LD 150 Mark 3 fuel flow

[Fairburn]

Thank you for input I just wish I had swooped condensor when I had flywheel off. The flywheel was remagnetised by scooter surgery so that should be sound.
This week I will remove condensor is there a good internet source for a new one.
Thank you also re fuel flow reassurance will transfer attention to electrics. One final point on the differing needles jets etc found on the standard LD carb is that I sent for a 255B atomiser again nos and it had a different depth to part that you slot socket/spanner. I have photos. Atomiser is otherwise same length , size and number of holes. I have used this but cannot see how it could cause an issue unless someone knows different?
The jet no 72 and D1 needle were on a 1957 LD 150 that I bought recently. Incidentally it had a LDA frame.

[sunrisemac]

Condenser seems likely, can the float needle move up or down in the float in your carb and is it possible to check the fuel flow through the float needle jet?

[Fairburn]

Sunrisemac-Float is not punctured and is seated correctly at top and bottom. Should therefore float smoothly. Could remove top of carb and measure flow easily into filter bowl area. Not sure how to check flow after this point into float area as top would need to be in place.

[Fairburn]

image.jpg

Two identically numbered atomisers but different shapes

[sunrisemac]

Sunrisemac-Float is not punctured and is seated correctly at top and bottom. Should therefore float smoothly. Could remove top of carb and measure flow easily into filter bowl area. Not sure how to check flow after this point into float area as top would need to be in place.

I am unfamiliar with your carb, (I deal more with old race cars), but wondered if the float could have been moved down the float needle which would shut off fuel flow via the needle valve earlier which in turn would then give a lower level of fuel available to the jets. It still might be worth a quick check to make sure the fuel pours through the needle valve at a good rate to fill the float chamber, although condenser would still be my first bet.

I have occasionally encountered a strange thing (although only on the odd occasion) with my solid mounted carb in that at sustained high revs the fuel 'froths' and then gives an incorrect mixture for a short time until I change the revs and allow the float level to recover.

Hope you find the problem and get it sorted

[Fairburn]

Finally tracked down the problem. The coil. This must have been deteriorating gradually. Had obtained a spare coil and checked readings against it. With a multimeter across two small connectors (Primary circuit) and multimeter on 200 ohms both gave reading of 2.2. Then checked on same multimeter setting between any small connector and centre pin ie outlet to spark plug. The coils were the early triangular type. I got no reading on faulty coil and on the second one a reading of 16.22. Bingo.
The scooter now is all it promised to be with new coil fitted.
One thing worth mentioning is that a set of after market points looked as if horizontal nut and bolt holding spring arm looked very close if not earthing out on bolt holding down grounded side of points. I checked length of spring arm on points and it was 0.5 cms shorter than original set. This could well have reduced efficiency of action. Cleaned up original points and clearance of two bolts looked better.
Thank you everyone who nudged me in the right direction and to ' You Tube' where I did a quick course on multimeters.