Riptide 12 Finally gets wet!

[Don Templeton]

Well Guys, I finally got a couple of days at the cabin to try her out. Set the needle and mixture on the TR to the book, started the engine and let my brother in law launch for me. (That's the last time he'll ever touch the boat! :lol: ) Anyway, I blew her out and launched her myself the next time. To say the very least, she's as close to perfect as I could ever have hoped for. Easy to launch, great in the turns, clean running with a long low rooster tail and very very fast. The only prop I used was from Andy. He called it a 1640- Cup 3.4".

However, I do have some problems with the engine. Most of my runs only lasted 4 to 5 laps before the engine would quit. The next day I made one run of about 3 laps and it quit again. After that I tried to launch it at least 6 times and it would guit about 25 feet out. I finally gave up. Time to look over the engine and see what happened. Sure hope it's not to bad! It did seem to be "sagging" before it guit. :huh: Could it be a poor break in?

Anyway, I love this little boat!

DON

 

[ClayGlover]

Well, I thought you framed that thing it's been so long!

Glad to hear you're having fun with it Don. I gotta get one of those props to try. It's been a year since I started building mine and I just finished it up today :lol:

 

[Eric Perez]

Don, look at the plug. It's the 1st indicator if the needle is set too lean.

Air-cooled small-blocks have a tendency to overheat after a few laps if you don't run then on the rich side of the needle.

Oh, quick question - Which of the spoons did you ended up going with?

Almost forgot, did having those candles on the front spoons mess with your CG? B)

You may want to post pics of your boat, I've slept some since the last time I saw your ride! Don't remember much except for the built in candle holders...

 

[ClayGlover]

Well, I don't know what nitro you're running, but I played around for just 1 tank today of 55%. The motors not broken in yet. I had to open the low speed needle all the way out, and had the high speed out about 6 turns for it to run on the rich side with the high nitro. I think it's your needle Don. The thing wouldn't even start at less than 5 turns out. I'm a little wary breaking it in with this level of nitro, but we'll see what happens, the coil is still shiny...

 

[shoboat]

Clay,

Did yours pull a V-937/3? What prop did you run? And how was the boat

running? 55% on an air-cooled motor?

Thanks,

Mark Sholund

 

[TomMoorehouse]

sounds too lean..... a great boater once told me..... "boats don't die from being too rich"

maybe a low speed needle adjustment? how is it on the shore? does it idle good?

 

[Don Templeton]

Plug looks pretty good. I was running 40% fuel, idles fine on shore. Mixture screw was even with housing, needle was out only 2 turns from bottom. Hmm, could that be the problem? :blink: I'd better check out the whole engine!

Eric, I think the candles were on the first 12 I built. Just wasn't happy with the way it turned out and started this one.

The sponsons I ran this time are the ones on the left. pretty much conventional with ride pads.

 

[Don Templeton]

Same as this but with rear sponsons 1/8" above wood strut.

 

[Don Templeton]

Wood Strut

I built it this way because that's the way we used to run Crapshooters before and even for some time after flex shafts. Obviously with the flex shaft I can get a much better angle. This one is at about 1 degree down.

 

[Don Templeton]

Rear with sponsons on:

I used an Octura strut barrel. There is only 1/32 ply under it. It's not movable so you better guess right. This time I did!

 

[MikeP]

NIce work Don, glad to here it all worked out.

Mike

 

[ClayGlover]

Clay,
Did yours pull a V-937/3? What prop did you run? And how was the boat

running? 55% on an air-cooled motor?

Thanks,

Mark Sholund

I went back out again. I only got in 3 tanks at the lake but the FF and nova 12 ran real well each time. 55% nitro and the V937. I had the usual few thing that didn't work like expected on a boats maiden day. The pipe coupler slipped loose on the last run, then my tx battery alarm started dinging, so that was it. <_< The 55% worked like a charm. Heat was not an issue, and the MC#9 looks like new.

I've got to make some adjustments because it had near zero left turn ability, although it turns right on a dime. Needed some left to track straight, and I've got the strut to deep. It was real fast though with your prop on there Mark! B) I haven't dialed in the needle and pipe at all, just breaking it in now.

Tom's firefighter is a winner. This is the first boat ever that I just threw in the water for it's first time out and it just hummed. And it was a heck of a lot faster than I expected for such a small engine! No fiddling around with the needle after initial setting by sound. I just fueled it up, started it, threw it, then held on.

Now back to Don's boat

Update- possible detonation due to the high nitro. It's hard to tell, but I may see some tiny pitting in the piston crown. I didn't break out a magnifying glass, that's how small they are if indeed they are pits. No big deal I guess. I may have to bring the head up a few thousandths to run at 55%, I'll check it after the next time out.

Update #2- no detonation, just imperfections in the piston. 55% is running just fine.

 

[Ron Olson]

Now you know why we're having such a blast with our .12 boats! Just think how fast we'd go if we had some motors and pipes made just for these Babies.

 

[shoboat]

Clay,

To get the boat to track straight,reduce the left sponson angle just a touch.

This will make the boat run straight. Just put a shim under the back rear

boom tube. Check your rudder length also,it may be a little short. The V-series

propellers really lift the back of the boat a lot,this can cause your problem too.

Thanks,

Mark Sholund

 

[ClayGlover]

Right on Mark. I may shim the strut too, but I'm going to raise the strut some and possibly lower the rears some I think. We'll see how dropping the front sponson works...

Workin the bugs out, right Don?

 

[Don Templeton]

Right on Clay!

I didn't have any trouble at all with the boat tracking straight. I think the only thing I did while building was turn in the right sponson maybe a 16th of an inch if that. I don't think a V937 will work on my boat. Too much lift!

You're right about the speed. I've only run .67 riggers in the past and I just couldn't believe how fast these little boats can be.

Sounds like you're doing really well with your boat. Do you have a picture?

 

[Preston_Hall]

Don,

I would recommend removing the low end needle completely. Then cut the spray bar back to the center of the carb opening. I removed the high end as well and used a remote needle. You have to provide fuel to make power. The extra fuel also helps keep the motor at operating temperatures. Everything seems to point to being lean. You shouldn't be having any heating problems. If you build another I would highly suggest an adjustable strut. This will broden your setup abilities and widen your prop selections.

Clay,

As suggested....................Reduce the angle of attack on the left sponson to help improve tracking. Then if needed toe in the sponsons. Put a long staright edge against the strut and make sure it is straight with the boat. Make sure the rudder has enough length as well.

 

[ClayGlover]

Clay,As suggested....................Reduce the angle of attack on the left sponson to help improve tracking. Then if needed toe in the sponsons. Put a long staright edge against the strut and make sure it is straight with the boat. Make sure the rudder has enough length as well.

Well, I goofed on the rudder I think. Should have left it long and ran it first instead of guestimating. The rear runs higher than I anticipated. Now I've got to improvise and move the bracket down to get it deep again. I ran it again today with a higher strut and it helped tracking at the expense of hopping and loss of turn speed :angry: I didn't have time to adjust the front left aoa. haha, I'll get these bugs out yet. I'm having fun with it.

Here's a pic Don-

 

[Don Templeton]

Nice boat Clay!

PRESTON:

I guess I don't understand what you're saying about the mixture controll. I'm using a rotory carb. Are you saying cut the spray bar off even with the side of the intake barrel opening. In effect, having no spray bar entering the opening at all like on a venturi?

Don

 

[ClayGlover]

Nice boat Clay!
PRESTON:

I guess I don't understand what you're saying about the mixture controll. I'm using a rotory carb. Are you saying cut the spray bar off even with the side of the intake barrel opening. In effect, having no spray bar entering the opening at all like on a venturi?

Don

Don, Preston is saying to remove the low range needle itself from the barrel, then cut back the needle itself, then screw the threaded needle body back in the hole of the barrel where it belongs.

He then says he did the same exact thing to his main high end needle, and used a third channel controlled remote needle valve as the main needle. It's connected inline between the tank and the now non-functional carb needle's nipple (non-functional because now the needle's tip has been cut off and the needle's threaded body is just screwed all the way back in to seal the hole it came out of).

He also recommends cutting back the fuel spraybar (the end of the little tube) in the carb barrel's throat so it's length is no more than half the diameter of the throat, aka "the center of the throat".

Apologies if you already knew this stuff, I didn't know exactly which part you didn't understand