When I get back from the north outskirts of my country(right now north of the polar circle), I will restore the idle airbleeds to stock, set the idle at 650 in gear and start working with the mid circuit -its got to be where the problem sits! I will try to richen the mains at first which aint gonna be easy due to the extremely small hole in the #14 air bleed. This winter I will build the kind of adjustable bleeds 6killer talked about.

I am thinking about increasing the venthole size aswell.
Do you know the actual size holes in the Raker II ?

[Lockjaw]

Just a rough guess on the vent hole size is half an inch. I think the ones in a raker 1 are like one quarter. They are small.

I don't like the idea of drilling jets though. You loose your calibration when you do that.

[Captain75]

Just a rough guess on the vent hole size is half an inch. I think the ones in a raker 1 are like one quarter. They are small.

I don't like the idea of drilling jets though. You loose your calibration when you do that.

Thank you for that measurement!
About the drilling of jets, I don't have a choice, boats.net refused to sell any oem omc/brp parts outside the US. Must be some kind of new brp policy, I've ordered alot of parts these last years w/o any problems.
My and my family are going to the US for 3 weeks around easter, guess I will have to buy some then.

[Lockjaw]

try bestboatparts.com if you have the part number.

[mackeral5]

48-49 mph is a very respectable number for a single ob boat of that size/style.

[Captain75]

48-49 mph is a very respectable number for a single ob boat of that size/style.

Highest top end was reached last week 58mph(50,5knots)
Tryin to figure the off idle jetting out in order to use the raker prop that gave me those numbers.

[mackeral5]

That's moving along pretty good..... it will be interesting to see what kind of mpg/gph numbers you see over time.

[Captain75]

That's moving along pretty good..... it will be interesting to see what kind of mpg/gph numbers you see over time.

You dont wanna know...
This thing takes about 1,5liter/nautic mile(1852meters) at cruising speed appx 30mph.
Gas price in Sweden is about 2,1dollars/liter.
So the numbers at wot isn't something I wanna know!

despite the above, The price of for example a 250 Etec or Optimax is so high, that I can burn huge amounts of gas for years, before I would have had benefit from a motor exchange
Besides this is my hobby, squeezing out as much power as I can, on my own!