# 1985 720 with Z24; bogs down repeatedly



## cchao (Sep 10, 2012)

Hi,
I just bought this truck and recently noticed that it bogs down momentarily when trying to accelerate out of the hole, but picks back up and is fine otherwise. 

When I was checking out the carb, I pulled on the throttle just a little bit. The engine revs as you apply throttle and then bogs down, then picks back up. If you go past this point by giving it more gas, it runs (but shakes a bit periodically). However, if you give it just the right amount of gas the engine maintains rpms (about 1100 rpm, I don't have a tach) for about a second or two, then bogs down, then you can hear a click like a spark, then the motor revs back up like nothing happened. Then it repeats this process indefinitely. 

I'm pretty sure the carb is working well enough and I think it's an ignition problem because of the click noise right before it picks back up. Anyone have an issue like this? Thanks!

Charlie


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## zack. (Nov 19, 2009)

Not sure if this is it, but the electrical connectors for the carburetor are known to break a wire due to how tight they are and all the vibrations from driving. I would try asking over @ 720world..


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## CMax03 (Jan 17, 2009)

Carb is full of thrash in fuel bowl....Fuel lines maybe coming apart on the inside and clogging up your main jet when you start flowing fuel!


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## CMax03 (Jan 17, 2009)

Also check that both Intake and exhaust Ignition coils are working properly! Intake stays on continuously, exhaust is ON during part throttle acceleration...OFF during decel and WOT!


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## cchao (Sep 10, 2012)

Yeah, it's the primary barrel. It sputters, especially at low rpms. I'm thinking about getting a weber carb cause I don't really feel like rebuilding this one. Thanks for the response!


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## smj999smj (Jan 1, 2006)

Those Hitachi carbs aren't that bad to rebuild if you take your time and it's a whole cheaper for a rebuild kit than a new Weber. Regardless of which path you choice, I would install a new filter (or filters...I remember some of them 720's had two: a regular fuel filter and a an electric fuel pump filter in the back) and pump some gas into a clear, glass jar before connecting the line to the rebuilt or new carb. This will allow you to make sure there are no contaminants in the fuel that will trash up your new carb.


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## cchao (Sep 10, 2012)

Yeah, I just don't have the space to do the rebuild. I've changed the fuel filter in the rear next to the fuel tank. I don't see anywhere else on the line that there could be another filter before it hits the carb. Definitely don't want to trash a new carb with dirty fuel.


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