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K+B outboard tough to start

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K+B outboard tough to start

Old 09-13-2007, 03:12 AM
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bensidus197217
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Default K+B outboard tough to start

I have to admit I am nitro challenged. I have a K+B 3.5 outboard or as I was informed a .21 cubic inch with a gold fitting black carburator, I could not get this thing to fire except for brief bursts after which I would end up floading the carb, I think the fuel dripping out the exhaust is a good indication. I have been using a drill with a socket for posative grip to start it trouble is as soon as it flashed the nut spun off and I think the flywheel freewheeled at that point which I think is the reason the motor stopped I did set the mixture screw to 4 to 5 turns so from what I was told the mixture should be set near there, I then made up a cone starter for my drill but there wasn't enough posative grip it seemed , so it would stop at times during cranking. Once again I thought I was smart enough to figure this thing out and once again I was wrong, I turned the motor over by hand and noticed it was very tight at tdc so tight it felt like it was jamming, so I pulled the engine apart and noticed no discolouration from heat or carbon, looked brand new. I pushed the piston and liner out by forcing the piston up till it stuck then pushed the whole package out, I sanded the liner so the piston was able to push through freely, and guess what ? Now I have very little compression so I'm going to have to replace the above parts.

QUESTIONS: 1. Can a cordless drill spin this engine fast enough to start it effectively?
2. When I get my new piston and liner how do I start and break it in, I need every tiny detail about this please including everything that can go right or wrong?
3. Is it possible the last owner of this motor could have broken it in wrong and caused the piston to become too tight in the bore?
4. Can cranking the engine too slow cause the engine to be difficult to start?


Thanks Jim
Old 09-13-2007, 05:49 AM
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Dan S
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Default RE: K+B outboard tough to start

yes, you are supposed to have a tight fit at TDC with an ABC K&B engine, unfortunately you removed it when you sanded it. your drill may not have enough torque, get yourself a good starter motor, also make sure you are starting it in the right direction.

maybe the last owner did not breakin the engine or the breakin was not complete, however you want it to be tight at TDC.

Again it is not I fast or slow you can crank the engine but torque needed.

4 to 5 turns out will be fine than make adjustment 1/8 at a time.

Dan.
Old 09-13-2007, 07:26 AM
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bensidus197217
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Default RE: K+B outboard tough to start

Hi Dan:
I guess the times it would jam would be the times it was going to fire? The problem with my cone starter on my drill wasn't torque it was how well the rubber griped the cone which was poorly. The drill has plenty of torque but I don't know how critical speed is on these engines. Thanks Jim
Old 09-13-2007, 07:37 AM
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Default RE: K+B outboard tough to start

Starting the motor with a socket on the flywheel nut is not a good thing and you saw the results when the nut came off.

Get a 12 or 24 volt high torque starter, they have the proper starting cone and will be easier.

also have your starter spinning before you put it on the flywheel, this prevents a lot of slipping.

You said you had the Gold fitting black carburator?

Can you put some pics?
what carb do you have on? Gold, Black?

Dan
Old 09-13-2007, 07:37 AM
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Default RE: K+B outboard tough to start

ORIGINAL: bensidus197217

Hi Dan:
I guess the times it would jam would be the times it was going to fire? The problem with my cone starter on my drill wasn't torque it was how well the rubber griped the cone which was poorly. The drill has plenty of torque but I don't know how critical speed is on these engines. Thanks Jim
Jamming the starter can happen on the older K&B engines. I have a 3.5 aero engine (very similar to the outboard power head but without the PTO or flywheel) that would lock up so tight that I had to smack the prop to free it. After 15 or 20 runs it would only lock the starter occasionally, but it was still very tight. Do yourself a favor and buy a proper starter. In addition to having the right rpms, the design is probably better for applying pressure to engage the rubber insert on the flywheel. The engine will loosen up with heat, the liner will expand faster than the piston, so you could heat it a bit before starting.
Old 09-13-2007, 07:45 AM
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bensidus197217
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Default RE: K+B outboard tough to start

I can send some pics but I'm not sure how to do it on this forum. Thanks Jim
Old 09-13-2007, 09:09 AM
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Default RE: K+B outboard tough to start


ORIGINAL: bensidus197217

I can send some pics but I'm not sure how to do it on this forum. Thanks Jim
You can find instructions for posting pictures [link=http://www.rcuniverse.com/forum/m_2629917/tm.htm]here[/link].
Old 09-13-2007, 09:17 AM
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Default RE: K+B outboard tough to start

QUESTIONS: 1. Can a cordless drill spin this engine fast enough to start it effectively?
2. When I get my new piston and liner how do I start and break it in, I need every tiny detail about this please including everything that can go right or wrong?
3. Is it possible the last owner of this motor could have broken it in wrong and caused the piston to become too tight in the bore?
4. Can cranking the engine too slow cause the engine to be difficult to start?
I think number 1 has been answered already. Buy a starter and 12v battery.

Writing a comprehensive answer to number 2 will take someone a bit of time, especially if they're going to cover every detail. One of the best things you could do would be to find someone in your area, even if they are a couple hours away, and spend some time at the pond with them.

Breaking in an engine wrong will usually result in the piston/liner fit to be too loose, so the tightness in your engine was not due to anything the former owner did.

Cranking too slow will make an engine harder to start. For years I only ran smaller engines, so 12 volts worked fine. When I started running some larger ones, such as an OS .81, 12 volts just wouldn't cut it. So, I made the switch to 24 volts for my inboards. The interesting thing is that my .45 inboards also start much easier now that they're spinning faster.
Old 09-14-2007, 09:23 AM
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Default RE: K+B outboard tough to start

Does 24volts work with every starter out there for brief starting purposes?

Ryan
Old 09-14-2007, 10:31 AM
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Default RE: K+B outboard tough to start

I believe there is a few people here that use their 12Volt starter on a 24Volt system, it does work but the life expectancy of the starter will be shorter.

Dan.

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