Author Topic: help with 400  (Read 2017 times)

Offline rwgoldsmith

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help with 400
« on: June 02, 2012, 08:49:50 PM »
i have a 91 400 that i have been trying to resurrect. i rode it for a year then she left me stranded and i got too busy to fix it. any rate it turned out that my battery shorted out and the o rings in the carbs were toast. I got her to run great for a while and now suddenly she barely runs at all. when i can get her running she immediately surges to 3500-4000 and very slowly will go down to a normal idle if i fiddle with the idle adjustment. then if i hit the throttle she surges again and again very slowly will go down to idle.
Any thoughts,
Thanks
RW

Offline andrewsw

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Re: help with 400
« Reply #1 on: June 03, 2012, 12:22:49 PM »
Things to check:

1. Throttle cable -- this is a probability, IMO, based on your description. Make sure it's not getting hung up. It must fully return when you let go of the throttle.

2. make sure you have *no* vacuum leaks around the intake.

Did you replace the o-rings? Did you fully clean the carbs? and if so, did you make sure everything was properly adjusted and returned to stock (I assume) settings?

A

Offline rwgoldsmith

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Re: help with 400
« Reply #2 on: June 03, 2012, 05:55:52 PM »
well on a hunch i checked spark and while i get spark on all 4 all are really weak. this being said only 2 spark plugs work. i swapped plugs around to check. i checked the coils and they are both reading about 13-14k ohms. it appears that the service manual and it wants 30-50k is there anything i should check before i order new ones.

throttle cable fully returns
did the spray check to test vacuum
carbs are at stock settings

Thanks
RW