Hi, I’m new to the club and have yet to meet anyone else with a Monza to make a comparison. The bike has a slight hesitation when leaving a corner having shut the throttle right down. It seems to be the transfer from idle to the next stage of the carb. One manual tells me to put the needle 2 notches from top and that is with a 48 idle jet, the other says 3 and that is with 50 jet. My needle is at 2 from the top but not sure which jet is fitted. Any advice on this please. Once past this little glitch it runs fine. New needles and main jets recently fitted. Carbs have been balanced with a carbtune and it has a steady tickover.
Many thanks
Ken
I think that bike is pretty much the same as a mk III V50. Are you running on points? What grade plugs and how old are they?
From my experience with a twin-points Monza (1982), getting everything very well set up is worthwhile. Sounds like you have done the carbs, but what about the ignition? I found that it was very difficult to get both points gaps and timing correct for left and right within the available adjustments but by a bit of trading one against the other I could at least get both sides the same.
Did carb balancing include both idle position and response to throttle opening?
If you want to know the jet sizes, they are stamped on them, although rather small writing and may need any fuel residue cleaning off so they are legible.
Are you on standard air filter? Anything else might warrant a bit of trial and error with needles/jets.
Ian
Hi, thanks for the suggestions. The bike was originally running on Ngk BP8ES and l changed to Ngk BP7ES about 1500 miles ago and it made a big improvement for town riding. When removing the plugs they are a respectable colour. At present it is using points and I agree they are quite tiresome to set up accurately but l did persevere. Having found an article in the forum about someone with a Monza changing to the Dyna S and it making a big difference I’m going to try that. The carbs were synchronised both for idle and when opening the throttle and the two columns remained very even. If the Dyna solves the problem that will be great, otherwise l think I’ll have to pursue carburettor settings which will be very much trial and error and time consuming. Thanks once again for your interest.
For carburettor jets and needles, the genuine stuff can start to add up if you’re working through options, but there are “knock-off” versions available. I set up a PHBL24 on my little Ducati from scratch. A set of 10 various needles from eBay was about the same as 1 genuine needle. You can also find the needle profiles on-line quite easily which helps with deciding which to try next.
Couldn’t find any atomisers so had to get those from Eurocarb.