On my stock RCMK with the 929 carb, what should the needles be set at?
Can a diaphram for the 257 carb be used on the 929 or are they different?
I fire her up and she goes about 6 or so feet and then quits.
Any suggestions would be appreciated.
Thanks
Tar

929's @ 1 1/4H and @ 1 1/2-1 3/4 L

RCMK' are revers so DON'T over prop it. Run a smaller prop until you get mixture close and some break in time on engine, then prop up.
* Also gap S/P to @ .015"

Thanks for the setting for the 929 Scott.

Now since it was only going about 6 or so feet and then quitting, I thought about changing the diaphram. Will a diaphram for the 257 fit the above carb? The motor has been run before.
I was going to try the 2716/3 first but would a 472 be better until I get the needles and pipe length right? Or what prop would you suggest. I do not have many but some.
The motor is in a Conquest with a 2 inch band pipe.

Yes diaphragms are the same across the entire WT carb series.
2716/3 sounds like TOO MUCH PROP ... a 2716/2 is tough to get running right until quite shallow having strut near 3/8 to 1/2: above ride pads. Even then some motors still won't pull them

found Conquests in general will want strut 1/4 to 3/8 above pads anyways.
BEST prop I ever used on my Conquest was the 7016/2 with some minor mods.
Also try 6717/3 or 6518's

** What props DO YOU have ?

I agree. Change the prop and set as said. I run mine at like 5/8" above bottom of sponsons! Running 6717/3 Daily props.. in the 410 to -425 range depending on conditions. I wouldn't waste too much time with a 472 on this boat. If you don't have props mentionned, and do have sometine like a x470 or x670 try those to get going.

I'm assuming you went through all the regular checks of fuel, fuel line, filter, etc??? make sure no water is getting to carb...

Hey Tar you going to get that thing wet at our pond someday?
would be nice to have you at the pond we have a big race comming up
in Spet... our IMPBA sanctioned event OHH YA.

well I see your in good hands with Scott and Marc they know what there doing
4 sure.

have a good one
Luc
OVR Admin

Scott and Marc:
Marc all the fuel lines, filters etc are all new to go along with the boat. The only thing that is not new is the RCMK with maybe if that, 1/2 hour on it. Since I had run the RCMK a bit before I thought of changing the diaphram to see if that would work. I had the L at about 2 1/8 but have since changed that once I found out the approx. numbers for the needles. It starts fine and idles great but when I throw it in, she goes about 6 to 8 feet and just dies. Have not tried the new needles settings in the water yet.

The props that I have are: 470/2, 470/3, 670, 472, and a 275. Oh I do have a couple of the 2716 in a 2 blade and a 3 blade.

I hope to get to see you folks at the pond some time during this month or for the big race in Sept Luc.

Thanks for all of the help folks

Tar

Put the 470/3 on there for now. Set strut about 1/2" above sponsons. That's all non critical for now. Get it running and tune later. Make sure the pipe is at a good known setting, maybe even a tad long. We just want to rule out the engine being overloaded. Set carb as per Scott's recommendations.

Important question here: has the motor EVER run fine in this boat since built? If so track back what you changed since. If it has never run in this boat, start from the beginning. Check everything by process of elimination. Start by making sure the carb is assembled correctly if you've taken it apart. While you are there if you don't find anything abnormal, consider changing the diaphragm and the check valve membrane ( the rubber flappers on opposite side of carb). I've seen these curl up or stick causing issues. Also check the filter screen in carb. Then move on to the fuel system. Make sure all lines are on correctly and not leaking or taking in air. Check the pickup in tank or bag make sure nothing can be restricting it and that it's getting fuel like it should. Also take a good close look at the carb iso block. Make sure it's flat and nor taking air. Sometimes running richer settings can help confirm if you have an air leak if it's not too bad. If you have to run real rich to get it going start looking for air leaks. There really isn't much to these gas engines and if you go one step at a time and eliminate possibilities you quickly find the issue. All these checks will lead you to the solution or in the end confirm an engine problem, in which case then you do the same kind of elimination proces, this time on engine components.

Good luck. Keep us posted.

Marc:
Thanks for all the tips and info. The answer is no. This is the first time that motor has been in the boat. Just finished building the new Conquest. I was trying to run it for the first time in the water. I had fired it on land with water through it to see if all was OK and it seemed great. The ISO block is one of CC's. So all should be fine with that right? I will double check all of what you suggested Marc.
This sure is a great way to start when one just built a new boat.
Thanks again for all the tips and I will keep you informed.

Tar

Well shouldn't be too hard to find the problem. If the motor ran fine before, it's probably either a fuel issue in the new setup, or parts in the carb that went bad in storage because of fuel left in them (ie the diaphragm and or pump). The ethanol in today's gas is terrible on the carb internals when stored with gas in them. I would start with a kit in the carb and take it from there. Make sure you put everything back in correctly.