Old K&B 7.5...20+yrs sitting...genl help

[frankdoman]

This motor has been sitting for 20+ yrs in the basement...now want to see if it will fire up. Should I start by taking out the glow plug and seeing if the parts will move with no compression, and can I open up the lower unit to see if the flex drive shaft will turn ? I assume get a 1.5V battery from a hobby store to check the plug glow? Is this a 2 stroke and what gas/nitro to try ? Just looking for a few pointers on where/how to get started on the motor itself, and then will also get to the servo/rc parts...thanks. A REAL NEWBIE here. A few motor pics attached.

F

 

[HOTWATER]

Wow! That thing is a trip!! Is that thing electric pwered too in case the motor stalls? That yellow prop is great for making milkshakes with...LOL! Just kidding! I guess with the age of that motor and since it has been sitting for so long, I would probably start with a teardown of parts, see what things look like inside... bearing, piston, sleeve, etc...a good soaking of parts in a parts cleaner.

 

[jetpack]

Dang! Yeah what's with the little prop? Is that some kind of Speed-O-Meter?

I dig the roll-over bar, great for recovering from them log jumps!

All kidding aside, if you don't want to rip it all down you could close the piston in the exhaust port, work in some MEK through the carb, close it, rotate and shake the whole works to soak it around inside, and before you turn the bearings, empty it out the exhaust port, flush it again a few times, and then start working on turning it a little at a time.

Nothing inside that motor will get hurt with MEK, even the plastic bearing cages. It will however eat anything thats around it, maybe even the carb O-ring...dunno, but I would dis-mount it and remove the prop and as much as you can from it.

Some might bawlk at this, but if you're in a hurry you can try it. Just new fuel would work as a flushing agent, but MEK is cheaper and carries no oils so it will flush more aggressive. Kerosene will work also, maybe lamp oil if you have it.

Maybe spread out the flushing cycles over a couple days too, and give the flush time to loosen things up.

Warming the whole motor in the oven first will also give it a better start, but don't go crazy with the temp, just past hand hot will work real well. Nothing over 200, and even well below that is fine.

Just be safe of course and don't be pouring MEK all over the hot stove...LOL! Use some rubber gloves.

Welcome to the club, Frank.

 

[frankdoman]

Wow, u guys are really funny about seeing this old boat. Yep, the little extra prop is to get her back in case you run outa gas or the engine dies, and it has it's own prop shaft steering servo, battery, etc...I have no idea what the handle/roll bar thing is and there is a cable running up to the top inside the channel aluminum also attached to a servo, but nothing at the end up in the roll bar except a spring like from a fountain pen, and MAYBE something else snapped into the channel up at the top that is now missing.

Anyway, it is an oldie for sure, and I appreciate the helpful hints about trying to start it up. I will do some general cleaning and take off stuff that I can on the bench. I assume from all I have read that a std 1.5 V glow plug battery is what I need, and try some fuel which is in the 15-20 range ? Like I said, neither one of us has ever seen one of these run, and my buddies dad made this boat maybe 25 years ago and it has been in a box in his basement since then. Thanks for the help. I have the feeling I will be back on with more ???

Frank

 

[HOTWATER]

Wow, u guys are really funny about seeing this old boat. Yep, the little extra prop is to get her back in case you run outa gas or the engine dies, and it has it's own prop shaft steering servo, battery, etc...I have no idea what the handle/roll bar thing is and there is a cable running up to the top inside the channel aluminum also attached to a servo, but nothing at the end up in the roll bar except a spring like from a fountain pen, and MAYBE something else snapped into the channel up at the top that is now missing.
Anyway, it is an oldie for sure, and I appreciate the helpful hints about trying to start it up. I will do some general cleaning and take off stuff that I can on the bench. I assume from all I have read that a std 1.5 V glow plug battery is what I need, and try some fuel which is in the 15-20 range ? Like I said, neither one of us has ever seen one of these run, and my buddies dad made this boat maybe 25 years ago and it has been in a box in his basement since then. Thanks for the help. I have the feeling I will be back on with more ???

Frank

I think that roll bar thing is actually a ski tower to pull a squirrel on water skis!

Yes, you need a glow driver for the plug and some 40% ...if you can get it fired up.

Keep us posted. A video of it running (with the squirrel, of course) would be excellent! Just make sure you bring plenty of nuts...

 

[HOTWATER]

Wow, u guys are really funny about seeing this old boat. Yep, the little extra prop is to get her back in case you run outa gas or the engine dies, and it has it's own prop shaft steering servo, battery, etc...I have no idea what the handle/roll bar thing is and there is a cable running up to the top inside the channel aluminum also attached to a servo, but nothing at the end up in the roll bar except a spring like from a fountain pen, and MAYBE something else snapped into the channel up at the top that is now missing.
Anyway, it is an oldie for sure, and I appreciate the helpful hints about trying to start it up. I will do some general cleaning and take off stuff that I can on the bench. I assume from all I have read that a std 1.5 V glow plug battery is what I need, and try some fuel which is in the 15-20 range ? Like I said, neither one of us has ever seen one of these run, and my buddies dad made this boat maybe 25 years ago and it has been in a box in his basement since then. Thanks for the help. I have the feeling I will be back on with more ???

Frank

I think that roll bar thing is actually a ski tower to pull a squirrel on water skis!

Yes, you need a glow driver for the plug and some 40% ...if you can get it fired up.

Keep us posted. A video of it running (with the squirrel, of course) would be excellent! Just make sure you bring plenty of nuts...

 

[frankdoman]

I love the squirrel thing, and a tow tower could be a good guess ! We are the nuts for even trying to get this running I think, but should be fun.

Really 40% fuel? I saw many sites talking about > 25% is pretty risky stuff, but I have no idea.

To heat up the glow plug do you just attach the + to the little connector pin with a clip, and the - to the body of the plug or the motor if still on the motor? I remember as a kid that others with those little planes did something like that, and just making sure. I think they had little alligator clips to attach it, and is this still how it is done ?

 

[HOTWATER]

I love the squirrel thing, and a tow tower could be a good guess ! We are the nuts for even trying to get this running I think, but should be fun.
Really 40% fuel? I saw many sites talking about > 25% is pretty risky stuff, but I have no idea.

To heat up the glow plug do you just attach the + to the little connector pin with a clip, and the - to the body of the plug or the motor if still on the motor? I remember as a kid that others with those little planes did something like that, and just making sure. I think they had little alligator clips to attach it, and is this still how it is done ?

If the boats name is Twiggy(the famous water skiing squirrel), it might be a good guess! LOL!

25% is fine to use. I personally use Marvel Mystery oil after I am done running for the day. A few drops in the glow plug opening (with glow plug removed of course) and a couple in the carb opening.

Here is a pic of a glow plug driver. It has a nicad inside of it and can be charged without taking the battery out. Hope this helps a little!

Don't worry, sometimes I thinks I'm nuts too!!

 

[frankdoman]

I love the squirrel thing, and a tow tower could be a good guess ! We are the nuts for even trying to get this running I think, but should be fun.
Really 40% fuel? I saw many sites talking about > 25% is pretty risky stuff, but I have no idea.

To heat up the glow plug do you just attach the + to the little connector pin with a clip, and the - to the body of the plug or the motor if still on the motor? I remember as a kid that others with those little planes did something like that, and just making sure. I think they had little alligator clips to attach it, and is this still how it is done ?

If the boats name is Twiggy(the famous water skiing squirrel), it might be a good guess! LOL!

25% is fine to use. I personally use Marvel Mystery oil after I am done running for the day. A few drops in the glow plug opening (with glow plug removed of course) and a couple in the carb opening.

Here is a pic of a glow plug driver. It has a nicad inside of it and can be charged without taking the battery out. Hope this helps a little!

Don't worry, sometimes I thinks I'm nuts too!!

 

[frankdoman]

I love the squirrel thing, and a tow tower could be a good guess ! We are the nuts for even trying to get this running I think, but should be fun.
Really 40% fuel? I saw many sites talking about > 25% is pretty risky stuff, but I have no idea.

To heat up the glow plug do you just attach the + to the little connector pin with a clip, and the - to the body of the plug or the motor if still on the motor? I remember as a kid that others with those little planes did something like that, and just making sure. I think they had little alligator clips to attach it, and is this still how it is done ?

If the boats name is Twiggy(the famous water skiing squirrel), it might be a good guess! LOL!

25% is fine to use. I personally use Marvel Mystery oil after I am done running for the day. A few drops in the glow plug opening (with glow plug removed of course) and a couple in the carb opening.

Here is a pic of a glow plug driver. It has a nicad inside of it and can be charged without taking the battery out. Hope this helps a little!

Don't worry, sometimes I thinks I'm nuts too!!

 

[frankdoman]

I love the squirrel thing, and a tow tower could be a good guess ! We are the nuts for even trying to get this running I think, but should be fun.
Really 40% fuel? I saw many sites talking about > 25% is pretty risky stuff, but I have no idea.

To heat up the glow plug do you just attach the + to the little connector pin with a clip, and the - to the body of the plug or the motor if still on the motor? I remember as a kid that others with those little planes did something like that, and just making sure. I think they had little alligator clips to attach it, and is this still how it is done ?

If the boats name is Twiggy(the famous water skiing squirrel), it might be a good guess! LOL!

25% is fine to use. I personally use Marvel Mystery oil after I am done running for the day. A few drops in the glow plug opening (with glow plug removed of course) and a couple in the carb opening.

Here is a pic of a glow plug driver. It has a nicad inside of it and can be charged without taking the battery out. Hope this helps a little!

Don't worry, sometimes I thinks I'm nuts too!!

 

[frankdoman]

OK, most of the old engines seem to take the 1.5 V battery charger for the glow plug from what I can see on the various web pgs...can this old motor really take one of these newer type charger/driver for the glow plug? I would hate to burn the thing out on the first try. What should I expect to pay at a hobby shop for a driver/batt for this old glow plug please?

F

 

[HOTWATER]

OK, most of the old engines seem to take the 1.5 V battery charger for the glow plug from what I can see on the various web pgs...can this old motor really take one of these newer type charger/driver for the glow plug? I would hate to burn the thing out on the first try. What should I expect to pay at a hobby shop for a driver/batt for this old glow plug please?
F

Tower Hobbies has tons of different glow starters to choose from. The rechargeable ones start at around $14.00 and can go up to $30.00. They also carry one for $7.00 that you can just drop a C cell into and you're good to go. That is what you really need. Forget about the alligator clips...you will just get frustrated trying something like that. Also, I hope you have a starter motor for it (and a 12 V. battery). The old school way of wraping a cord around the flywheel a pulling it will not work here. You will need some tork to get that thing to fire up...believe me! Here is a pic of the type of starter motor you will need, if you don't already have one...and another pic of a hand crank fuel pump. You need at least something like this to get the fuel into and out of the tank when you are done running for the day...

 

[frankdoman]

Good advice....I appreciate it. Will make a stop to the hobby shop and see what they have and at least now I have some idea what to look for and what to spend...Thanks!

F

 

[HOTWATER]

Good advice....I appreciate it. Will make a stop to the hobby shop and see what they have and at least now I have some idea what to look for and what to spend...Thanks!
F

No problem Frank. Keep us posted on how things are going with it or if you need a walk through on starting it up.

Good luck!

 

[frankdoman]

The local hobby shop is a joke...all about planes only and a few plug and play boats, and nobody in there old enuff to even know what K&B is....so I will get stuff online I guess from Tower. The fuel line, pressure line from the muffler fitting, water circulation line, etc>>>do you think they are in the S, M, or L size of lines that I see on their site, and I guess silicone tubing is what I need for all these since it is nitro fuel? Thanks again.

Frank

 

[John Kubitz]

When you get the boat running you should consider up-grading the radio. If the radio is on 75mhz it is the old wide band type. I became obsolete in 1991. If it is on 27mhz it is still ok to use.

 

[frankdoman]

When you get the boat running you should consider up-grading the radio. If the radio is on 75mhz it is the old wide band type. I became obsolete in 1991. If it is on 27mhz it is still ok to use.

John, does obsolete mean hard to find parts, illegal to use, or just an old system that is much less reliable and a pain for some reasons? I am not sure, but I think I did see a sticker on it somewhere with 72.xxx, or 75.xxx on it and I am guessing it is the older mhz if that was the std. back in the 70s or early 80s when I think my buddies Dad made this...or were both 75 and 27 mhz used back then ?

Thanks, Frank

 

[John Kubitz]

When you get the boat running you should consider up-grading the radio. If the radio is on 75mhz it is the old wide band type. I became obsolete in 1991. If it is on 27mhz it is still ok to use.

John, does obsolete mean hard to find parts, illegal to use, or just an old system that is much less reliable and a pain for some reasons? I am not sure, but I think I did see a sticker on it somewhere with 72.xxx, or 75.xxx on it and I am guessing it is the older mhz if that was the std. back in the 70s or early 80s when I think my buddies Dad made this...or were both 75 and 27 mhz used back then ?

Thanks, Frank

Both 27mhz & 75mhz are legal for surface (boats & cars) however the 27mhz band is a shared frequency with aircraft. Most of the aircraft on 27mhz are the inexpensive ready-to-fly type. Your radio looks like a pre 1991 FUTABA. The wide band radios (on 75mhz) are not legal after Jan,1 1991. The 72mhz band is only for aircraft. After you get everything working i would do a post looking for a good used current 75mhz radio. If you are just going to run the boat for fun that would be the most cost effective way to go.

 

[frankdoman]

When you get the boat running you should consider up-grading the radio. If the radio is on 75mhz it is the old wide band type. I became obsolete in 1991. If it is on 27mhz it is still ok to use.

John, does obsolete mean hard to find parts, illegal to use, or just an old system that is much less reliable and a pain for some reasons? I am not sure, but I think I did see a sticker on it somewhere with 72.xxx, or 75.xxx on it and I am guessing it is the older mhz if that was the std. back in the 70s or early 80s when I think my buddies Dad made this...or were both 75 and 27 mhz used back then ?

Thanks, Frank

Both 27mhz & 75mhz are legal for surface (boats & cars) however the 27mhz band is a shared frequency with aircraft. Most of the aircraft on 27mhz are the inexpensive ready-to-fly type. Your radio looks like a pre 1991 FUTABA. The wide band radios (on 75mhz) are not legal after Jan,1 1991. The 72mhz band is only for aircraft. After you get everything working i would do a post looking for a good used current 75mhz radio. If you are just going to run the boat for fun that would be the most cost effective way to go.

Understood John...thanks for clarifying. NOTHING about this OLD boat, r/c would surprise me, it is DEFINITELY pre '91...thanks for the knowledge and advice...the people on this site know so much I am amazed....Frank