K&B 1.00 Outboard Tech Questions

Just the boat engine stuff here

Moderators: Frank Klenk, SteveM

K&B 1.00 Outboard Tech Questions

Postby tylerkb12 » Sat Jan 21, 2012 2:08 pm

Hello all!

I am new to glow R/C boats (had a couple electric ones when I was younger) but not new to glow engines. I have been futzing with glow planes and cars for 20 years. I have a few questions about my new K&B 1.00 outboards which are being built as we speak :) . MY questions are as follows:

#1: I see that the recommended fuel is 25% nitro. I did not see a recommended oil type/percentage recommendation, however. Since K&B brand fuel is unfortunately not shipped outside the L.A. area, I have been poking around trying to find another brand of 25% boat formulation fuel. I have not been successful. What about 30% O'Donnell boat fuel? Is this engine sensitive to nitro to that extent or will that work fine? I love O'Donnell fuel and use it almost exclusively in cars and planes. If this fuel is acceptable, would the #7300 colder heat plug that's recommended for over 25% nitro work well?

#2: Also, since I live FAR away (100+miles) from the nearest hobby store, I would have to pay big brother's $20 EPA surcharge on each case of fuel which at that nitro percentage is extremely expensive to begin with. I'll do that if I have to but would rather not. Being a Chemistry PhD student, I know where I can get very reasonably-priced laboratory-grade Methanol and Nitromethane. All I need is some Klotz castor. Any recommendations as far as oil percentage? Or should I go with synthetic? I happen to be kind of old-school when it comes to being a castor lover :) .

#3: Would it be possible to increase the compression ratio and convert the engines to gasoline power with CDI hall-effect ignitions and 1/4-32 spark plugs? That would save BIG on fuel even over mixing it myself. Just an idea at this point but thought it would be worth asking. If it would kill my top-end power too much though, I'll stick with glow.

#4: How large of a fuel tank will I need for each 1.00ci engine? I was thinking 1000cc would be about right, but please let me know. What kind of running time could I expect from a Liter of fuel?

#5: I did not see in the picture a muffler of any sort on the engine. It looks as though the exhaust goes out the back of the sleeve into the casting for the lower unit and out the four holes drilled underneath. I am not worried about noise as I live about 25 miles from a traffic light and have my own lake access with dock and a nice lake about 1.5miles across to have fun on. I am concerned, however, that the instructions say that the engine is designed to run with muffler pressure into the tank. Is there a pressure tap nipple somewhere on the engine? If not, where do I drill and tap?

#6: I also noticed that there is a servo-operated mixture control for the engine similar to a ducted fan engine. Any recommendations on how far from the engine is acceptable to mount it, and/or height in relation to the carburetor?

#7: Almost done! :wink: Is it acceptable to use a fuel tank designed for airplanes? Is there really any difference? I have not been able to find a tank 1000cc+ that is specifically for boats.

Thanks for any help!

Tyler
tylerkb12
 
Posts: 2
Joined: Sat Jan 21, 2012 1:40 pm
Location: Bemidji, MN

Postby SteveM » Sun Jan 22, 2012 4:38 am

1. I used Byron 25% nitro fuel in my K&B outboards and never had any problems. I liked to add 1 ounce of Sia AA castor oil to my gallon jugs as a bit of extra lube insurance.

2. Mixing your own fuel is a dangerous thing and I recommend you buy instead. If you absolutely must, try 18% to 20% oil and you can use a mix of castor and synthetic. Sig sells AA castor oil.

3. The K&B motors are not designed to run gasoline and if you want economy then buy a proper gas motor. There are several out there and a Google search should help.

4. Tank size depends on how long you want to run. I only ever raced and we only needed fuel for 6 race laps and a couple of warm up laps. In m5 3.5cc I used an 8 oz tank.

5. The motor exhausts through the lower unit and there should be a brass nipple pressure fitting already installed.

6. I've never used a 3rd channel mixture control and I doubt it makes any difference where it is mounted.

7. Sullivan airplane fuel tanks are fine.
SteveM
 
Posts: 242
Joined: Mon Nov 20, 2006 10:33 am
Location: Ottawa, Ontario, CANADA

Postby tylerkb12 » Sun Jan 22, 2012 12:18 pm

Thank you so much Steve! I am well aware of the dangers of the chemicals involved with mixing and with the prices I can get on 99.95% pure methanol and nitromethane I think I'm going to go ahead and do it. I work in a lab all day and I am extremely careful and safety conscious. I even asked the head of the Chemistry department if I could mix it under the big fume hood in our organic Chemistry lab and he said no problem. Thanks for all your help!

Cheers,
Tyler
tylerkb12
 
Posts: 2
Joined: Sat Jan 21, 2012 1:40 pm
Location: Bemidji, MN

Re: K&B 1.00 Outboard Tech Questions

Postby Scott11 » Thu Oct 10, 2013 3:40 pm

I was just wondering if I could put a motor this size on a 28" aquacraft vs1 tunnel boat? It may be to heavy. I haven't bought either the hull or motor yet, but I don't want to limit my possibilities by buying something that is hard to work with
Scott11
 
Posts: 6
Joined: Thu Oct 10, 2013 3:28 pm

Re: K&B 1.00 Outboard Tech Questions

Postby SteveM » Fri Oct 11, 2013 4:49 am

Scott11 wrote:I was just wondering if I could put a motor this size on a 28" aquacraft vs1 tunnel boat? It may be to heavy. I haven't bought either the hull or motor yet, but I don't want to limit my possibilities by buying something that is hard to work with


The bottom line is NO, you cannot use this large outboard on a hull designed for a 3.5cc (0.21 cu in) outboard.
SteveM
 
Posts: 242
Joined: Mon Nov 20, 2006 10:33 am
Location: Ottawa, Ontario, CANADA


Return to Marine Engine Topics

Who is online

Users browsing this forum: No registered users and 11 guests

cron