JAE 21

[John Seybold]

I'm have some trouble getting my rigger running. It's a JAE 21 with a NovaRossi 5 port with Glenn's carb modification. I have a Sholund 1450 prop, pipe at 9 1/4 and 90 on the Boris flow meter, also running an O'Donnell blue plug. The boat starts fine and sounds good on land, once she hits the water its out in about 1/8-1/4 lap. I bring it back in and again it starts right up, however I get the same results. I tried to richer the needle, then I tried leaning it down and still no luck. I checked fuel lines as well as the motor for air leaks and couldn't find anything. I know it could be a number of things, but where would you start trying to figure it out. To much prop? Pipe length off?

Thanks,

John

 

[shoboat]

John,

How much cup on the 1450? How big is the diameter?

Pipe is way long try 8" to 7.5". What fuel %?

Let Us Know?

Mark

 

[ken turmon]

Are you sure it isnt a warn piston/cylinder. I,ve had cars do that. They start up and run but when they are hot and under load they lose power and die. Bye the time you retrieve it, it has cooled down enough to start up and do it all over again. just A thought.

 

[ALLAN YUEN]

depend on what kind of pipe? and measure shim gap?

 

[Rene Danner]

Where is your head clearance at, My 5 port pulls a H-7 no problem with a pipe set at 7 7/8th (s-pipe).Also what percent nitro are you using?

 

[Duck899]

1450 is too big to get started with. Try a 1445 and get the needle set, pipe as suggested with 50% nitro. Then work back up to the 1450 or H7, etc.

 

[brad nichols]

What about the pipe pressure fitting is it open as I have had them plug witn Loctite.

Brad

 

[John Seybold]

Thanks everyone,

Mark, the 1450 is pitched up, 3.75" of TE cup, 3.03 of COB pitch, diameter is 47.22mm

Motor is new, clearance is stock, which according to Glenn needs to be changed. I have a dial gauge that I bought many, many years ago that I need to learn how to use for the head clearance.

Pipe needs to be shorten, I think it's an S pipe. I bought it from the guy that was selling the Go motors.

I'm running 50% nitro.

Thanks again everyone

 

[steve wood]

Thanks everyone,

Mark, the 1450 is pitched up, 3.75" of TE cup, 3.03 of COB pitch, diameter is 47.22mm

Motor is new, clearance is stock, which according to Glenn needs to be changed. I have a dial gauge that I bought many, many years ago that I need to learn how to use for the head clearance.

Pipe needs to be shorten, I think it's an S pipe. I bought it from the guy that was selling the Go motors.

I'm running 50% nitro.

Thanks again everyone

get some blue plasigauge and set the head to .007,make sure the bottom of the button is not touching the case

 

[John Seybold]

Steve, how do you use that plasigauge? Hav you had any luck using the dial gauge that Speedmaster use to sell years ago?

 

[steve wood]

never used a speedmaster gauge.they won't work on a nova with the cone and dished piston anyway.

just cut off a piece of the plasigauge about the same diameter as the piston,so it will lay in the bore on top of the piston,then install the head and water jacket, then roll the piston over top dead center once. remove the button and measure the flattened gauge material with the scale on the wrapper.the material will be smashed against the head or the piston top,that doesn't matter

 

[shoboat]

John,

Propeller should be good number wise. I would like to see less cup 3.46"

and a shorter pipe length if possible. The head clearance will help a lot.

You Have A Lot Of Good Advice In This Thread,

Mark Sholund

 

[David Murany]

Pipe length and head clearance should get you close to 70 mph with that prop. We had the same setup and saw those results. You can use the speed master gauge if you zero out the button against the top of the piston. If it's a flat top piston just use a good flat surface to zero the gauge out.

Dave

 

[jayt]

The OP will love the JAE21 once he gets it dialed in. Mine is FE, but it tops out at over 76 mph giving 12 second laps with my driving, a real rush to drive. They are not pretty boats to look at, but are a blast to drive.

.

 

[John Seybold]

Guys, thanks a ton for all the advice/help. I was pretty bummed after I tried to get her going with no luck. Now I'm pretty confident with changing the clearance (just order some plastigage) and shortening the pipe, I think I'll be able to get there. Does anyone have an idea about the flow number? I know the number is not the same for everyone, but just a ballpark. Then when I get it dialed in, I'll re-flow the carb for my number.

John

 

[Elias Vazquez]

If you have a remote third channel needle, throw it in rich, make a couple laps to bring the motor to temp., gradually and slowly start closing the needle till it cleans out, and flow it. Done!..Always stay on the rich side of the needle!

 

[George Taylor]

John, I run the same boat with a Keep 21 from Glenn, he set the head clearance before he sent it to me, not sure exact numbers but the motor is stock. ABC H7 prop stock, 50% nitro. With the wrap around header, Glenn told me to set the pipe at 3 1/2 inches measured from glow plug to cone of the pipe. I've run a Mac high nitro pipe and running a c/f pipe now, both have done well. No problem with launch or running. I'm running between 60 and 70 with this set up. With the Keep 21 Glenn told me to be sure the engine was "loaded" ,enough prop, and give it some fuel. I have the pipe set at 3 1/4" now, running good. Hope this helps. Henry

 

[George Taylor]

John, also running the O'donnell 97t and 77t plugs, hot turbo. Try the Mccoy 59 in the 5 port. what part of the country do you live in??

 

[David Murany]

We run our 21s anywhere from 100 to 130 on the boris. Flow the water as well at about 100 on the boris. We use plastic t's for 1/8 inch line and tap them with a 4-40 screw and restrict the water with that. You can also use a needle valve but the t's are light and easy.

 

[Neil LaGarry]

We run our 21s anywhere from 100 to 130 on the boris. Flow the water as well at about 100 on the boris. We use plastic t's for 1/8 inch line and tap them with a 4-40 screw and restrict the water with that. You can also use a needle valve but the t's are light and easy.

Dave we have 3 Boris meters in our club all read differently on the same engine. None were matched.