Brison 2.4 problems
 

My Brison 2.4 has never tuned well, always has run well on the ground but on roll out for take off it starts to miss and pop. Land it and it runs well again. I have cleaned out the jets and carb and it is doing the same thing still. Just wondering if maybe I should go to the bigger gas lines through out the system?? Anyone else had the problem and what was the fix??

RE: Brison 2.4 problems
 

I do not have such an engine, but I do know engines pretty well. It sounds like it is leaning out, either intermittently or evenly during T/O roll. Therefore, there are two factors involved: 1. Vibration, and 2. Airspeed. Try running the model and then holding it inverted. If it starts misfiring again, then you probably have a loose fuel line fitting or a cracked fuel line that allows air entry when it is shaken. Take a look at the carb position and see if there is the possibility of an air pressure change or restriction. Next, if the RPM increases significantly during takeoff roll, it may be that a fuel line restriction is causing the problem, either because of overall small flow capacity, or some other restriction. The only way I can think of to check that is to ground run it with a prop of less pitch or diameter to run at a higher RPM to see if that induces the misfire. If it does, then an increased fuel flow is required. Be sure and check all the fittings, including the needle and main jet for foreign objects. I hope this will be helpful.

'Jet-Eye' Don

RE: Brison 2.4 problems
 

I'm sure you do not bigger fuel lines. These things just sip gas ( I have one ). I did have the same problem with another brand of engine and tracked it down to the battery. It would supply enough voltage when running static but as soon as the prop unloaded it started backfiring & missing. I was running an 1100 mah nimh and switched to a 1400 mah nicad - end of problem. This may or maynot help.

RE: Brison 2.4 problems
 

Hey Don,thats a great piece of advice,i'll try it on my 2.4 also! Right now the only cure i've found is to use a 17/6 zinger prop and really let her turn up the rev's. Got that info on the 17/6 use from Bubba Spivey, Mr Lanier himself!

RE: Brison 2.4 problems
 

Good Lord man a 17 - 6 [X(] Mine turns an MSC 18 -10 @ 8000 some guys are running 20 - 10.

RE: Brison 2.4 problems
 

Thanks guys. I have tried different sizes of props at different RPMs so that wasn't it. I have the 1700 amp NIM and they call for A NI-CAD so there could be something going on there?? I had already gone through the carb. I will go through the gas tank one more time and check all the lines and make sure the gas isn't foaming. I want to check the ignition pick up and make sure that isn't loose and just for grins I will change the battery over to A NI-CAD. I'm also going to pull the needels and roll the engine over and try to flush out the carb just in case I missed something??
I'm open to any other ideas that haven't been brought up. This is getting to be A pain in the mule.

RE: Brison 2.4 problems
 

If you get disgusted I'm looking for another one :D Mine gave me a lot of grief at first but I sorted it out and now it's like the Energizer Bunny. On & on & on.

Actually I sorted mine out by sending it to C & H Ignitions. They replaced the ignition module and told me that Brison should never have installed the sensor that far away from the magnet. They made a new bracket and moved it closer . That was 5 years ago and it hasn't missed a beat since.

RE: Brison 2.4 problems
 

GUYS
i have the b2.4 for some time now.
i had them both..the old verstion with the MECH ADV IGI, and the new one with the FIX pickup sensor.

both had problems!

1. prop: the minimum size is 20x8!!!!!!!!!!!!!! and this is by the manufacturer him self GARRY.
2. set is an issue, needs a lot of time...for myself and other guys more exprienced than me!
3. chk the fule system-> tank, make sure the tube is not twisted-> holes in fuel line-> for some reason the B2.4 dont like a "T" line for fueling???->try to add a ventury knob to the carb, like the ones that come on the Zenoah's...u can get one from BONZI

moreover, when this engine is tunedup and working..it is pure fun:D but it take time to get there.

enjoy

RE: Brison 2.4 problems
 

To each his own but I've had a "T" fitting on my 2.4 for years and never a problem. Just replace the fuel if it gets too brittle.

RE: Brison 2.4 problems
 

lucky guy:D

RE: Brison 2.4 problems
 

HOORAYYYYYYYYY thank you don! the battery change did the trick! My 2.4 is swinging a 20/8 at 7600rpm! I LOVE IT!!!!!!!!!!!!!!!

RE: Brison 2.4 problems
 

abacro, What brand 20/8 prop are you getting 7600rpm with?

RE: Brison 2.4 problems
 

Well I finally was right about something. Maybe 2007 is going to be a good year :D

RE: Brison 2.4 problems
 

I turned that with an APC 20x8 propeller.

RE: Brison 2.4 problems
 

My 2.4 was a PITA to start yesterday, thought I had flooded it. Finally get it running and the transition seems a tad sluggish so I leaned the low needle a hair. (Just got it back from a full service - was thinking that needles might need a mild tweak to compensate for the difference in locales.) I have 3 flights on it since the service with no issues. Once in the air the engine was pulling my 15lb CG Yak like always - nice strong performance on a 20 x 8 Xoar prop. I flew for 6-8 mins and all was fine, good throttle response coming out of downlines and all. Then I put it into an inverted flatspin and about 3 rotations in the engine bogs. I roll out and fly wings level for a bit and the engine finally cleaned up (after 15-25 seconds). I come around to land and it won't idle down low enough to land, so I go around and drop my throttle trim several clicks (5-6). I put the yak on the ground and then the engine is just about dying the idle comes down so low, and has trouble coming back up to taxi in to the pits.

Next flight I fire the engine up - it hits on the 5th flip without having to re-choke, and seems to transition decently on the ground. High end is nice, so I taxi out, blow the motor out and get it into the air - full throttle climb out, and as soon as I get about 15 degrees nose-up, the engine drops RPM again on me, but thankfully is still pulling the plane well enough to avoid a stall. I circle and land it, and the engine dies on rollout when I try advancing the throttle.

I'm thinking that my LSN was lean to begin with, and I made a mistake by leaning it more. Cool 45 degree day (dense air) probably wasn't helping any. I'm going to richen it up a bit and do a lot of ground testing this week see how it runs. Also planning on going through all of my fuel tubing/clunks. Will also pull the cover off the diaphragm and check it for any cracks/tears/pinholes. Anything I'm missing?

RE: Brison 2.4 problems
 

Last night was the first time I had A chance to look at it. I found the pick up was loose enough to slide it back and forth and it was sitting about half way over the magnet?? I set that and tightened and will double check the timing sometime today then go through the fuel system. It took some effort to slide the pick up so it isn't like it was bouncing around or anything.
Here is A question for you guys. Why when I get an engine that was test run and all set up from the dealer, I got this one from Garry direct but I have bought from others like RC Showcase, I use the same prop and fuel, they never seem to run well. They have all needed tuning. This one has been A problem from day one. Just wondering?

RE: Brison 2.4 problems
 

Not 100% sure what you are meaning, but there are always issues that can make a difference in how an engine runs that are determined by the atmospheric conditions that an engine sees.

If the dealer/manufacturer test runs the engine in a climate controlled room, or even outdoors with very low humidity at 3000 ft ASL, and then ships it to me in Louisiana at 75ft ASL, and I try running the engine at our typical 75% humidity on a 55 degree day - I'm going to expect the engine to respond differently if the needles are set the same. I'm guessing the engine would be running a little lean in my location.

Also the mounting in the cowling can cause some pressure changes that act on the carb differently, and may require some adjustments to make the engine run well in-flight. It's always something.

RE: Brison 2.4 problems
 

After reading your first post I was going to suggest looking for a loose wire but I have a feeling you found the answer in the loose pick up.

All engines require tuning after they are purchased. No engine is tuned for best performance out of the box. Believing so will only create a lot of frustration and irritation when the engine fails to perform to the owners satisfaction. You will always have to tune an engine to the enviornmental conditions and the prop selection.

Use a good synthetic oil and use a mix ratio of 70-1 per Gary's recomendations. All Brison engines used to call for a 70 to 80-1 synthetic mix before the company change.

If you have a CH ignition, the minimum battery you should use would be a 4.8 volt, 800 mAh battery. The type does not matter, but the voltage does. An 1,100 mAh, 4.8 volt battery will last you all day.

RE: Brison 2.4 problems
 

I changed the battery from A 4.8 2700 amp Nim to A 4.8 1400 Ni-Cad just to see if that makes and dif. I also changed out every line in the fuel system then pulled the needels and turned over the engine flushing out the carb. Also opened up the diaphram plate and checked the pump. Added more foam around the ignition. Everything looks good to go so I will fire it up tomorrow and see what happens. Can't fly it yet but hope to get to the field this week and give it another try.

RE: Brison 2.4 problems
 

I haven't read through the thread but a new switch wouldn't hurt matters and is relatively cheap.

RE: Brison 2.4 problems
 

I tried the zinger first and only got 6600,then a menz and got 6900,then finaly a mezlik and hit the 7600. I flew it with all three props,and truth be known i prefer the menz better but the zinger sounded more right. Not having to really winde up the motor to 7600rpms or more to me means it should last alot longer :)

RE: Brison 2.4 problems
 

Just A thought but my engine came without A velosity stack, could air flow over the carb have something to do with my little problem?? Still just shooting in the dark here and trying to cover all the bases.:D

RE: Brison 2.4 problems
 

I have flown mine with and without the velocity stack and found 0 difference. That being said have you tried running a vent line from the diaphram cover on your carb into a "static air" location ?

RE: Brison 2.4 problems
 

Not yet but I was told to give that A try. Solder on A brass tube and run A line into the fuse or out of the air flow. I think I will just go ahead and do it now because we are getting hit by some storms this weekend with high winds and it looks like I'm grounded until mid week or even next weekend. Thanks for the tip.

RE: Brison 2.4 problems
 

Gray Beard is your 2.4 the old style like mine with the mechanical advance or the new style with the Cimmaster ignition ? I am considering a new 2.4 but they now have this type ignition on it and I can't find any pics. or feedback on it.

RE: Brison 2.4 problems
 

I got mine last Dec. and it has the C&H ignition with the white ring holding the pick up. I was told they changed over to one with A black ring and had some problems with it but C&H was changing them for people?? I don't think I'm having an ignition problem and the other ones I have seen like mine were all fine. I'm sure I'm having some sort of fuel/carb problem but I'm leaving no stone unturned at this point.
My only wish on this engine is that the needles were on the side instead of facing the front of the engine. A G-45 is so much easier to tune then this one. I know, I can turn the carb but then the linkage needs to be changed and they have one of the best linkage set ups I have seen on an engine.
I'll get it figured out but I just now have the time to play with it. I was just starting to move here when I finished this plane and never had the time to get it all set up before I left. I had other problems besides the engine but A new RX fixed all of that. :D

RE: Brison 2.4 problems
 

After about one hour a running on 2.4 Brison when I went to full throttle it would start to miss unless I backed off the throttle. It just kept getting worst till I had to take the cowl off and found the white pick-up ring set screw had worked lose and the timming was off. Reset the timming by the degree's wheel and she runs perfect again. All this after I screwed up the carb settings that were ok to start with.

RE: Brison 2.4 problems
 

I found the time setat 35degrees advanced so I moved it back to 28degrees last night. And yes, I did run it and set the needles before checking the time so Iwill be turning screws again. My plan was to fly today and see what happened but the wind is starting to kick up so ground testing is about all I will do today.
I really want to get this plane up and running well so I can get the trim set and start flying.

RE: Brison 2.4 problems
 

Gray Beard keep the chin up you'll get it yet. The timing change may help you.


For those of you who may be interested, this is what the "NEW" Brison 2.4 looks like now. The ignition shown is an ignition noise reduction "UPGRADE" @ $45.00 US. Not sure if this "upgrade" is essential or not. The engine really has a much cleaner look.

RE: Brison 2.4 problems
 

Don, Is there a clamp to help secure the spark plug cap?

RE: Brison 2.4 problems
 

I do not have the engine YET. These pictures were e - mailed to me by Cimmaster in Ontario, Canada who are now manufacturing the Brison & Revolution engines ( that's another story we all know about ). But to answer your question it looks like there is a "spring ring" around the metal boot in order to hold it on. I personally would use a gear clamp just in case.

This ignition upgrade was suggested by Cimmaster in cases where you may have radio interference with the standard type spark plug lead. I like it because there is no ground wire to hook up. I am considering another 2.4 and that is why I got them to e - mail me some pics. The ones on there web site depict the old style mechanical advance. Is the electronic any better ? Who knows. But apparently this is the only way they come now. With all the "cheaper" competition available now I'm not sure how they will fare. They are $450 ( engine & standard ignition ) + $45 ( optional shielded ignition ) + $96 ( Bisson pitts ) = $591.00 + shipping. Pretty expensive for a 40 cc engine [X(]

Are they that much better than the competition ? That's a personal preference I guess.

RE: Brison 2.4 problems
 

Thanks Don and the chin is up and I have high hopes that everything I have done has cured the problem. The one time I got the engine to run right it was really A power house.
That ignition does clean it up but I always liked the looks of mine as it is. It had A better shine under the tree then the rest of the decorations.
I did have A BAD RF problem at first and went through everything and nothing helped. I went to A new PCM RX and problem cured. Move forward in time about 6 months and I was using that old RX to build A crash box and the antenna fell off in my hands!! Glitch found.:D Sometimes when going through everything it should be taken A little farther. :eek: What can I say ?? OOPS!!

RE: Brison 2.4 problems
 

Actually I wish they still had the "old" type ignition and then if I buy another I could interchange things if I need to trouble shoot. Sound familiar ;)

RE: Brison 2.4 problems
 

Trouble shoot?? Me??
Never got to see one with the old advance system.
Too much wind to go out today but I did fire it up. Just A little touch here and there on the needles and it's sounding better then it ever has.
I will post up after I try it out at the field if it runs OK now. Trouble is I have done so many things to it who knows what the fix was. I think it was just out of time and that was the last thing I checked. Still, could have been fuel draw??
I sure want to thank everyone for all the input, it was A big help just knowing I was on the right track.

RE: Brison 2.4 problems
 

I thought yours was the mechanical advance system. It's not like this ?

RE: Brison 2.4 problems
 

I have a Brison 2.4 on a 1/4 scale Taylorcraft and had the same problem as you and found out that it was the airflow into the carburetor. After I installed a velocity stack and experimented on its position I never had the problem again. Hope this helps

RE: Brison 2.4 problems
 

The new type ignition will not provide any better noise prevention than a properly installed odler style. Some may have noticed that CH came out with the shielded plug wire, the same as this newer unit, quite some time back, still using the standard sized spark plugs. However, the new ignition does provide a means for the user to run a smaller CM-6 plug, which is often a bit more difficult for some to obtain. Makes for an easier "in cowl" installation with the shorter plug. Those that have the older CH ignitions can do the same thing by contacting CH to obtain the plug adapter and sending in their old ignition for a plug wire/cap conversion. You probably won't need the external shielding with the CH conversion, though.

I have to admit the the housing for the Hall sensor and the rotated carb body looks pretty good. Other than that, it appears to be the same engine it was before.

RE: Brison 2.4 problems
 

Got it!!!!!! After spending the time tweaking and peaking, changing things the beast started to run better, that's better, not well. I was almost there but it was always just off enough to run rough. Today I put some fuel line over the high speed needle and was able to get my fingers over it and get the traction needed while the engine was running. I leaned it in slowly until I found that sweet spot and it is now back to being A power house.
I'm going to keep flying it set like it is and with my 20X8 Zinger broom stick on it for A couple of gallons then start to switch props and see how well it's going to perform.
Didn't like having my hand that close to the prop but as long as I kept it behind the cowl I was OK. I only had to open the cowl A little to get my fingers in there and it was worth it.
Too bad it didn't come with A carb with the needles on the side and still have that nice linkage!:D

RE: Brison 2.4 problems
 

fyi.... I couldn't get any power out of my brand new 2.4 swinging a 20 x 8 prop. I adjusted the needles and was very disappointed till I ended up cutting the tips off of the bisson side dump muffler. it was like night and day.
steve.