RCU Forums

RCU Forums (https://www.rcuniverse.com/forum/)
-   Beginners (https://www.rcuniverse.com/forum/beginners-85/)
-   -   K&B engines (https://www.rcuniverse.com/forum/beginners-85/9837333-k-b-engines.html)

Idasam 06-30-2010 08:13 PM

K&B engines
 
I was wondering if anyone here has any experience with K&amp;B? I read through the reviews and they all looked good. The first review complained that the <font face="tahoma,arial,verdana">K&amp;B .48 ABC W/MUFF was a bit weak. The engines look nice, but looks can be deceiving. I was looking at buying an Evo. and I've heard nothing but bad things about them, and Evos. are about the nicest looking engines out there. So looks aside anything that you can tell me about K&amp;B would be great.
</font>

tessmar 06-30-2010 08:19 PM

RE: K&B engines
 
I have an old K&B 45 that came with a used plane. It was totally gummed up when I got it, but a solvent soak was all it took to get it running. Parts are readily available, and while a bit crude in design and not the most powerful motor in its class by far, its performance is acceptable and I have had good responsiveness by the company. its on the shelf right now because the two piece muffler can came apart in mid air and I have not yet replaced it (again, the company assures me the parts are available and there are exploded parts diagrams on their web site). For the price I think they are totally OK

DeferredDefect 06-30-2010 09:01 PM

RE: K&B engines
 


Hello!

I have a K&amp;B 60 that was in a used Cub, and, after an hour of struggling, got it to run. It has plenty of power, but that's it. Quality is poor, stock muffler (oxymoron) continually loosened, and the idle was brutal. It's going in a boat or something, as I'd never trust one in the air after my experience with it. (Cub now has a OS FS-70, never gave me problems!)  

I do not own any other K&amp;B engines, newer ones might be better, but most of our club avoids them.

</p>

Minnreefer 06-30-2010 09:15 PM

RE: K&B engines
 
From my personal experience and from what I have heard, some people LOVE K&B engines and some hate them, I had a K&B outboard engine, had a lot of issues getting it to run well, but I was also young at the time. If you don't have a ton of experience with engines, I would stay with OS or o with an engine that other members of the club know, they are more likely to help you get it going great.

Gray Beard 06-30-2010 09:17 PM

RE: K&B engines
 
They are very good engines. If you want one to get a hop up job then Clarence Lee is still working on them. You can find his adds in MAN. Great person to deal with too. It's one of the over looked engines and well worth the money. Looking cool isn't any way to look at it. I like the SK line of engines sold through Kangke and they aren't polished at all, they just run good. I only say that about the .90 because it's the only size I have used though. After several of them I like them better then the OS.

jeffie8696 06-30-2010 09:38 PM

RE: K&B engines
 
Ihave had good luck with the Sportsters. I have a .28 ready to install in my SIGBF-109. It is very light and gives good power to weight.

JohnBuckner 06-30-2010 09:47 PM

RE: K&B engines
 
You have to be careful when talking about K&B engines as the variety and modifacations over the years has been hugh and there was a time back when that you could go to any field and see almost nothing else.

So having said that I am going to address the .48ABC Screaming Fortyeight. This engine along with the Screwhead Sixtyones were the last ditch effort by the original family owned company to compete with the imports around fourteen years ago.

I feel both were failures and the company was finally closed down in Lake Havasu Az. It was bought by Randy L. of RJL who seems to have sold mostly existing stock of these two engines and there may have been some new production runs.

I purchased two of the .48's and two of the Screwhead .61's when the first hit the stores.
The Screwheads had a totally new porting senario and they were superbly powerful for a while and I completly enjoyed flying turnaround pattern with them. That is untill both at around ten hours blew the complete top of the engine off at the crankcase.

The forty eights were a completly new design unlike the Screwheads with modified liteweight crankcases and their major problem is they shared the old rather crude carbs used by all K&B's.

These carbs all relied on the rotating spray bar for midrange control and in my opinion they just never got it quite right. I originally purchased those Screaming 48's to use on a twin but after first running them that I did not care to use them in that kind of application. In the years since they have served yeoman duty in variety of airplanes and currently are back in the boxs, holding not much interest for me.

Now if you want a truly spectacular engine with superb throttling and all around performance then try one of the new AX line like the 55 for example.


John

All just an honest opinion as a past user of those engines.




JohnBuckner 06-30-2010 09:52 PM

RE: K&B engines
 
Please note the Sportsters which include the .20, .28, .45 and .65 are completely different engines from the Screaming ..48 and there is no common connection other than the rotating spraybar carb.

John

bigedmustafa 06-30-2010 10:07 PM

RE: K&B engines
 
I have a pair of recently acquired new-in-the-box K&B Screamin' .48 engines. I bought one off of E-Bay; it was made before K&B was sold to MECOA/RJL. The second is a brand new one ordered from MECOA. The two engines are identical and MECOA doesn't appear to have altered any part of the original design.

We've been doing some non-sanctioned club pylon racing over the last couple of seasons running .40 to .48 2-strokes of all makes. Last year's winner was an old .46 FX with new bearings. This year's winner was a K&B Screamin' .48 engine. The .46 AX engines are always very competitive, but they haven't won. The Thunder Tiger Pro .46 is also at the top of the class for truly competitive power.

I haven't had a chance to fly my Screamin' .48s yet, but I'm looking forward to taking them for a whirl.

http://www.mecoa.com/kb/48/48.gif

bruce88123 07-01-2010 03:23 PM

RE: K&B engines
 
I've owned many K&B's through the years. They were all .40's or .61's though and usually of older vintages. They all also had Perry style carbs on them and several were "pumpers". I still have several of each including a reverse rotation version I have planned to put in a pusher so I can use a regular prop.
I also like OS engines as they do seem to tune slightly easier. Not too thrilled with Evolution motors, which, by the way, are a different brand than Evo's. Many people don't seem to want to pay attention to that fact.
http://www.evo-engines.com/ are good engines I've heard.

buzzard bait 07-01-2010 06:34 PM

RE: K&B engines
 
The one that's been tempting me is the .61 Twister. Shares parts with the old .61, but different head and porting. At 18 oz with muffler, it is only an ounce more than most 46s, but it swings big props. I see nothing but good reports on it.

Jim

pmw 07-01-2010 07:03 PM

RE: K&B engines
 
Jim,

If you're refering to the .61 with the gold twist on head, I've got one. I've had it for years and it's one of the best engines I've ever had (been doing this for 50+ years; got lot's of engines). I was very careful with the break in and followed the instructions exactly. Mine has the long "tuned" exhaust, but I don't know if it really adds much to the performance. You're right, it's light and is a screamer. Easy to tune and easy to start. I think you'll like it.

Paul

buzzard bait 07-01-2010 07:48 PM

RE: K&B engines
 
Thanks Paul, how noisy is it with the tuned exhaust, if you can make a general comparison with other glow engines? The thing that's held me back is that I'm partial to the sound of four-strokes, but some 2-cycle engines sound fine too. Oddly enough, I really like the sound of my old ASP .91, but that has a Pitts muffler, which may account for the different sound.

Jim

cfircav8r 07-01-2010 09:43 PM

RE: K&B engines
 
I still have an old (20 years) .61 K&B with a perry carb. It has great power and starts with a snap of the spinner, with perfect idle and never stutters or stalls. The stock carb worked fine after fixing the low end air bleed screw, it was a square end screw making it more of an on/off adjustment. After rounding it off to a slight taper it worked fine, however the perry still works better. It is still my favorite sport engine.

pmw 07-02-2010 05:35 PM

RE: K&B engines
 
Jim,

The tuned muffler has no baffling, but the sound is not very loud. Sounds like a welll muffled 2-stroke. Does not sound like a 4-stroke.

Paul

fix-n-fly 07-02-2010 05:50 PM

RE: K&B engines
 
I had a K&B .40 back in the 80's for a Great Planes PT-40. We could get the engine to run on the ground, but about a minute or less into the flight, it would die. Tried everything and had a person that was good at tuning engines helping. I've seen people that swear by them and told me that I needed to heat the engine in the oven and do this and that and something else and then they would be a good engine. Frankly, I need something that will start and work in the limited time I have to fly. Switched to OS max (the FP and LA series) and now Thunder Tiger and never regretted it.

buzzard bait 07-02-2010 07:07 PM

RE: K&B engines
 
Thanks for the response, Paul. A well-muffled two-stroke is OK with me, especially swinging a big prop, which I understand this will do. There is also a Bisson Pitts muffler with the right screw spacing for the K&B .61, and I'd expect that to have a nice sound. I've read such positive reviews, and not a single complaint about it.

Jim

sportrider_fz6 07-02-2010 08:04 PM

RE: K&B engines
 
I have a K&B .65 sportster in a SSE. it has been one of my most reliable engines. it starts easy, wot 2 flips with the carb covered, set throttle to idle connect igniter and 1 flip of the prop it's running. it's been the same since it was new. I'd compair it to a hot .46 motor (not for rpm's) it will turn a slightly bigger prop stronger then a .46

jeffie8696 07-03-2010 12:27 AM

RE: K&B engines
 
Ialways found the Sportster carbs to be easy to tune. Isold my .45 and regret it.

bruce88123 07-03-2010 07:06 AM

RE: K&B engines
 


ORIGINAL: fix-n-fly

I had a K&B .40 back in the 80's for a Great Planes PT-40. We could get the engine to run on the ground, but about a minute or less into the flight, it would die. Tried everything and had a person that was good at tuning engines helping. I've seen people that swear by them and told me that I needed to heat the engine in the oven and do this and that and something else and then they would be a good engine. Frankly, I need something that will start and work in the limited time I have to fly. Switched to OS max (the FP and LA series) and now Thunder Tiger and never regretted it.
The .40 had a ring and was very particular about tuning which made the Perry carb so nice as it tuned easily. IF you run a .40 lean it will quit (or worse). A .40 with a Perry carb and pump (rare on the .40's) was a very good combo. Most didn't want the extra cost or the room the pump took. This is the pump on the rear of the engine case and NOT the newer separate pumps. I'll be using a pumped .61 in my pusher as the tank will be well over a foot away.

freakingfast 07-03-2010 10:15 AM

RE: K&B engines
 
The K&B .48 ABC (Screamin' .48) engine is a great engine as long as you let it do what it's name implies......scream. I is not an engine that will lug a big prop, so prop it so it will turn at 15000 rpm in flight, that's where it makes it's power. It will last a long,long time if you run fuel with castor as part of it's oil package. Learn how to change out bearings when it needs it and it will be a long time servant.

sandyrod 05-17-2011 08:04 PM

RE: K&B engines
 
I own several k&bs and consider them one of the best. I have a 40, a 61 gold head, and an aero 100. They are easy to tune and dead on reliable. The 100 starts on the first flip every time. I have the 61 on a twist 40 and it has unlimited vertical and no dead sticks. I cannot understand why they are not more popular. I own tt, evolution, and os and consider these superior to the tt and evolution and on par with the os. I also had a sportser that was outstanding until i drilled a post with it. Too bad that if tower hobbies or hobby people does not carry something it is not well distributed. With the internet that should not matter. Just my opinion.

buzzard bait 05-18-2011 04:00 AM

RE: K&B engines
 
I picked up a Sportster .20 NIB and I must say, when I first turned it over it gave me a moment of doubt. There was very little compression and it turned like it was filled with molasses.

Out on the test stand with 22% oil half castor and 10% nitro, I used the electric starter because it was so sluggish. Short runs rich, with leaning out briefly before shutting down and cooling. A few cycles, and what do you know?...it's got compression and isn't so sluggish! It just got better and better, and soon it was an easy hand starter. Holds compression beautifully at TDC. First time I felt a sense of accomplishment from an engine break-in.

After beginning with a 9x4, I moved up to a 10x4. Eventually I tried an 11x4 and that went fine, so tried one short run with a 12x4. It hummed along happy as a clam. I love this engine now. Just picked up a .28 NIB too.

Stock carb works fine by the way

Jim

Sport_Pilot 05-18-2011 04:48 AM

RE: K&B engines
 


ORIGINAL: JohnBuckner

You have to be careful when talking about K&amp;B engines as the variety and modifacations over the years has been hugh and there was a time back when that you could go to any field and see almost nothing else.

So having said that I am going to address the .48ABC Screaming Fortyeight. This engine along with the Screwhead Sixtyones were the last ditch effort by the original family owned company to compete with the imports around fourteen years ago.

I feel both were failures and the company was finally closed down in Lake Havasu Az. It was bought by Randy L. of RJL who seems to have sold mostly existing stock of these two engines and there may have been some new production runs.

I purchased two of the .48's and two of the Screwhead .61's when the first hit the stores.
The Screwheads had a totally new porting senario and they were superbly powerful for a while and I completly enjoyed flying turnaround pattern with them. That is untill both at around ten hours blew the complete top of the engine off at the crankcase.

The forty eights were a completly new design unlike the Screwheads with modified liteweight crankcases and their major problem is they shared the old rather crude carbs used by all K&amp;B's.

These carbs all relied on the rotating spray bar for midrange control and in my opinion they just never got it quite right. I originally purchased those Screaming 48's to use on a twin but after first running them that I did not care to use them in that kind of application. In the years since they have served yeoman duty in variety of airplanes and currently are back in the boxs, holding not much interest for me.

Now if you want a truly spectacular engine with superb throttling and all around performance then try one of the new AX line like the 55 for example.


John

All just an honest opinion as a past user of those engines.




I can't speak for the screwhead .60 nor the .48 but I don't see how you can call the carb crude. This is the same type of carb used by OS in many SF and heli engines, and does a surpurb job. Especially the latest one with detents on the idle disk to prevent it from rotating with vibration. The earlyier ones worked well but you had to replace the o rings when they lost friction. The only drawback is that the adjustment is sensitive. The carb also may have poor midrange when not using the nitro and oil percentage they were designed for, but that is true for many twin needle carbs as well. Never had a problem with the two examples I have owned.Excluding the time I dropped a screw driver that went straight down the carb throat, bending the spraybar.

JohnBuckner 05-18-2011 07:09 AM

RE: K&B engines
 
Sport Pilot nothing has changed since I wrote that a year and A half ago to change my opinion and yes I still feel that carburation was the weakest part of the K&B line and toward the end may have contributed to the failure of the screwhead 61 and .48 in the marketplace.

Actually agine in my opinion I feel the best carbs they ever used that were in house K&B and were the first one's with the large smooth block shape with no fins. These worked quite well but these were never used with any of the sportster series.

First problem with the rotating spraybar has to do with education of the customer in how to operate it this at a time when all the competition was going double needle. Heck this was always a big perception problem with the dykes ringed versions of the forty and sixty one's , with folks thinking their engines were no good not realizing that their was almost no compression when not running and the dykes rings relied upon the combustion gasses to complete the seal.

I also feel the machine work on the carbs of the sportster series went downhill and barrel binding was a problem with only slight contamination at a time this did not seem to affect contemperarys to the same degree.

I have had many K&B's the old forty and sixties and a pot load of the Sportsters in all the sizes, In fact My little personal best Cross country flight was with a .45 Sportster lifting the airplane and fifty ounces of fuel.

So yes I am sorry but I still feel the carbs were just a little crude for their time and a contributor to the demise of the company At Lake Havasu before RJL picked up the pieces.


John






All times are GMT -8. The time now is 07:34 PM.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.