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Old 05-15-2023, 04:13 PM   #5
Desuboi941   Desuboi941 is offline
 
Join Date: Apr 2023
Posts: 32
Quote:
Originally Posted by Texas Pete View Post
Preface: This is all on an OEM factory carb.


Don't have a hawk but all the times my idle is running really rough and then every few cycles wants to quit and die but the momentum in the fly wheel keeps it going again is always been on my bike due to a vacuum leak and a lean condition causing that behavior. This also when quite bad will show up as lean popping well into the throttle/main and trying to get it to idle will run a bit then hesitate on a cycle and die. My culprit most of the time is the choke because my bike's carburetor has a choke cable and it screws down against the carb body using a crush washer. When I'm doing lots of tuning and taking the carb in and out frequently every once in a while I will finger tighten the choke cable and then work on installing the slide and fuel hose and everything else and forget to come back and wrench tighten the choke cable crushing the washer. Over time the vibrations back my cable out until air leaks into the choke circuit in the carb and creates a bad lean condition. If I didn't have that then having a bad seal on the engine side of the carb allowing an air leak would have done similar. To date I have never had it be the jets that have done behavior as you described with my non hawk bike. The air/fuel adjustment screw being set for the previous pilot jet I removed and went to different size usually manifests itself as hesitation just off idle and onto adding in the main jet tube circuit but everything above and below that runs fine. When I take the bike around the streets and beat the snot out of it to bring it up to full temperature and then set the idle between 500-1000 wherever it is just about to die and then do my air/fuel adjustment routine and dial it in I usually dial that behavior out. If I couldn't then I'd look at moving a size in jetting.


But bottom line is if you have removed and reinstalled the carburetor you need to check everything that is supposed to be sealed either with rubbers and clamps or crush washers or whatever is sealed and that includes the exhaust side of the equation. Only then can you start to work on tuning your settings and dialing things in. And if the bike rides decently well after you put it all back together but then like ass the next time you ride it suspect vibration has loosened something somewhere related to the above during that first ride.
Thanks for all of that, I’ll definitely check everything, I did just reinstall my exhaust with a new Crush gasket, and the exhaust flange wouldn’t tighten down all the way but there doesn’t appear to be any leaks. It’s probably on the intake side, probable between the head and intake manifold. Hopefully adjusting my valves clears a little bit of the vibrations up.


 
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