tinsink

I have a new killer bee that a friend gave to me. it has a prop with it. I think a 5" dia stock prop. I can't get it to run right. it just sputters. When I try to lean it out it just stops.
i'm using 15% nitro. Any suggestions? I'm not sure about the details of mounting the engine and tank so I just did it with the tank at the same level as the air intake. Also, I did not drill a hole in the fire wall adjacent to the air intake, but there seems to be sufficient room for air
from the indent for the fuel line.

combatpigg

My Feedback: (3)

There are many reasons for your engines' symptoms. Just about every basic need for a 2 stroke to run correctly can be compromized in a combination of ways to bring about this kind of trouble. I like to start people out with a leak down test of the piston/liner fit. Prime the piston, bring it up on compression and look closely into the exhaust ports for air bubbles. A good engine will maintain a solid seal for at least 5 seconds. The crank can be loose in the crankcase causing a pressure leak. If these problems are what plagues your engine, then it is time to look at this engine as not much more than a "parts" engine. Sometimes you can get away with a good cleaning, like you would clean a gun[with bore brushes and HOPPES SOLVENT], reset the rod, and replace the tank/ air inlet o-ring and needle valve seal, and of course a fresh glow plug. Some compression can be lost past a bad glow plug seal also.

burtcs

First, I have never used a Killer Bee from Cox/Estes. I make my own from bits and pieces. Both are NFFS legal for free flight use. If I am using a RV engine for competition I use 60% nitro with an once of caster added per quart. People look at me like l'm insane but the difference in RPM between 30% and 60% is only about a 1000 RPM. The nitro smooths out the run - thats all, it will not blow your engine. I use High compression heads (legal) and vary the head gaskets for the day, usually 1-3. I use APC 5.5-2 or 6-2 depending on the model. I also lap the piston and cylinder to remove the tight spot at TDC - yes they start hard but why waste HP jamming the piston into the tight cylinder. Spring starters don't weigh much and they solve the starting problem

For sport flying and RC work I will use 20-35%, The engines run fine, they stay warm and don't seize up because they got cold. The low compression heads work OK and I've got more of them. The only exception is 1/2A RC Texico work 10% and 3-4 gaskets, 8-4 props.

You didn't say what your using the engine for but that's what I do. Have fun

HTH - Steve B.

tinsink

Thanks for the info guys.

I assumed that because it was a brand new engine that there is no need to go through the assembly and fit for proper construction. I guess that I'll go through the whole nine yards
and figure out if it is any of those issues.

Rich

combatpigg

My Feedback: (3)

Even though it is a new engine, there can be a stacking up of out of tolerance parts fits that can make a new engine a lemon . The checks that I gave for you to do can be done during a TV commercial, without dismantling anything. If the engine is way too tight, it will only run cool and rich. A thorough dismantling and inspection might not turn up anything if you don't know what to look for. It might be smarter to just set the engine up on a bench somewhere and run several tanks of fuel through it while you observe it.

Dukester

My Feedback: (31)

tinsink,

I had a sort of similar problem with a product .049. Even though there appeared to be a small amount of clearance behind the intake, it wasn't enough. It would run haltingly for a short time, then sputter and die. I put some washers under the mounting screws to inctrease the spacing for airflow and my troubles went away. This is pretty easy to check right off the bat.

Duke

tinsink

Hey Dukester,

I'll look into that factor also. I wish that there was some type of instructions
to guide me through the installation process. Maybe there is and I don't know
about it. Any info on instructions that may come with a Killer bee?