Evening all I think I may have a problem with said pump/gas squirters on my FCR39s. Firstly the bike's wheelyness has been lacking and secondly cold starting does not seem to be being helped along by a couple of twist grip twists. I've just had a look at the mechanism in action and the plunger plunges very slowly. As you'll know the plunger is pushed down by a spring loaded wheel, rather than the actual slide lifting bar. I'm wondering if it's supposed to be so lethargic. I've not had a chance to pop the carbs off the bike and give the slide lifter a tweek to see if the things squirt. Anyone know if you should be able to see said squirting with carbs in place but air filter removed? I also suspect that one or both of the mixture screws may have shifted as it all feels and sounds a bit out of balance at gentle loads and revs. I've tried to check 'em in place but have failed due to my less than impressive screwdriver selection ..... only stubby I've got is a posidrive. Has anyons had these screws move on their own? Cheers chaps Grunt
I have a Suzuki DRZsm for a bit of a hack, I know your thinking what's that got to do with your FCR.....But I fitted an FCR39mx carb to it. The acc pump is actuated by a rod that presses down onto a diaphragm which creates the 'squirt'. These diaphragms are prone to splitting allowing the fuel back past them rather than into the Venturi. I replaced mine as part of the reconditioning of the carb before I fitted it, it was about 20 quid iirc. Oh and I can see the squirt through my air box.....using a boroscope. Oh R&D make a thing called a flexjet....which might make your adjustments easier....but they are difficult to buy in the UK.
The plunger moves slowly on mine too but you can easily see the fuel squirting down the carb if you look down the intake, you can also smell if it's going in. When I had mine off for adjustment a while back, I drained out the fuel first but when I opened the slide the accelerator pump shot a jet of fuel 8ft across the workshop...
Good job you weren't smoking at the time. They are nearly as good as a super-soaker for range and flow, guess that's why my Monster is only getting low 30's MPG...
