Thompy

^Bump^

ob nut

My Feedback: (1)

Never seen a carbon prop being used, at least on nitro tunnels. Sounds like you are on the right track. Remove material from the prop hub. Remember to rebalance the prop when done removing material.

Thompy

I saw on internation waters that the kb's have a big time prob with this, and I read up. I cut the water pickup tube down also to just under the cavitation plate. Seeing is how this is just for fun and not racing I don't have to worry about breaking any speed modification rules. It's helped alot, still kinda in the way so I still need to do some filing on the tube, a little here and there and it should be ok. What do you guys use to file these props? Of course the stainless, aluminum, or brass props. I suppose I'mma have to dig into this stuff to get it right and have myself a good prop. I'm more of a do it yourself kinda guy anyway and I'll just go with sharpening and balancing them myself.

ob nut

My Feedback: (1)

Check out the [link=http://www.rcuniverse.com/forum/m_3120686/tm.htm]Prop Thread[/link] here on RCU. I haven't looked it over myself so can't say if it covers carbon props. I did have an Irwin lower unit, which is made from special material used on the space shuttles. As Jim stated, use a razor blade to trim / sharpen out his lower. Don't know if this process would work on that prop you have. In my 20 +/- years of running K&B 3.5 OB, I've never had the prop hitting the water pickup tube. I've never used one of those props though.

Thompy

I was reading at Internation and JD was saying how he was talking to someone at K&B. He was holding a new SX and it had a X-440 on it hitting the water tube. The guy from K&B wanted to aruge that it won't hit while he was spinning the prop into the tube. lol..... I got it to work last night. Just filed down the tube, it will still pick up water mind you, just not so far down off the caviatation plate. The hub on that prop was just to big. I filed all I could off of it, till I was basicly at the blades. Oh well, its just a waiting game now

On a lighter note. ob nut, is the CMBC getting ready to start sanctioning races again? I would love to take a trip and see what this is all about. When does your guys' season usually start, and how long does it last? Just a little curiosity.

Thanks as always!

ob nut

My Feedback: (1)

May have missed that thread on IW.

[link=http://www.cincymbc.com/]CMBC[/link] site has been updated with the IMPBA santion race - July 8th & 9th. Club races haven't been anounced. As a club member, pond is open any day of the week. Watch the site for updates..

On a personal note, I'm waiting for the key to the locks. After that, I'll be up to break in a new Mac.

Thompy

luckyyyyyyyyy..... I've got to many hobbies.... lol... I get myself into alot of stuff; boats, cars, 4x4's, hunting, fishing... this one looks like something I can stick around in though for a long time. Nothing like football or something like that. I have highschool friends who are playing college ball and already either getting hurt, or getting the crap beat outta them. They'll think twice when they are 25 and have had a torn ACL or MCL and I'm still playing around with my toys.

Thompy

Well I got all my stuff from tower hobbies in, and put it all together. Fuel tanks, throttle cable, fuel line/filter. I'll try to get some pics up soon if I can figure it all out. I'm sure I can. I tried starting it today just to get it started and had no luck. I believe it was flooded due to the WD40 that I pumped in the carb when I stored it for a few weeks, and due to pumping to much fuel in the carb throat to try to get it started. Never the less it should be running soon. It got cold all of the sudden round these parts but as soon as it warms up I'mma try to get out and run her. Imma paint this boat as it needs a fresh coat of paint, but seeing is how it has already been painted I need some advice on what to do. Should I strip the boat to the bare wood? And as for you guys do you use just basic hobby spray paint primer, then a basic hobby spray paint, then shoot it with some kind of sealant clear coat? Or on the other hand, can I use automobile spray paint primer/paint, and an auto clear coat spray?

ob nut

My Feedback: (1)

Everyone has their choices on what to use for painting. Most hobby supply paints will hold up to low nitro. If you plan on running high nitro, my suggestion is for a good automotive paint. I use PPG paints only with 2021 clearcoat. It holds up to 65% nitro without problems.

Thompy

Are you shooting this out of a spray can, or though a compressed air spray gun?

ob nut

My Feedback: (1)

5hp air compressor with a HVLP touchup gun.

Thompy

ahhhh I see. I don't have access to an air compressor, SO, I'mma have to go with some type of can spray. I'll find something, and its better than what it has on it now. lol... thanks for the help

Thompy

Well I tried to fire it up again today in hopes of at least being able to make a few laps to get it set up, nothing major. I wanted to make sure it was going to fire at home before I made a trip to the local lake with my V-Bottom retrieval boat. I put a drill on the cone nut, made sure it was spinning clockwise at the cone, and held my finger over the intake to prime it. What I got was the fuel coming ever so slowly to the carb, and once there it would just spray out of the throat, not sucked into the crankcase. I'm sure something is backwards, or is the normal? I tried for about 15 mins in hopes of getting something, but all I got was little "hits" out of it, no starts. Finally I turned the starter cone by hand, and it would fire a little, and push the cone in the other direction, like something was backwards. Mind you EVERYTHING fuel wise is brand new. Tanks, line, filters... and is all set up per the manual and your guys' directions. Any suggestions?

ob nut

My Feedback: (1)

Well, let see here. Pressure line hooked up to the motor? Pressure and carb line on the correct tube coming out of the tank? Take both lines off the motor, leave them hooked up to the tank. Now blow in the pressure line. Fuel should start coming out the carb line. If this works, lines are correctly setup. Needle open to 3 1/2 turns out? Carb open around 1/16" ?? Nothing much to be "backwards" within a K&B OB motor. Only thought would be is the sleeve in the correct position? Where is the tank in relation to the carb? Raise the tank up as high as possible under the cowling. A hopper tank might need to be added. Put a few drops of fuel directly in the carb opening and try to fire it up. If not, let us know....

Thompy

Well, I've tried putting a few drops of fuel in the carb. And its fired up before, only one time I might add. I believe the other times I have done this is because I put to much in and flooded it. I did read about the barrel being open about a 16th of an inch at idle. I think this could be my problem. I broke the motor down, and put it back together again and it all checked out ok. But when I put the new throttle cable on I can't get the carb barrel to get down the desired setting. At idle its almost half opened, and if I use the "brake" it only closes it to about 1/4 throttle. This is the procedure that I used to get the throttle cable installed: 1. installed cable, and quick connector on barrel arm per manual. 2. turned on Rx and Tx and went to full throttle, then turned off reciever to hold the full throttle setting. 3. clamped the cable at full throttle and turned reciever back on. This only gets me the full throttle setting, now how do I get the correct idle setting? If I set a good idle setting, then the servo won't pull the cable far enough to achieve full throttle. I'll tell you one thing, this boat is teaching me patience. I'm sticking with it though, and with your guys' help hopefully get to run it before next winter sets in. lol

ob nut

My Feedback: (1)

What kinda of transmitter are you using? Some of the cheaper pistol grip transmitter won't allow the throttle trigger to be moved. (50/50 or 70/30) If that is the case, either alter that radio or buy a better one. When I used Futaba Mag Jr's, the trigger was altered to allow only forward motion, no reverse. This was done by taking the radio apart and taking out the netrual setting peices. Also, the spring was made to pull the trigger all the way back into reverse, giving it only forward control. How long is the servo arm used for throttle? Can you fit a longer on within the radio box? Does the transmitter have ATL knobs? If so, make them so they give full throttle..

It's a begining....

ob nut

My Feedback: (1)

Another hint, the idle set screw needs to be moved out enough to allow the barrel to close all the way, but not out enough to allow the barrel to fall out. Reason is that you want the throttle control on the TX to shut the motor off. This is done by throwing the trigger into the reverse side. Idle is set by netrual settings off the transmitter..

Thompy

My reciever is an older Futuba, but does allow for 50/50 and 70/30. Its at 50/50 right now. And to add, I can't fit a longer servo arm in the radio box. So this is what i'm getting outta this. Set the FT position with the radio off and at FT, pin the cable down. Then turn the radio back on, and set the idle by moving the barrel arm? I might have to move the servo arm to get a good position too, I didn't think of that one.

ob nut

My Feedback: (1)

First off, change that throttle setting to the 70/30. Only need a bit of "reverse" to shut the motor off. Not depending on how the throw is done (push vs pull), the servo arm should be at a 30 to 45 degree angle from the servo at idle. This allows the most throw movement for the arm. Doing these two items should get a better full throttle setting. I generally work the other way than what you describe. Set idle and then work on full throttle. This was regardless of what radio being used at the time. I've only used Futaba in my 20+ years of R/C.

Thompy

Well, I believe I've got it, I moved to 70/30 and got a good setting. Just a little above 1/16 of an inch at idle, but who uses idle on a tunnel? My throttle cable clamp at the crank case is going bad, so I'll have to get another one or rig one up myself, but no worries. I can't believe such a simple part of this boat can be so frusterating. I'm sure you pro's have this stuff down pat though. Oh, and one more thing, can you get CA glue at a hardware store, or do you have to order it though tower or at a hobby shop?

ob nut

My Feedback: (1)

Only time I use idle is for starting and bringing in the boat. Make sure when reverse is used it closes the throttle fully shutting off the motor.

The CA you get from hardware or any other store than a hobby store is the same, just packaged differently. There are differences as to what type of CA you'll get. Most likely it is medium or thick CA. Doubt you'll find thin CA anywhere else besides a hobby supply outlet.

Thompy

Freak snow storm will postpone the maiden voyage I suppose, and I'm going to Athens to look for an apartment for when I transfer the next couple of days. Hopefully all goes well. I made up so weights for the nose with fishing weights and some glue, and weighed it to 4 oz. I have more weights if needed. All I need to do is get the motor started and running correctly. I'll try and keep you guys up to date as much as possible, and for the millionth time, thanks for all the help.

Thompy

Nitro can be a pain in the butt sometimes. I tried starting again today with no luck. I've got spark, new plug and a freshly charged glow heater, I've got ample compression, and fuel in the cylinder. Still no starting. I was thinking MAYBE my drill might not be spinning the crank fast enough. I'm looking for a starter as we speak and hopefully will have one before Tuesday. I wanna run this thing so bad its killing me. Good news though, I saved a bunch of money on car insurance by switching to Gieco. And I found a place to live while going to school in Athens, even though its going to cost me my left arm. lol. I've been round and round with this thing, and by the looks of the KB's simplicity it should be a snap to start, but its giving me more trouble than my .15 car engine. Oh well, tomorrows another day.

ob nut

My Feedback: (1)

If the drill had high speed it might work. The starters I use spin at a high rpm rate. Starters are dime a dozen on fleebay..

Thompy

lol.... I bought one off ebay last night, should be here by the end of the week. All I'm getting is little hits or two and thats about it, driving me insane, but I guess I'll just go down the list till I find what needs to be done to get it starter. Process of Elimation I think they call it.