Sputter and Die

[Watercadet]

I spent several hours at the lake yesterday and all I had were problems. Here is the setup: FF.12 with a Sirio .15 MACs 2.5 pipe, speedmaster hardware and Props 4 U V937/3. First run it was set up per instructions, and there was only cavitation. Brought it back and lowered the strut 1/8. Lauch and more cavitation, but it caught after 20 feet, accelerated, then bogged and and died. Raised the strut 1/16 and fattened up the needle. Same thing. Checked the plug and it was shiney and wet. Leaned it up (past the initial setting) and same thing. There was plenty of smoke on the beach and good throttle response. Changed props to a X442 and launch was no cavitation, but it was too deep and would not rev up. Brought it back in (still running this time) and raised the strut but the throttle servo pegged and radio problems ended my frusterating day. What gives. This motor would have way more power than the boat needs and it was rich enough on the beach, so I don't think it was leaning out on the water. Help...

Adam

 

[izitbrokeyet?]

Hi Adam,

Sounds like your boat is over-loaded with too much prop......I know the 442 was way too much prop for any .15

The v937 is a hard prop to get running if you have any resistance to begin with it will ventilate. You may want to try a 437 for starters with that boat....then move up to a higher pitched prop once the motor is run-in.

 

[ClayGlover]

Adam, try a Prather 215 or an Octura 1440 to get you started out. The x442 is typically a .21 mono prop, and it is probably to much for that .15 motor to turn, even on an outrigger.

On shore, the needle is pretty close if you gun the throttle and it hesitates a bit before wanting to rip. I'm guessing you know how to set the low end needle up?

I'm not sure about the cavitation problem, but get it running with one of the easier props first, then try the v937 later. BTW, are you giving it a good toss? I know shoboat's 937's are real thin and sharp, thus they run fast, but bend real easily. A tweaked prop can cavitate badly, so make sure it's not dinged or bent wrong.

What is the pipe's length from the center of the cylinder to the beginning of the widest part of the pipe when measured following along the centerline of the header?

 

[TomMoorehouse]

the v937 is a saw prop mostly and it can cavitate bad. the 442 is likely too big. try the 215 and have the strut about 3/16" below the rears. make sure the strut is flat on the setup table also.

 

[MikeP]

I ran a 1440, 215, v937 3, x438. All ran witout problems, some better than others. The x438 was the best.

I changed the stock carb on the Sirio to a nova rossi and it was much better.

 

[Watercadet]

Thanks Mike! I brought the pipe all the way to 8" and it would do the same thing even with the 215, so I switched to a X440 that was reduced to about 36.5mm and it screamed for about a minute then did the same thing. Now I was having throttle servo problems and that might have been the cause of the "bogging." I brought it back to the beach and let my wife run her tunnel. She was doing great for a while then she was headded back to the beach and got mixed up and came slidding (crashing) up on shore skewering my FF.12! All it did was knock off a rear sponson and not a scrach on the tunnel, so she... I mean I got lucky. Long and the short was I havn't run it since. Hey KB do you have a carby like Mikes got?? I might need to get one from ya. BTW the auction stuff is awesome and thanks for the extra care package!! What a bunch of stuff!

Adam

 

[MikeP]

I am running my MAC pipe at 8.5" I don't have radar but I was keeping up with the .21 monos.

Mike

 

[Will Gallagher]

Adam,

I would be happy to help you get this running after the District Races are over on Saturday or Sunday evening.

Regards,

Will

 

[Watercadet]

Cheers Will! Are you here in So Cal?

Adam

 

[Ron Olson]

How's the problem coming? My Fantom's have been giving me fits in the HH.12 so I took them out and put them in the Wild Thing .12 to get them half-way dialed in before putting them back into the 'rigger. Kevin's carbs were a great help in getting the motors running where they should and then some!

 

[waterbug]

 

Hey Ron

 

How's my Buddy doing........??

 

I have built a ff 12 from the free plans on site...

 

I need to know what size tubing to use for the flex cable and flex cable size...Please !!! .150x3/16 ???

 

Also are you running a teflon tube .......

 

 

 

Butch the Bug

 

[Will Gallagher]

Adam,

I live in San Diego.

I am sure with a few adjustments to your setup we will have you burning up the lake.

You have been receiving a lot of great information from this forum, but the one thing you have to keep in mind is the San Diego Pond is Salt Water and you're at sea level. I set my boats (Pipe / Prop) up very different when I run here.

Feel free to come early and we can have you ready to go when the water opens. Bring all of your props (especially the small ones)

See you this weekend.

Will

 

[Ron Olson]

Sorry for bustin' in guys. Butch, it's a wonder that I haven't throttled the little ............. :lol:

 

[waterbug]

 

Ron

 

How about a stuffing tube size ??

 

I'll come up and hold him and you cut that hinney.......... :lol:

 

[ClayGlover]

I ran a 1440, 215, v937 3, x438.  All ran witout problems, some better than others. The x438 was the best.

Hey Mike, interesting feedback on the x438, I wouldn't have tried that one. When you say it was the best, can you elaborate on what you liked about it over the others? just curious, before I pick one up to try. Thanks

 

[MikeP]

The x438 might be best for me because I am at high alt. It also gave me the best handling, was fast in the turns. The v937 was fast but sucked in the turns. The 215 was just slower all the way around.

These are my results for the first time out with this boat, just trying to give Adam the idea that any of these props should run and needs to check some other areas.

Mike

 

[Watercadet]

Thanks Ya'll!! Love you guys

Will sounds good! This weekend before the Labor day race? I can do.. I think.. that is early!!

Adam

 

[Ron Olson]

Now maybe you can whoop on that Nitro Hammer on that other site! :lol: :lol: :lol:

 

[Watercadet]

You know it!! I wish he was local so I actually could

Adam

 

[Will Gallagher]

Adam,

What I meant was, feel free to come during the race to get your boat ready for open water after the races are over.

Will