Gas Deep Vee Questions

[gp70]

I have only limited knowledge of Gas RC Boats and had a guy ask me to finish setting up his boat. Someone else had worked on it but didn't get to far.

It's approx. 45 inches and is a Dumas hull and looks to be sevaral years old.

The bottom hole in the hull for the stuffing box, ( Correct term ? ) has been filled and a new one put at the bottom of the transom. He's got a G23 Marine engine for it and it has a 1/4 flexible driveshaft. It goes thru a brass tube. He had a very short tube at the transom but that didn't seem to be correct. Most of the flex shaft was exposed. I thought more was needed to support the shaft better. He had some extra brass tubing that I put a shallow curve in and now, only 2 inches of the flex shaft near the engine are exposed. I want to install it but want to be sure it's the way it should be

Is this correct, and is that all there is to the stuff. box, just the brass tube ?

I have read about a bushing for the stuffing box, is this needed on this type of setup. What type of lubricant or grease should be in the stuffing box and should it be sealed in some form?

Thanks

Duane

[Burkey1000]

Leave only enough flex showing to enable you to remove the collet. Normaly around 15mm. 2 inches is still too much gap. Thats all there is to the stuffing tube, so long as the bend you put in is nice and smooth. Make sure brass tube is linned up perfectly to the engine collet, the best way is to onsert the flex and attach it to the engine then tack it in place with a little glass before fitting fully. If its lined up correct you should be able to slid the flex right into the engine without having to move it. If its not linned up correcty it will snap. Use a wedge shaped piece of ply as a support inder the brass tube near the collect and glass it there to secure the tube. Use either glass of silicone on the transome end and your good to go. :)

[gp70]

Burk, thanks, it's looks like I'm on the right track, but need to fine tune the setup a bit more. I guess the next thing I need to know is how far out from the support brace to the end of the end of the brass tube near the engine is acceptable, I'm thinking I am going to have to remove the support brace and move it forward.

Positioning wise, the flex shaft goes right up the tube and into the engine pretty nice, no binding or hard spots, if the square on the shaft isn't perfectly aligned with the engine, all I do is rotate the shaft hear the transom and it slips right in where it should.

[Burkey1000]

So long as its held tight dont worry, i wouldnt go to the bother of moving it. Make sure the transome end is lined up with the drive also, its gotta be inline otherwise the flex will snap at the drive end. Just take ya time and make sure all is nice and straight and you wont have any trouble. A pic of the drive frome the transom end would help to see if all is ok. Any questions just ask. :)

[gp70]

a pic from the rear

[gp70]

another one

[gp70]

Thanks again Burk for the info,,, and I do have a few more questions,,,,

1. How much of the brass tube should be hanging out the transom ?

2. Angle of the fuel tank ?

3. Tank pickup location, towards the front or rear of the hull ?

4. Water pickup tube location on the drive assembly ?

[Burkey1000]

Only prob i see for the tube is it looks like its comming out the transom at a downward angle slightly, might be pic but better if its straight out to the drive otherwise it will stress the flex and will limit your movement of the drive upwards. Put a ruler under the keel of the boat, look at the gap between the ruler and the drive and set the angle of the drive so the gap between the ruler and the drive is the same throughtout its lenth, then aim at getting stuffing tube straight out the transom and inline with the ferrel, the gap looks ok.

Angle of fuel tank not sure what ya mean by that. just fit it in the boat even and make sure the pickup inside is right to the bottom. Try and get the fuel tank as close to the centre of ballance as possible, not sure what tank your using. You could always use an IV bag but if its for fun might not be worth the hassle of changing it.

Water pickup, depends how deep the hull runs but on first running of the boat make sure your getting water through the boat, run it slowley past you so you can see the water outlet and check for a good flow.If not drop it down a little. A little testing will find the sweet spot, just dont drop it to low so it causes drag. Better a little low than no water comming through. A good tip is before you connect the water pipe on the back just blow through the tube and check all is clear then get her wet.

DONT run your driveshaft the way you have it, you need a gap between the thrust washer infront of the drive dog and the drive otherwise you will destroy the bearings and the drive. A gap of atleast 4/5mm. :)

[Burkey1000]

This is where there needs to the gap of around 4/5mm. Think the pic makes it more clear :)

[Burkey1000]

Height to centre of stuffing tube around 12 mm, Adjust strut to centre of drive is level with centre of stuffing tube, the level the drive to a neutral position as in the diagram below. Sorry the drawing crap :D

[Burkey1000]

The blue line shows what i mean by Putting a ruler under the keel and setting the gap even this will start the drive out in a neutral position, a good starting point. You may know this already but incase you dont the info is there for ya. :)

[gp70]

I did notice that the stuff. tube exiting the hull was not as lined up as perfect as I would like it to be and I plan on correcting that.

As far as the tank thing, I was wondering if it should be level, not not angled up or down for fuel pickup. And the actual location of the klunk pickup I was wondering about also. With planes it simply goes to the back of the tank, but with the tank being the other way, I wondered if the pickup should be setup so it's closer to the front ( actually rear, where the stopper and lines exit the tank ). A buddy said to run the brass tube into the tank and then bend it 180 degrees, then attach the rubber line and then the klunk, so the klunk stays closer to the engine and is actually right near the stopper. (See attached pic)

Would it be ok to use a dremel tool and open the water pickup up a bit, just removing a little of the inner brass to bell shape it slightly, to aid in water flow. It seems small. What I had in mind wouldn't change the outward appearance at all, just increase the size slightly of the inner part of the hole rigfht at the curve.

Good info on the gap between the bearing and the drive dog, never would have thought of that.

Would a brass line mounted in the boat along the stringer perhaps, be ok for the water line coming from the water pickup. I was going to epoxy a short piece of brass tubing thru the hull to attatch the rubber line from the water pickup, but was thinking about a brass line thru the boat.

[gp70]

Moved the tube a little higer up the transome and corrected the angle of the stuuf. box exiting the transom. A little up at the transom and down near the engine and it looks pretty good to me now.

[gp70]

From the rear

[gp70]

Here's my attempt to salvage the radio box, the guy didn't have a clue. He butchered up the servo mounting plates by cutting them to short and glueing the reinforcement bracket in incorrectly. I substituted the abs for a peice of 5 ply plywood, it was actually stiffer then the abs.

[gp70]

You can see where the switch was mounted and where it is now.

[Burkey1000]

Its looking good, before you fix the stuff tube make sure its around 10/12 mm to the centre of the tube, may just be the pick but it looks a little high, its to the centre of the stuff tube not the bottom of the stuff tube, like i say it may just be the pick. But its looking good so far. As for the fuel tank bend the pickup tube 90 degrees and then just use enough tube on the end of it to get the clunk to sit at the bottom of the tank. Depends on the carb your using, but dont forget the tank needs a breather pipe in it, and if your carb has a primer bulb on it, it will need a return also. A good way to make the vent is use an old plastic 35mm camera film pot, drill lots of little holes in it and then fill it with a piece of sponge. Get hold of a water nipple and fix that in the lid of the film can and then connect a pice of fuel line from the nipple to the air pipe on the fuel tank. Make some sort of bracket to hold the film can under the top of the hull, or wait till you put your floatation foam in and just insert in the side of it. Try to keep the weight down as much as possible so use some thought in the building etc. Just mount the tank in the centre of the hull, you can make a little wooden tray for it and resin that in and then hold the tank in place with rubber bands on small hooks in the tray. Dont forget that all wood placed in the boat should be coated with a thin coat of resin to stop any water rot. Looks like your taking your time and getting it right, well done. any probs just ask. :)

[gp70]

Well, I epoxied the tube in place last night and went over and remeasured it tonight after reading your latest post. I'm am slightly off, it's 13 mm, from the bottom of the hull to the center of the tube, he's going to have to live with that. It must have moved slightly when I flipped it over and added some epoxy on the inside near the transom.

More good info on the breather can, got all the parts for that except the water nipple. Something else I hadn't thought of.

All the wood WILL be resined after the setup is complete and it's torn down before the final re-assembly

Here's the next set of questions....

1. 3 tubes in the tank, ( fuel feed, exhaust pressure and breather can ), or just 2, ( fuel feed and breather can ) ? Is adding a 3rd line for exhaust pressure recomended ?

2. Can I hold the tank in place with Velcro ? It might diffficult to drill 2 holes for the hooks. Pretty far into the hull.

3. It was mentioned that some guys use a 2 litre pop bottle shoved up into the nose of the boat for a floatation device. It, to me, would be the lightest choice of a floatation device.

4. The engine does have a primer bulb on it, and the tank only has 3 available outlets, where would the return line be connected to if I was to use all three? This si assuming I add exhaust pressure.

5. Best method of sweat soldering the coulper at the end of the flex shaft ?

Thanks again Burk, your help and suggestions have truly been invaluable !!! I'd be lost without your help !!

Duane

[Burkey1000]

1. OK the engine is a g23 so i assume its a gasoline boat and not a nitro, so therfore you do not put an exhaust pressure in there at all, you have feed, fuel return, and breather, thats your three, do not use ex pressure at all.

2. When i say use hooks you would normaly build the fuel tank holder first and then resin in place. I dont think the velcro would hold well. And once a little fuel gets in there i dont think it would last long. Is there a tank holder already in the boat or nothing at all. If there is not just build a flat tray with low sides, place hooks on sides and hold tank it that way. It must be secure any less will just not work and if it moves around alot you have the chance of fuel leaking and a fire too.

3.The best floatation is pool noodles from wally world, a pop bottle is not enough i wouldnt think, i know i would never use one or risk it. Fold the pool noodle in half and insert it in an empty hull it needs to go from bow to transom on both sides, cut away any places that might get near or reach exh manifold and carb etc.

4.Question 4 the answer is in reply 1

5.OK out of everything your going to do to build the boat, soldering the flex to the brass ferrol is the one thing most people have trouble with. Use normal plumbers solder and flux. Everything must be clean and i mean clean. Use a disk on a dremmel or something that will clean the outside to bright metal then clean with fuel or something to make sure its realy clean and dry, the same goes for the brass ferrol. Once all is clean smear flux on flex and i normaly put a little in the ferrol. heat the ferrol up and use just enough heat to tin the inside of the ferrol with solder, Do not use more heat than needed to get it to flow, that is the biggest mistake people make. Once the ferrol is tinned do the same with the flex, again use only enough heat as needed and no more, then heat both parts and join the two together with a little more solder and leave to cool, do not drop in water to cool let it cool down at its own pace. If you heat the flex and it turns black its either dirty or your using to much heat and it will not take very well. If youve never done it before and you get it right first time your doing well. Just a word of warning, first time out with the boat if the engine revs but will not move its prob the flex joint that has given way, always take a rescue craft with you so you can recover the boat safely, do not try and swim for it. Not sure what type of fitting you have on the engine side, if it is a square insert your ok, but if its a round collor that you tighten to lock the flex in, then you need to solder that end too. I used to use silver solder on that end with a acid flux, But you could just use plumbers solder for it too. The purpose of sealing the other end is when you clamp the flex in it, thay can start to unwind a little which will cause the flex to spin on itslef because of the way they are made, sort of a wrap on a wrap, this will stop that, just solder and rub down till slides back in the round collet. Good luck with it all. Any more Qs just ask. :)

[gp70]

Burky, Thanks again for all the help you've given me on trying to get this project as close to correct as possible.

Getting close to the final push and have a few more questions I need info on.

There are several inlets on the carb and can't seem to find any info on what goes where. Any help in this area would greatly appreciated. I also have an inlet on the spacer between the carb and the engine, I'm assuming that this is in the correct position, and it appears to be for a water line. Just not sure what to attach to it and what the port actually does

[gp70]

Third inlet.

[gp70]

I think I have the straight pull conversion figured out but never could find any info except for a pic of a boat with the carb in this position. Does this look correct ?

[gp70]

The linkage is a straight shot from the radio box to the carb, so I think I have it correct.

[gp70]

Added supports for the quick release connectors for the hatch.

[Burkey1000]

do you know what model carb that is, never had one with 3 on before, infact dont know of any with 3, if ya have a carb number, should be stamped on the carb, 644,488 etc. The one on the spacer is a for a water pump, you dont have a clutch, so you dont use a water pump, so remove the alloy carb spacer. Never used a throttle like that before its not the norm, plus when you remove that alloy spacer the carb will rotate round further moving the primer bulb in a more upright position. Need more info on the carb to be sure, will try and find some pics for ya.

[gp70]

It didn't clic till a buddy said vacume, and I then realized it was probably for the water pump that I had previously decided not to use. The primer bulb was in the upright position but that put the carb linkage behind the carb. But that spacer seemed perfect for the straight pull conversion ( that is said to be supplied to me ) so I thought it was correct. I did see a pic of a boat that had the carb in that position and that also made me think I was doing ok. Oh well, 3 steps forward and 1 back, seems that has been the SOP with this boat :confused:

Here's a shot of the carb, it has 2 numbers on it and you couldn't make them out very well so I took care of that.

[gp70]

Here's the pic that made me think I might be on the right track.

[Burkey1000]

if your not using the pump you cant use the spacer therefore the carb will rotate round anyway making the throttle system no good anyway, also with the spacer removed will help performance a little the last thing ya wanna do is lenthen the intake. have you seen any pics of throttle links etc for the carb the other way around. the carb is a wa 167. The reason is that engine is a weed wacker not a zen, is the model of your engine a 230pum or is it a 260 etc.

[gp70]

It's a G230PUM.

[Burkey1000]

the black one on the top next to the primer bulb is the fuel return, that im sure of. The black one near the bottom on the side, i would say is the feed in, as for the other i havnt got a clue. never used a 167 before but looked at the walbro site and couldnt make out much but never had a carb with 3 before. Will try and find out.

[gp70]

I do have another plate for the bottom of the carb and it could be used in place of the one that is on the carb now, eliminating that third fitting.

[gp70]

And while looking for exploded veiws of the carb, I found this that told me that 2 gaskets weren't even installed in the carb. It was obvious that the carb had been apart, ( lot's of bugered screw heads ) and found the one of the gaskets in one of the bags that had extra crab parts but the other one is MIA. I find it harder and harder to believe that an adult played with this thing, looks more like the work of a 10 year old. :confused:

[Burkey1000]

Well i would use the other plate then, think the 3rd one was abit weird. IF you havnt got all the gaskets you will have to get them. Might be better to get a new carb, you can normaly get a stock 644 on jims for about $15.

[Burkey1000]

So hows the build going.

[gp70]

Well I got working on my vintage van ( gp70 stands for gray primered 70 ) for the last 2 weeks and haven't sat down and made any progress in that time, other then getting the clearcoat and hardener from my boss, but I plan to finish it by the end of July. Just need to make a little more headway on my van and then get the boat finished up
.
Saw a big bore carb on ebay but the bid went to high, so the carb situation hasn't been fully addressed yet. Not to much more to do mechanically and will probably start the tear down for paint. Got the tank mounted ok, and still have to finish the breather can. And not 100% happy with the solder job and while it's getting painted, I plan to take the ferrel back off and solder it again.

The guys father passed away 2 weeks ago and since his father bought this boat 20 years ago, I started wondering if he might want something on the boat dedicated to his father. When he stopped by the other day, I mentioned it and was pretty suprised that I was thinking the same thing he was. His father had 2 boats in the past named "Moondoggie" and we decided to add that to the transom. He also gave me a small pic of an offshore that he liked the color scheme on and asked if I could do that. I told him sure, no problem and he then told me he'd give me $200 plus materials to paint, pretty good incentive I think. He's in no rush for the boat but getting it done by the end of July shouldn't be a problem.

Thanks for asking Burky, I seriously can't thank you enough for guiding me thru this, I would have been lost without your continious help.

Duane

[Burkey1000]

No problem glad i could help :)

[gp70]

Got started on the paint work this week.

[gp70]

pic 2

[gp70]

pic 3

[gp70]

pic 4

Going to add some orange and purple graphics to the yellow area this week also.

Duane

[Blackmanba]

Beautiful colour scheme :)

[gp70]

My boss's Offshore hit the water for the first time in 4 years today.

Duane

[Burkey1000]

Realy good job ya doing there keep the pics comming as you progress. :)

[tom1]

the nipple on the bottom of the carb joins to the carb spacer where a water pump would go

it is done on quik draw engines to pull more fuel to the engine and it helps if your carb has airleaks

[tom1]

http://p086.ezboard.com/fjimsrcboatdockfrm2.showMessage?topicID=5582.topic

that link will tell you what it is for

[redbull91rscmb]

hi ,i have been looking at your info for the carb fuel system for mr. gp70. the bottom one under the carb is for the diafram to draw fuel to the carb from the crankcase presure and like you said its not needed if the carb block and cylinder has a hole that matches up with one on the carb face. as for the one on the ali plate this maybe to replace the hole thats in the face of the carb as it maybe blocked off from the plate.
put a finger over the front of the carb then pull the cord and see if any air sucks in / out from the one on the ali plate if so then this one links to the bottom one so the fuel can be pulled from the tank.