HD8'S

[daily]

long time no howdy,
was out in the perfect weather yesterday [75+] after a run down the coast,pulled pots-pistons out of my HD8'S [for no good reason] and obsereved fuel seemingly percolating[deliberate cadence] from the rear jet. might this indicate a faulty needle valve??? "CONSTANCE" has been lightin up a little lazy when warm [smell fuel]
i've installed grose jets in the past.
with respect 59er

 

[Bob_Spidell]

If the 'cadence' was in sync with the fuel pump pumping then, yes, you probably have a stuck or defective needle valve/Grose jet.

 

[Patrick67BJ8]

long time no howdy,
was out in the perfect weather yesterday [75+] after a run down the coast,pulled pots-pistons out of my HD8'S [for no good reason] and obsereved fuel seemingly percolating[deliberate cadence] from the rear jet. might this indicate a faulty needle valve??? "CONSTANCE" has been lightin up a little lazy when warm [smell fuel]
i've installed grose jets in the past.
with respect 59er

Sounds like it could be a cracked diaphram on the jet.
Patrick

 

[daily]

again,for no immediate reason
went to get rebuild parts [HD8'S] from moss [local]
was told they get thier jets [.125] from joe cuerto.
while observing the jet tube [where the needle travels]
i can see what appears to be an unfinished riffeled surface in this conical bore. probably step drilled ???
there are distinct ridge rings at interivals the legenth of the jet tube. is this the desired profile? can they be polished,otherwise finished???
the rubber glands are suspect also, irregular casting
the brass od on jet stems was scuffed & scratched on several.
what to believe,moss says they have multipal sources for these???
with respect 59er

 

[RF Thom]

Don't cheap out with Moss or VB carb parts, get the OEM parts from Joe. I learned this the hard way. I was ordering a bunch of parts from Moss and included some jet/diaphragms. Installed them and my car wouldn't idle or run correctly, the carbs wouldn't even respond to adjustment. Took them apart several times, checking needle setting, blockages etc - everything seemed OK, no better. Then I started to examine the individual components comparing them to the ones I had removed. The new jets were a composite construction [as you note] with the hole too large and they were 0.025" too short. I decided to order new parts from Joe - installed them, tuned the carbs, and the car idles fine and runs great.
Regards, Bob