Carb Question

tribonnie

tribonnie

Full member
Location
uk
I am stripping the cards from 1977 Jota
Do these diaphragms look ok, is the wrinkling a sign of failure
Thanks Richard
 

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I am not a fan of removing them. Had a bike here where the pumps weren't working properly, ran like shit. Accelerating needed a lot of sensible opening of the throttle. Maybe it was this bike only, but it only ran well again, after we fiitted new pump diaphragms and made sure, the valve at the top is working properly so that gas comes into the pump.

I would completely overhaul the carbs with a serious cleaning in an ultrasonic, heated bath tube, replace all jets, needles, gaskets, o-rings etc. and make sure they run well... Trying to safe money will lead to spending even more...
 
probably cheaper from Ducati Paddy, and he can easily handle the complete overhaul as well, (unlike Eurocarb)
MT 1200TS has not had them for 35+ years, and she can run with the best, WOT or through the cogs, to disable, I remove the plastic bell crank from the carb body tops, but be carefull, the pins come out only one way, if you press them out the wrong way, the tiny alloy towers will break off, this is not an issue at all unless you want to re-install them at a later date, racers that remove them, strip the entire caboodle which then shows externally, I prefer the "filled in" look.

If you are visiting a dyno house (I have used three in recent years) they all told me/asked me to be sure the accellerator pumps were disabled, screws their readings and makes the process much longer and involved, with always some doubt, ie did they squirt or not?
CLEM
 
Can't speak for triples but I noticed zero loss of throttle response when i tossed them. I also initially just removed the plastic lever mechanism but then took off the housing and fitted a little alloy plate using the gasket and plunger part only. I don't care if I can't whack the throttle open at idle and have the motor whiz immediately to redline from idle - have no interest in that. Or cracking open the fully throttle suddenly from 2000rpm.
 
I'm with the no-pumps guys. Deactivated them like Clem described.
I don't feel any loss in performance, not even when accelerating.
Instead approx. 1 ltr. less per 100km. But I'm talking bout 750s.
Don't know how the triples react.
I always replace the needles and the spray nozzles, as they are prone
to mechanical wear.
After an ultrasonic cleaning jets should be ok.

Ernesto
 
Not sure how petrol prices are going up around the world, but here in the UK they are skyrocketing. Reason enough to disconnect them pumps and use a slower throttle hand šŸ˜€

But seriously, I'm a pump disabled believer. Having them connected helps occasionally, sure, but the trouble is they are working all the time, even when their effect is not required.
 
Haggis said:
but the trouble is they are working all the time, even when their effect is not required.
Click to expand...
They're not working all the time, only from about half throttle to wide open (exact point depends where your ramps are set to activate). If you're just tootling around at civilised speeds you're unlikely to pump heaps of fuel through.

I didn't try de-activating the pumps when I had Dellortos on my triple, although I was tempted to, just to lighten the throttle action. Now that I have Mikunis the action is lighter anyway.
 
The top octane rated fuel here in Sydney has cracked $2oz a litre, the highest price ever. As usual, some SUIT toddled out on TV and started wanking on about the oil price in Singapore. Just imagine buying a litre of milk on Monday for a $1 and on Wednesday its price had doubled to $2 and on Friday it was back to the original $1. All from the original truck delivery on the previous Sunday. That's the complete BS that SUIT sells. I have a Bridge that I also want to sell. BTW that fluctuation gets added to Business costs for EVERYTHING.
 
Ordered new plus rebuild kit to dismantle and clean. Seems to be difference of opinion on priming the pumps but will clean our non return valves and hope for the best. thanks Richard
 
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