Hi from Athens Greece,
I have owned my F2 for about 2 years now.
The bike was sitting for more than a year in a basement before i got it. From the beginning i had the same problem.
When cold, the bike runs smooth, but after a getting warm in traffic it runs not smooth at all at low rpms. I cant start smoothly from stop, it jerks and when the rpms go up it clears for a while.
I took the bike for carb cleaning twice, but nothing happened, the problem is still there.
I told the mechanic that the problem is only when its hot and he is "looking into it" for about 10 days now...
Any ideas?
New sparks, air filter, etc

Thanks in advance guys

 

Check out these links, The regulator/rectifier (R/R) is a flaw that seems to crop up quite frequently on the whole series. Being an electrical issue, it can manifest in strange ways. Stumbles being one of them.


Charging System Diagnostics - Rectifier/Regulator Upgrade - Triumph Forum: Triumph Rat Motorcycle Forums

https://cbrforum.com/forum/f2-tech-9...-solved-27739/

Hope this helps, Ern

 

^^^your avatar creeps me the smurf out....

I'd replace the plugs, check for vac leaks as well. Coldness, all your pos dry rotted rubber constricts and works fine, warmness, all your pos dry rotted rubber expands and leaks. Then look at yo air filter, if its all dirty your choking your bike. for example, lets say i bet you to run a marathon, and you say okay, then i tie a rope around your neck and say run bish!!! you aint going to far hahaha

 

Motorcycle oil in the crankcase, not automotive? Wrong oil could cause clutch slip once the engine gets heat in it.

Is the motor revving normally, but the bike is difficult to get rolling, or acts like it doesn't want to go when you get on the throttle, but the engine is running otherwise fine?

 

The oil is quality brand semisynthetic motorcycle oil, brand new plugs, new air filter.
The engine revs fine, just stumbles for a while when i leave the cluch lever and some times i hear a 'blob.." sound in my tank and after that the rpms go up normaly until the next gear change. It seems to me like a carb fault, but why this doesnt occure with a cold motor?
Thanks for the advice so far

 

check the vent & overflow lines comingout of the tank - they shouldn't be plugged up - they should free flow.

A glugging sound in the tank almost sounds like the tank is acting like the bottles on an office watercooler - as you siphon fluid out of them, it is putting vacuum on the tank until it finally sucks some air in - then it is able to flow more fuel until it repeats itself.

although - if this is happening on each susccessive shift - then it's something else - your carb bowls should hold enough fuel to get you a mile or more before being refilled.

Wonder if you might be hearing fuel being spit back through the carbs into the airbox or something.

 

Got the bike back from the shop yesterday and it was running as good as if it was elecric!
The mechanic told me that he did a good carb cleaning and he noticed that the previous mechanic did not fit the carbs correctly and some air could get through...!
I will see how it runs in traffic when hot and i will come back.

 

If your bike if still acting up, it could be your ignition coils. when electrical systems go bad often times they will work when cold, and start doing crazy things when they get warm. So as your bike warms up you might start losing spark. And if it's only one of your coils, it would only affect two cylinders, and possibly only one. which could cause the bike to stutter