Here goes...

I am pulling 68.7 at 7230 rpms. I am running (right now) a 13/19 Solas. I just got the boat through break in (motor rebuild).

I have 2 questions...

How do I go about tuning the carbs?? My carbs are set at 1 1/2 on highs and 1 1/4 lows. Should I start with the lows and tune the hole shot, or tune in the highs for top end? The more I turn them in, the leaner and faster I get, right? (within limit)

Next, I am turning 7230 with a 13/19.. What will a stock 14/20 do to my speed and rpms? Should I tune the boat after swapping props?

All comments are welcome.

Thanks.

Properly tuning a motor can be a night mare but also simple with some basic understanding.

You should adjust the carbs in the order of...

#1 Low speed adjuster
To adjust a smooth idle

#2 pop off pressure
Just off idle to 1/4 throttle in conjuction w/the low speed jet

#3 low speed jet
Just off idle to 1/3 throttle

#4 high speed jet
1/3 to 3/4 throttle

#5 high speed adjuster
3/4 throttle to wide open

The reason for adjusting the circuits in this order is because several circuits contribute to total fuel delivery to carbs

Not many people do it this way as far as I know because it's to complicated and takes to long soooo.....

Go out and warm up your boat ....nothing will happen as long as you dont pin it forever or put to much load on it....meaning dont make hard turns at high speeds untill you tune it

Cruise and set idle.....
go run it for a minute varying you throttle speeds,come back and idle for about 30 secs,,do a take off run....no need to reech max rpm just go to about half then stop and do it again....

If it falls on its face meaning you expect it to go and it dies it's lean.....
If it hesitates it's rich.....
"Going in on the lows and highs leans out the mixture turning out the screws richens it up"

Tune accordinly to your boats reaction by going in or out by a 1/4 turn then 1/8 of a turn for fine tuning. It sucks because there are 3...
Then ride it and adjust idle again if it changed.
Then idle again for 30 or so secs....take off and see if it goes,, lows might need one more adjustment.

Since your breaking in the motor I assume it's already running rich. When tuning make sure the break in fuel has been used up and your running normal fuel and oil.

Run the boat for a minute or two at 1/2 to 3/4 throttle as to where this is where the high speed jet is functioning. Then cruise a little more than half throttle for about 1 minute and punch it....If the engine hesitates the carb is lean, if the engine takes a second or two to clear out and then accelerates the carb is to rich...if ethier should happen rejet according to what happended and start over...Most people wont rejet they just turn the screws in to help out this problem....but will never really get rid of it all.


The high speed adjuster is the last to adjust controlling 3/4 throttle to WOT

Maximum Fuel flow is achevied at 3 turns out.

If your jets are right this is where the plug chop comes in...Make sure you havent messed with the high speed screws ....because you should start rich here. 1 1/2 is a good place to start ...if you want go out and extra 1/4 turn if you feel uncomfortable about getting ready to ride the **** out of your boat.

Warm up your boat come in and change your plugs to a new set and take off and run it for about 2 to 3 minutes at least. Not going under 3/4 throttle
Go ahead and ride the p.iss out of it ..then do a 10 second WOT striaght run and let off and kill the motor....

Have your Spark plug wrench with you, pop your seat off pull the plugs and see if there nice and brown...if they are your done...if there dark you need to come in on the high speed screw a 1/4 turn at a time

If you have a good tach and your tuning with that thats easier because you dont really need to do the above part I just listed. But still do it after a hard ride for a few minutes and just take a look at your plugs. It's a good way to see what your motor is doing.

Start by doing a WOT run and note max rpm on tach.
Turn out 1/4 turn run it and note rpm....

Depending on what happens if rpm goes down then you can say that your ready to come in some on the high speed screws.
Go back in a 1/4 turn to where it was and run it and note or check to see if it was close to where you started,
then in a 1/4 and run it noting your rpms each run.
If it goes up turn in a 1/4 turn untill you reach a max rpm....if it starts droping go back out a 1/4 turn and you should be done. If you want to feel a little safer turn the high out 1/8 of a turn.

I like my carbs at about 1 to 1 1/4 on top and 3/4 to 1 out on lows I also run my rear cylinder about 1/8 to 1/4 out more than the front two. Others do this too...The rear cylinder tends to run a little warmer

Then the rest of the tuning would be for weather and elevation
If you want to get critical tune each carb using the tach and adjust each one seperate. Always start by going out a 1/4 then in untill max rpm is reached then on to the next carb then the next.

I would print this and short cut it on a 3x5 and put it in a tuning box

A tuning box should consist of...
Some tools
Plugs
Jets
Zip ties
Pad of paper and pen to note what you did and where and what was used .....prop,, grate,,ect....

It just gives a good baseline and great for referance

As far as props tune for each prop used ...usaully just low speed screws and high speed screws

the 13/19 should give better bottom and mid with good top
14/20 a little loss on bottom or mid but better top.

Also depends the 13/19 might spin more than a 14/20 out of the hole ....Others will have more experaince on the props as I mostly work on tripple pipe boats

Props also depend on how you like to ride and conditions you mostly ride in. If you like a boat that hits off the bottom and keeps speed thru turns and in chop a smaller prop is better.

Others will chim in of course on the props and experiances with them.

This is the long way for tuning but you learn alot by doing it this way and will get better and quicker at it....and know what to look and listen for....good tuners can hear a boat running rich ....listening is important

hope this helps and didnt make things worse...

Later Jonny5

This message has been edited. Last edited by: jonny5,

Man J5,

You could added some more details!

I have an idea you covered it........

Yaaa I know,, I was very bored the other night and no one was around and I was up late so I started writing...and away it went. I didnt seem that long untill I posted it...then it came up and I was ohhhh crap...
OH well....it's good info though....



J.5

Hey Jonny read your part about props. Got a question on a 1300. Heres the deal, I ride in swells and surf, So I want my boat to have tremedous pull on the botton end and mid. Right now I have a Riva 13/20 SB, PPK and rest of boat is stock(don't pay attention to botton of page). I also don't want to do the JW mod, or get into the engine to much because of warrnty issues. Do you see anymore options for me on this. It feels like a dog out of hole. Thanks

Jonny5,

Thanks for all the detailed info...

If I get any more warm weather, I'll have a good base to start with.

I am stil open to opnions on the prop question...

Thanks..

J5 - great post on tuning - best I have seen

on props I thought J5 covered it well as well
13/19 - best low end prop
14/20 - good top end, 1 - 2 mph faster than 13/19 (or 13/20)

and don't forget a Nujet 6.5, another great prop - good mid and good top end, 1 - 2 mph faster than 13/19 (or 13/20)

FL Air - you might consider getting a head to raise compression, if you ever needed warranty work you could put the stock head back on - that ski shouldn't be a dog out of the hole - if you want to spend some $$ you might consider a Skat pump with a Skat 13/19 swirl impeller - look for one in good shape that is used

This message has been edited. Last edited by: Philip_GPR,

P_GRP,

Thanks, for the clarification... I have a 13/19, 13/20, and a 14/20...

I am really looking for the RPM loss from going to a 14/20 from a 13/19... I want to know how many RPMs I may need to make up.

Thanks Philip_GPR for info. I guess what I'm getting at is the 13/19 to little prop for a 1300? Has anyone tried this out there? Also could I just add a head and nothing else and get a great kick in the paints ski?

FL AIR in my opinion a skat R prop or swirl would be best, a little more compression is always helpfull too.

I have never really liked the solas props except for speed and cruising but as far as a good prop for good bottom and mid I like the R prop from skat trak. The skat wont have as much top as a solas but is better for what your telling me.

I also have a prop it's new 14.5/19.5R prop It's a custom pitch that I had made up, never got to use it So I cant really say what it will do but I really want to find out but dont have a boat to test it on.

Are you running a stock nozzle on your 1300...85mm??

That info will also help in finding a good prop..

This message has been edited. Last edited by: jonny5,

jonny5 I run a stock nozzle for now. It's funny because we have had flat water ALL SUMMER. And I had my boat set for chop (Sponsons down, Top load grate). Now I can't find a pice of flat water.....so would like to set for chop/surf. Again thanks for all inputs

Wow, just saw this from the other thread. Johnny, can I archieve this on my website. Great stuff.

Mark do as you please ...it's no secret....

If you want to modify it to a shorter format go head....because I guess I could have made it a little shorter...