Engine hesitates and/or stalls

[richard17]

I’ve been riding a 1993 ST1100 for six months now. It’s a great bike, but I sometimes experience—unpredictably—the following problem: the engine starts to hesitate and sometimes even cuts out completely. Sometimes it’s just a momentary hesitation, and after a minute I can ride on normally at full power. At other times, I manage to get it running normally again by using the choke (followed by revving it hard in neutral). Last week, the issue occurred after 200 kilometers of trouble-free highway riding.
It seems to be related to the fuel supply. I was about to dismantle, inspect, and clean the fuel system—including the carburetors—but then I came across the topic regarding the emergency bypass of the fuel valve, so I’m going to try that first.
Do you happen to have any other tips regarding possible causes and solutions?
Thanks in advance for sharing your knowledge.
Greetings from the Netherlands.

 

[Erdoc48]

Many will chime in here- check your vacuum valve first and foremost- bypass it (instructions on here and easy to do)- if that fixes it, you can leave it as is, get a repair kit for the valve, or get a new valve (I think they’re still available). If it was running well, it’s much less likely clogged jets. Clearing them requires pulling the carbs which is a bigger job. If it’s not the valve, you can run some fuel system cleaner in the tank to clean everything. Also, these bikes are old so I’m sure a new fuel filter wouldn’t hurt. If the above doesn’t help, it may be a failing fuel pump.

 

[Uncle Phil]

Bypass the valve and toss it - just my experience of over 1/2 million miles on ST1100s ...
Could be the fuel pump failing - when they do, they can be very erratic.
They'll be fine, then fail, then restart ...
Next place would be looking at the carbs.