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Old October 28th, 2019, 12:35 AM   #2
Mauricemonge
ninjette.org member
 
Name: Maurice
Location: San Francisco
Join Date: Sep 2018

Motorcycle(s): bastardized ninja 250 (think land speed record with a sidecar) soon to swap a 500 engine

Posts: 34
Bogging down and dying kinda sounds like a fuel issue.

Is it wet at all where you ride? Sometimes water (even from a puddle) can get sucked up into the fuel tank vent tube if it hangs low. When this happens, instead of letting air into your tank, it tries to pull water, and basically stops fuel from flowing into your carbs. Opening the gas tank and having it restart right away would be a sign of this. Mine did this several time in the rain, once on a very busy bridge from SF to Oakland in a downpour. One of the more scary things that has happened to me. If this is the case, just trim the line up 6”

Also check your gas tank vent holes for dirt or anything else that’ll plug them. And that the vent line or lines if you have a CA bike, are not pinched off.

Riding with an open gas cap and not having issues would point to any of the above potential issues. Don’t do this with a full tank of gas though

Another very slim possibility would be tight valves. Where the engine at operating temp doesn’t have valves that seal all the way when the clearances tighten up with heat. But that’s something that appears closer to 5-10min of running. Are you running harder/hotter on your way home?

Check your vacuum line to your petcock, make sure it’s soft and has a good seal, and pulls good vacuum while running.

*edit, threads showed up with a similar problem:
Is your igniter overheating? Someone poured cold water on it and it started right up. Maybe try that next time? The bogging seems less like no spark though

Last futzed with by Mauricemonge; October 28th, 2019 at 12:47 AM. Reason: More stuffs to add
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