first run, nowhere near successful

[camaroboy383]

got to pull the new rigger build out yesterday and slap it in the water... had nothin but issues.. thing would run mint on land,,toss it in the water it will go anywhere from 10 ft to 100 ft and stall.. you could phisically see the thing slowing down till it died..after several changes to the hull and props and the same issue,,i noticed the spray from the boat going through the water was drowning the engine out..also filling the tub in the engine bay,further it went the more it filled...never seemed to actually get on plane though so i figure thats why it fills so much.... is this a common issue in a wide open small rigger???? its a ff .12 with widened and lengthened tub for a .18...for sure its water killing it,as its a real bear to start after pulled from the water.. so what should i do????? a 90 degree fitting on the mouth of the carb??? or increase front sponson angle??? im lost??? this rigger stuff is all new to me.. i dont have a cowl yet as i didnt want to get into buying a tank from walt and building or buying a cowl for somthing that i might not like...

any help appriciated

alden

 

[Mark Leyde]

We need more info like Motor make, what has been done to it, pipe used, props etc.

 

[gooycheese]

Hi Alden,

Some good pics of all angles would be nice also. Like pics of how deep the strut is in relation to the rear sponsons? How deep the front sponsons are in relation to the tub? How heavy is the boat dry? And like hydroracer said engine, pipe and prop make a big difference. Ohhh it does sound to me just based on what you have said you could be trying to run to lean, if the boat runs great on shore and dies soon after launch you are most likely too lean. Or you may have to big of a prop, go with the smallest prop you got first. I can run anything from a x637 to a 1440 to a v937, I would say try a prather 215 or a x437 ..........go small first and step up with success.

Good Luck,

Paul

 

[camaroboy383]

ya i didnt even post the important stuff..lol.. hpi .18 buggy engine,,cut down head,,to keep some heat in the engine.. ab 21 ss pipe at 8" to start with..tried 215,438,440,637,1640,detounged 637,,all these had the same results.. some would take off faster than others,but regardless the same outcome..aquacraft miss vegas strut,rc worldwide (dont actually know the name)break away .21 rudder, miss vegas turn fin,and vegas flex and stuffing tube w/liner... now i did check my srut a little while ago and it was center line of shaft with bottom of sponsons,, but i was reading in the other thread to set it even with the sponson bottoms,, so i have made that change..sponson angles,,,hmmmmmm dont have a angle finder but i set them per the ff instructions with templates of the sponson / tub orientation,,till i can grab one.. for sure not lean,,, i opened that needle up after the first two failed attempts to the point where it would barely run on land and yielded the same results,,but would obviously leave much slower... turn fin is set up square to the ride surface also...tub was widened 1/2" and lengthened 1",,sponsons are per instructions..

now like i said,,,im pretty confident that the water splash is drowning it..engine is pretty high in the tub so the side exhaust can actually clear the tub..air cooled head fins end right at the opening of the carb... the head is some what deep,, with slices going all the way to the center between the fins..im suspecting this is basicaly funneling water into the mouth of the carb with the boat moving foward,,as the water would want to exit the rear slits in the head directly over the carb..when i bring it back,,like i said the engine is a bear to start, having to pull the plug cause its basicaly hydro locked,, having to cycle fresh fuel through a oil out tool to get it to fire.. just curious if this spray is messin with anyone elses setups..

on another note,, what do i do about the tub filling???? auto bailer in the most rear side of the engine well???

alden

 

[Mark Leyde]

First off do not get discouraged. The .12-.21's are a bit touchy to set up. They have a hard time launching. But when things are set up right they launch easy.

What % of nitro are you using?

 

[camaroboy383]

First off do not get discouraged. The .12-.21's are a bit touchy to set up. They have a hard time launching. But when things are set up right they launch easy.
What % of nitro are you using?

ya i was told they are fineky,,im not discouraged,,cause any hull takes time to set up.. just looking for ideas pointers.. i run 60% odonnel, but will soon be switching to 50% as thats what i have..

 

[Rick Sowell]

Alden: like others have said, it sounds like you might be running too much prop to get it on plane quickly, are you giving it a good flat launch, these things are hard to launch if you don't get a good toss, if they plop down in to the water from the toss they lose all forward speed and the prop bite kills the motor speed and they slowly come to a stop and plow the water doing it, filling the tub.getting the right toss is the most important and using a small prop to get through the first stages of tuning is the most important, try the 215 or the 637, I had the same problems with the 40mm props until I went smaller and figured out how to launch these things, also you can't launch these by your self, tried that don't work, get some one that you can trust to give it a fast throw and see what happpens, be on the throttle and let it rip. good luck, they are a blast to run and cheap on fuel too.

 

[Buckshot]

Do you have a drain hole in the bottom of the tub in the fuel tank and engine compartment?

-Buck-

 

[camaroboy383]

Rick the 215 and 637 yielded the same results. She sure is gettin a good flat toss with lots of momentum. Im use to the high speed toss with the modded tunnel i run.

Buckshot, no i have no drain in the engine compartment, thats why i was asking if i should install a bailer in the most rear far side of the tub, far side being the left..

Alden

 

[TomMoorehouse]

Do you have a drain hole in the bottom of the tub in the fuel tank and engine compartment?
-Buck-

thats's what i was thinking.....

If you modified the tub then I have no idea how it will launch. built to plans they are easy to launch. my guess is it's a fuel system problem.

 

[Grimracer]

If it runs FANTASTIC on shore.. it aint going to run well on the water.. Turn the low speed needle out.

90% of the time if it quits its lean.. this might mean tank, needles, bearing, air holes or what not but you get it.

Keep us posted.

grim

 

[camaroboy383]

Thanks for the suggestions. I dont want to get ahead of my self here. I made the strut change, so i will see what happens with that.will mess with the needles at the lake. Also grabbed a nice 90 degree vaccum fitting that fits sweet on the od of the carb neck,also will try that if i have too. Will keep you guys posted.

Still though is the bailer worth while?? Or will my tub filling issues resolve itself once the boat is dialed in.basicaly what im tryin to say is,, does even a perfect running rigger get gobbs of water in the tub?? With out a cowl that is..

Alden

 

[Mark Leyde]

Still though is the bailer worth while?? Or will my tub filling issues resolve itself once the boat is dialed in.basicaly what im tryin to say is,, does even a perfect running rigger get gobbs of water in the tub?? With out a cowl that is..

Alden

No it will not until it stops then it will fill up.

I would check the head Clarence and take it down to about .008" before you head out next time. Most buggy motors have more Clarence than that from the factory.

 

[camaroboy383]

Still though is the bailer worth while?? Or will my tub filling issues resolve itself once the boat is dialed in.basicaly what im tryin to say is,, does even a perfect running rigger get gobbs of water in the tub?? With out a cowl that is..

Alden

No it will not until it stops then it will fill up.

I would check the head Clarence and take it down to about .008" before you head out next time. Most buggy motors have more Clarence than that from the factory.

Mark i think you might be on to somthin there.. Checked the clearence and it was .028 ,, so the engine is strange the sleeve is actually way down in the crank case.like .050 recessed. So i didnt see the shims hiding on top of the sleeve. 3 shims total .008 each. I can go all the way down to 4 thou. So do you still suggest 8 thou??? Or maybe run like .006 ???

Alden

 

[socco72]

check your tank and make sure it has no air leaks my outboard hydro did the same thing last weekend throw it in and it would go for a second and die and never get on plane.

 

[Roxyflash]

Cut down head?I seen this before not sure how it was cut but does it have a great seal?If it dont seal a 100% it wont launch.

 

[Brad Christy]

Alden,

That head clearance is probably the sole culprit. Most good .90's only have about .015" or so head clearance. .028" is off the charts! :blink: I run .006" in my MAC21, so it would probably be good for an .18, too.

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

 

[camaroboy383]

Socco i actually just checked all the lines and the tank, and made a revision, dumped the clunk and just bent the tubing to go where i needed it.. While on the fuel subject, i noticed the engine vibration agitates the fuel like crazy. Normal? Or should i slap some thin foam under it. I used a 4 oz. Flexy tank and it is wedged inbetween the sponson tubes. No silicone just wedged,kinda forms around the tube.

Roxy, the air cooled head is seperate from the button on this engine. Button is bone stock.i cut like 4 of the top fins off the head to hold some heat in the engine.

Brad, i along with many others will agree with you on that bein off the charts... Although the aqua .18's run a rather large head space also. If i remember correct it was right up there around .025-.028 wonder why?? Low low nitro in mind??

I checked the engine for air leaks, i ended up setting the head space at 8 thou. As i had a 4 thou shim,seemed like the magic number..lol..increased the aoa of the fronts a tad. Hopefully it will run for me now. Fingers crossed.

Alden

 

[Mark Leyde]

Mark i think you might be on to somthin there.. Checked the clearence and it was .028 ,, so the engine is strange the sleeve is actually way down in the crank case.like .050 recessed. So i didnt see the shims hiding on top of the sleeve. 3 shims total .008 each. I can go all the way down to 4 thou. So do you still suggest 8 thou??? Or maybe run like .006 ???

Alden

.006 will work fine. .028 was way to much for a boat motor. Use your 215 prop untill you have it set up good. then make prop changes. I think you will have a good run the next time you go out.

Good luck.

 

[toyotatruckin]

You may even need to try a smaller prop than a 215 I lost all my pictures due to a computer crash so I used my electric rigger from photobucket and paint shopped you drain hole placement front one should be at the rear of the front compartment and second one should be at the rear of engine compartment easy way to say it is follow picture and add a hole in every compartment except the radio compartment keep working at it youll get it figured out