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1974 T500 Running Rich/Weak?

Posted: Sat Jun 17, 2017 11:37 pm
by BlackBearT500
Hi,

I have a 10,XXX-mile 1974 T500 that has brand new MIJ points/condensers, freshly rebuilt vacuum petcock, new Mikuni viton-tipped float needles and seats, new air filter, new NGK plugs, very fresh carbs. It has had everything ignition and carb-related adjusted to factory specs.
My problem is no matter if the bike is hot or cold, it bogs and has essentially no power when trying to take off (it feels like I'm
trying to accelerate a ragged-out moped) so I have to rev the hell out of it to get going...and then it just seems to be lacking some power all-around the ranges compared to my last T500...it seems as if I'm pushing it too hard for any type of riding.

I have taken the plugs out, checked and cleaned, both after short 10 minute rides and a 100-mile ride, and they are always a little wet, but tan/clean (never black/sooty, but always slightly fuel saturated). The plug checks always yield the same for both cylinders, so the issue must be equally affecting both cylinders.

Have any ideas on this? Why's it running rich and being so difficult to get going? It's riding season and I'd love to figure this out. Any bit of help would be greatly appreciated!!!

Thanks in Advance,

Trenton

Re: 1974 T500 Running Rich/Weak?

Posted: Sun Jun 18, 2017 6:06 am
by fredvincent
Trenton, have you checked the exhaust and baffles are clean inside? These can clog up with carbon and make it feel like it has no power.
Good luck.

Re: 1974 T500 Running Rich/Weak?

Posted: Thu Jun 22, 2017 1:30 pm
by BlackBearT500
Yes, I have checked the exhaust baffles/chambers and the headers are NOS and were just installed according to the P.O. It just has a ridiculous off-idle bog and the plugs are always clean yet slightly saturated with fuel.

A thing to mention is the bike revs and runs very well off-idle when the choke is engaged and feels as if it has plenty of take-off power...very snappy. It's almost like it is lean off-idle without the choke engaged, causing the bog, but what I don't understand is why the plugs are saturated with fuel.

Could this mean my pilot circuit is not functioning correctly (lean condition)? But throughout the rest of the RPM range my overall carb setup is rich?

Thanks Again,

Trenton