229f running troubleshooting

karl johnson

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hi all, and can i have a little assistance please.
i have searched the forum and cant find anything similar.


i am having 229f set up issues on my comet. i.e uneven running then spitting through bellmouth at idle then cut out and die... indicating weak.
the carb i bought new from burlen and jetted.


the running at the min is accelaration is very good. exhaust snuffling or popping on over-run. and the snap is ok no spitting.

with engine hot if i was to open pilot 1 turn it will fight to keep running i.e spit spit spit. and is pretty much like that until closed all the way.. using throttle stop to acheive even running cannot be done at the min.. i am not experienced with pre monoblock. but single monoblock on a twin i am ok ..tuning etc . can anyone tell me where the hot spots for air leaks . or maybe they are all like that???? what do you think.. :confused:
 

Len Matthews

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It could be that the tiny drillings in the jet block are obstructed. Aerosol carb cleaner may help but if not the jet block will have to be removed and the drillings cleared with very fine wire.
 

greg brillus

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I have had several issues with the new 229/289 carbs, and always lean running. I generally go from a number 4 slide to a 3 1/2 cutaway. One carb I had problems where the idle mixture screw was completely ineffective, and I could only keep it running either with the choke slide fully down, or else placing my fingers over the bell mouth to restrict the airflow and therefore enrichening the mixture. I gave up to the point of completely stripping the carb right to the bare jet block. When I looked carefully at the seat area where the mixture needle goes, I could see about 1/3rd of the seat was missing, and what I thought to be either a casting flaw or a misalignment in the machining process. I reassembled the carb and returned to Burlens, explaining in a detailed letter what I had found. They had the carb for about 3 months, and finally when I called, they explained that nothing was wrong, and after testing they returned the carb to me.....I refitted the carb, after I installed a 3 1/2 slide, and it tuned up ok. So to this day I do not know what they did if anything to it. But I think this could be a similar issue to what you describe...It may be worth sending it back and tell them what problems you are having.....Cheers......Greg.
 

Magnetoman

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hi all, and can i have a little assistance please.
It would help if you could provide some more details. Why did you put a new carburetor on it? Was it running fine before this? The reason more information is needed is the symptoms you describe easily could be caused by ignition problems so tearing into the carburetor may be looking in the wrong place entirely.
 

karl johnson

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hi i bought the bike just over a year ago. and it was fitted with a monoblock carb.i did breifly ride the bike with it on even that carb i did seem to have the same trouble spitting and cutting out at idle. and that pilot screw was turned all the way in hence i thought carb trouble at that time. i did strip the monoblock and i thought ive seen better. i decided on 2 things then... 1 buy a new 229f which was the carb i wanted on it anyway....2 because i am going to ride this bike i am going to send it away for an engine strip check repair any issues and build also set the bike up(with 229f on it) i sent it to a vincent chap i wont mention his name. magneto was not overhauled as the spark is good. i have got the bike back 5 months later, with a report that it runs and rides well which is true. it starts no problem. runs brill. its just tick over. thats it so far.
 

greg brillus

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The only other issue I would have suggested is that perhaps a leak from the inlet manifold. But if it has been rebuilt then this is unlikely. Most new 276 carbs I have fitted have been trouble free, but I can't say the same for the 229/289 carbs.....not sure why, as the carbs are basically the same.....although they are most likely made in small numbers, but I have always found them to run lean off idle, so I modify the slides myself by taking 30 thou off the bottom. This makes the slide more like a 3 1/2 which seems to make the engine run fine. The specs of the new carbs are as per original, but our modern fuels are not, so some allowances need to be made to offset this, I think.....Anyway, good luck....Greg.
 

karl johnson

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cheers for that greg. ive not long finnished putting it back together ive poked through all the passageways in the block and ive run the manifolod across an oil stone lightly.. it started second kick so ille try to tune it tomorrow, fingers crossed
 
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