Monoblock Float Wear

Not sure if others have found this but have been getting my long unused ES2 (thanks Covid) ready for a run next weekend.
Fuel tap on and fuel came gushing, strip the carb and clean all up and quite a change - it gushed much faster the next time.
A closer look and the float needle has worn a divet in the float face, enough for it to hang up and not seat the needle.
New float and instant fix.

Happened to my Atlas Monobloc float. I think it is a common occurrence that goes un-noticed by many tuners.
Slick

ntst8 said:

Not sure if others have found this but have been getting my long unused ES2 (thanks Covid) ready for a run next weekend.
Fuel tap on and fuel came gushing, strip the carb and clean all up and quite a change - it gushed much faster the next time.
A closer look and the float needle has worn a divet in the float face, enough for it to hang up and not seat the needle.
New float and instant fix.

Click to expand...

I am in the process of putting a 1966 Triumph T100 back on the road after many years of very heavy neglect. I have reached the point where it runs but I cannot stop the OEM Monobloc float needle from sticking. The carb will be fine at rest. The float needle will seat but once running the vibrations will cause it to overflow. Then it runs rough, smokes and dies. I too noticed the small divot in the float face. I have been wondering if this divot is not my problem. Rather than replace the float I have sanded and then polished out the divot. It seems to seat but the true test will be when I have it running. If not I will order a new float. It may be that this one is just too heavy.

It worked. I used a small flat file to dress the float face until the divot was gone. Then I used Q-tips, cut in half, covered with a mild abrasive car polish and turned by my drill motor to polish the ramp until it had a mirror finish. Then I did the same for the inside of the seat It leaked once at first but that was it. It didn't leak while running.

Big_Jim59 said:

It worked. I used a small flat file to dress the float face until the divot was gone. Then I used Q-tips, cut in half, covered with a mild abrasive car polish and turned by my drill motor to polish the ramp until it had a mirror finish. Then I did the same for the inside of the seat It leaked once at first but that was it. It didn't leak while running.

Click to expand...

One more thing: My monobloc was not running at idle and it was showing signes of running very rich. My also carb showed signes of significant corrosion. It was suggested to me that the pilot jet was not seating properly and was allowing fuel to bypass the jet. I gave the carb a vinegar bath and amazingly it did a number on the corrosion scale and buildup. This is more than I ever expected. Then I took a soft stick from a Q-tip (I cut off the tip) and using a dab of very mild car polish I ran it around the pilot jet seat. Then I blasted it out with carb cleaner. I then screwed in the pilot jet with a bit of red marker on the tapered seat. The seat came out showing full engagement all the way around.

I assembled the carb, after the vinegar bath, and it behaved quite differently. Tickle it and it bangs right off (I did adjust the timing slightly as indicated by my tests) so I am pretty happy about that. It will only wanted to run if I continue to press the tickle button periodically.

I let is sit for a while in disgust and then about 15 minutes later I gave it a second try. this time it ran longer. I increased the slide height and it ran at idle. I turned the air/mixture screw until it would take gas without hesitation. I have some more tuning to do but I am making progress.