T3 not pulling

My brother in law has my T3 Cali on long term loan. I only get to see the bike once or twice a year. Last time, a couple of weeks ago I took it for a spin. It had been sat for many weeks and started easily and after a couple of minutes warming up ticked over perfectly. Pulls away nicely up to about 4000 then starts struggling. The higher the gear the worse it is. In 5th it won’t go over 3500. My first thought was blocked main jets but the carb has been recently cleaned.Second thought was advance retard problems.A mate said it’s dirty points.My reason for asking is that I will get down to see it in the next week or two but will only have half an hour so would like to go pre armed with a solution!Do I do the carbs or the points?Or something else?In an ideal world I would rather have a weekend to “play” and work it out myself but… Any suggestions?

Stuck choke?

good reply. The choke appears to shut off ok after starting but maybe that little rubber seal isn’t sealing properly…

I use the hand chokes rather than cable as I have had that problem before.
Black spark plug is a clue.

My check list would be:-

Pull plugs n check colour
Pop thumb over each cyl to check compression
BUT if it IS starting and running this should be good

Check choke is working and sealed
Check carbs JUST cos they been cleaned ONCE is NO guarrantee the jets are clean the crud in modern fuel will cause fuelling problems.

ONLY if that is all good check the timing via the 'Ole and then check points

Agree. My Convert suffers from this if it gets left for any length of time. It only started to suffer when ethanol was added to fuel.

I have freed the brass plungers more than once by taking them out rubbing them with one of those green scrubby things used in the kitchen and lubing by wiping with good old vaseline I also use the scrubby on the inside of the carb tube they go into it cleans off the gunge without abrasing the brass or alloy.guzzibear2012-11-20 20:00:42

When I had this problem on Cheryl’s T3C, it turned out the needles were in the wrong slot (should be second from top?)- but I assume your bike was running OK last time…unless they were put back incorrectly after cleaning?

some ideas: cracked or unseated carb rubbers, blocked tank vent, partially blocked fuel line or fuel filter

Condenser’s failing?

Check spark plug colour if black head straight to the choke plungers and you will find one or both are stuck in there bore/s. It’s a common problem. Do what guzzi bear says and clean them and the bore with a kitchen scotchbrite pad.Chuck pad in bin afterwards and when better half asks where it is deniy know anything about it.