No, 7000rpm prob is still there

My mechanic mate came round the other day, he took it for a spin and reckons there was a fuel delivery problem.
When we took the tank off, we noticed that fuel would flow always.
He decided that we should disconnect the vacuum line from the tap and plug it up with a screw, it had no effect, problem still there but bike ran for nearly 100k's.
The other day, it sort of died, like no fuel. Reconnected the vacuum and the bike stared up again (2 or 3 go's).

I’m thinking that my fuel tap/vacuum switch got stuck on and just only now, has fixed itself.
The vacuum mod made no improvement to the 7,000k prob.
I did notice some fuel smell in the last month (before we messed with it), maybe due to the vacuum switch not switch off and I never turn the fuel off on the bike.
I still think I might have a mis-configured vacuum line setup, as I only have one line going from the back of the engine to the tap.

I'm assuming that the tap switch is some sort of vacuum ball stop, but I could be playing with myself.

 

The tap switch has a vacuum arrangement in it, which only allows fuel to flow from the tank to the carbs when the motor's running, but you must have a vacuum line on the tap going somewhere - carbs should be where to look. It sounds like the tap unit is dirty - remove, clean and service may be the way to go.....[X(]

 

Hi

Just a question, was the bike running OK before or has it always had the 7k rpm problem?

The reason I ask is, I just brought a 89 and it felt flat above 6k (still pulled but not like a thou should, only just kept up with a mate on a R1100 BM).

So i pulled the bottoms of the carbs (bit dirty) but the interesting part was up top.

The rubber diaphrams for the vacuum slides had been incorrectly installed and had no seal on 2 carbs. Ran lean on 2 carbs at high rpm but started fine.

hope this may be some help, Greg

 

Nice one, Greg !
Good to see a new member throw his hat into the ring !

 

You mean the top of the rubber diaphrams? (the lip that fits into the groove)?

I plan to pull the tops and I'm going to dump some carbie clenner down them (after removing the sliders)

I have remove the tops before and noticed nothing bad, but I will be re-looking,
thanks gregcbr.