justplanecrazynz

Hi I have a K&B 45 sportster engine and I want to know how to get it running without it coughing and spluttering. Can someone help. I think my nitro is oo old, and the filter is too old and has proberly got clogged up over time. It has got a brand new glo plug in it but tends to stall after about 5 mins in the air and has caused a few near misses with the ground. I want to sort this out before I kill my plane.

aussiesteve

I'm not particularly familiar with K&B as such but I think you have started to answer the question yourself.

Is it a new installation, has the plane worked OK with a different engine, Was the engine OK in another plane?

Fresh fuel & Make sure your fuel system is clean and unclogged. If it is an older engine or has been sitting around for a while (Or theplane is the same), make sure the fuel lines are in good condition, everything is well sealed then start trying to tune it. there are numerous threads here to help with the tuning.

Many people try to tune out installation problems or system blockages - they are not usually successful.

huck1199

The 45 sportster likes 20 % oil (use copius castor) as it is plain bearing. It may be heating up if you are using low % synthetic oil content. They take a while to break in, if this is a 'new' old engine you may want to increase the castor even more.

wcmorrison

My Feedback: (2)

Yes, it sounds like it is getting hot and ceasing in flight. So get some Castor and doctor your fuel up with some extra Castor oil.

Cheers,

Chip

justplanecrazynz

I have just put a new fuel tank in the plane, gave it run today, running better but i still think it is the gas and the filter as it pretty old now. someone on flying giants reckoned that the carb could be problem as he siad he had a k&b and he said the carb had to be kept clean all the time.

justplanecrazynz

not a new engine..............just want to know also if i need to keep using castor or just 20% syn oil? Can i up the nitro to 15% or leave it at 10%? the more i can find out the sooner i crack it and ge that motor running sweet.................

turbo.gst

My Feedback: (8)

In my experience with the Sportsters, you want 20% oil even after break-in. The ones I have seen run on lesser oils just don't survive. I think they need castor oil as well. Given a diet of proper lube and castor oil has rewarded me with 20 years of service from my first Sportster. I really like the engine and have bought several more. I hope you enjoy yours as much as I have.

turbo

huck1199

If you feed it the right diet it will reward you with a long steady life. I use Morgan Omega 15% nitro which I hear is 18% oil. I add 4oz Klotz Benol caster per gallon. So my mix is about 20% oil. The label says 'caster/Synthetic mix' They don't say what the percentages are (they list caster first), but the added caster seems to work OK for me. The K&B carbs are no more finiky than any other. They all must be kept clean as you allready know. The low speed eccentric cam dial is sensitive so move it very little each trial during tunning. I think clockwise rotation richens the mix, but I'm not sure I remember. But you didn't mention an idle problem so you probably have it dialed in. I have been using Fireball std plugs with no problem. They are one of the original brands and sell for about half the snazzy name brands.

jeffie8696

You have some great advise here. I myself just recently purchased a nice .45 and I just love it. I use Sig 20% all castor 15% nitro and the engine really loves it. you can actually hear it run smoother on it. Mine is only a .45 but it has an identity problem , it thinks and acts like a .60 Heck it's as big as one on the outside.

I just ran across my last dyno numbers for my .45 it turned a Master Airscrew 11X6 to 12,200 on Sig 15% Nitro 20% all castor. And it idled at 2300 (I didn't even try to adjust that ) And flip started at idle. At that moment I fell in love with it. [sm=teeth_smile.gif]

Razor-RCU

My Feedback: (50)

Pretty good numbers there on the .45 ! I have always had it in my head to get the K&B Sportster-65 since I had one when I was about 16 and never had it running properly. I refuse to be beaten! The 45 Sportster is one I have always wanted to try also- I love K&B period.

NM2K

My Feedback: (14)

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There is nothing magical or special about a K&B engine.

The Sportster series by K&B requires an extensive break-in. Most folks give up before the engine is completely broken-in because they are not aware of the engine's needs. Like the castor oil lube in the fuel that others have mentioned.

All glow engines, by any manufacturer, need clean fuel. K&B is no different in that regard. What size is the engine? Which prop (size) are you running on the engine? If the prop is too large, it can cause overheating, even if the engine is broken-in properly and running the correct fuel.

You did the right thing by asking your questions on this forum. Now give us a little more information to work with in our analyses and we will do our best to get you flying properly.


Ed Cregger

jeffie8696

Looks like I have 2 more coming to live at my house. A .20 and a .28.

NM2K

My Feedback: (14)

I have two .28 Sportsters. They are good engines and not wimpy in power, for plain bearing engines. I never could get the one I have to run reliably on a prop larger than a 9x4. It's powering my wife's Ben Buckle Red Zephyr old time R/C assist model. The model weighs 7 pounds and scoots right along with the K&B .28 Sportster mounted up front. Once broken-in (yeah, I know I sound like a defective phonograph record) they are great little engines. I need to pick up a .45 one of these days, just to complete the collection.


Ed Cregger

jeffie8696

Oh I reccomend the .45! Mine just rocks. Likes high nitro. Have you tried some 15% nitro with 20% castor in the .28? My .45 came alive on it and it turns a really big prop very nicely. I would do some more experimenting and find out if you can get more power with a plug change too. If while my engine is running I turn up the amperage on my glow driver and it gains a few rpms I go to the next hotter plug. Or more nitro as it will do the same thing.
UPDATE: The K&B .20 arrived today. Very dirty and hadn't been run in a long time. Cleaned it up, ran some 5% nitro 20%castor through it and Zoom!! Needs one hole rethreded in the muffler wich seems to be a recurring problem with the Sportsters. But it runs great!! Want's more nitro like it's big brother . [)]

justplanecrazynz

I have a .45 sporster running a 10x7 prop and running a brand new filter now and gas tank. I am running 15% nitro and 18% oil. the oil is 70% synthetic and 30% castor. have only just replaced filter and tank in the weekend just gone, and haven't had a chance to run it yet to c if that has made any difference.The engine is not new, have had it sin the ealy 90's and i built the plane its in about then. i have been buidig for over 10 years off and on, but only flying for 3

justplanecrazynz

I was talking to a guy at my club yesterday and he thinks that 30% nitro would have it purring. I refuse to be beaten by my engine so i will just keep at till i get it right.