hunting an spluttering

[afk40]

Guys. ma 89 alp, just bought it, when ye open it up, it feels like its not getting the full power, it kinda feels like it has more to give.. especially when yer at around its 80mph mark, it wont go faster, but it keeps hunting kinda thing an ye kin feel it wants to do more being the trustworthy aul bike that it is,

the guy whom a bought it fae says he just got the carbs all done, but its spluttering , also he said the fuel petcock needs a diaframh as its on reserve all the time, an ave noticed the wee pipe that goes tae the cylynder on the left side is blanked off should that be going to the petcock.??? if it draws or pushes air thru that for it to work properly am not reall mechy minded, but as it is its blanked off an he says the petrol is just now on gravity feed rather than air assisted. would that be right sayin that.?

also ma front brake a think could be much better, an the rear practically doesnt work. it has 42k on it, it rides fine other than that, ye have tae keep the throttle wide open all the time fur it tae perform, but a think this is due tae it splutterin or hunting as they say... any ideas.???? tae a remedy.. thaks,, afk

[StumpyFingers]

First thing is to replace the fuel tap diaphragm and the vacuum feed pipe.
Also replace the spark plugs and check the HT leads.
If the diaphragm has split then it would have the pipe removed from the carb to stop the fuel from entering the carb continuously. You may also have dirt in the fuel line stopping the fuel flow.

[afk40]

stumpy, thanks fur that... yes the wee pipe thats comming out of the cylynder is blanked off, i ve noticed its had new plugs, how much an where can i get a new diaphram ??? do you think this might be the cause fur it not gettin full power. also ave noticed it doesnt come alive till above 6k revs, an when a say alive a mean it feels like its comming in to a power band of sorts a know 4 strokes havent got a powerband, but it feels like is wanting tae go, but cant because of the hunting kinda thing...thans. afk

[StumpyFingers]

The Hunting could be a reg/rec failing or a coil. If it has intermittent power it could be losing energy before it gets a spark.
I would check the low tension wires for a break. plus the HT leads. Hopefully they are OK else you will need a new coil.

[FatFergie]

I think wemoto do a repair kit for the tap as does DaveSilver.

[afk40]

ave got one in hand , but now am thinkin o selling the bike