Author Topic: Worn carbs on CB750 K1  (Read 612 times)

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Offline Rolycat

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Worn carbs on CB750 K1
« on: April 14, 2017, 12:18:26 PM »
Hi,

I'm new to the forum and wanted to share my findings. The attached photo shows the inside of a Jet holder p/n 16139-300-004 after 52k miles of use. From the severe wear noted I have good confidence that this is likely cause of my overly rich condition at low and mid range RPM. The same wear pattern continues down into the jet holder and is particularly bad around the cross holes. Interestingly enough the needle doesn't show corresponding wear (I can still make out the turning marks). Of course the needles may have been replaced by the past owner but I doubt it otherwise he would have fixed the worn brakes, worn swing arm, leaky forks seals and loose steering stem....all in dire need of attention

I thought this photo would be good information for all those that wondered about carb wear

I have new jet holders on the way!

Cheers

Offline ekpent

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Re: Worn carbs on CB750 K1
« Reply #1 on: April 14, 2017, 04:19:33 PM »
  In the picture it looks like it may have had a bad case of corrosion. Any sign of corrosion inside the carb bodies ? Water getting in there and sitting at one time can do some damage.

Offline Rolycat

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Re: Worn carbs on CB750 K1
« Reply #2 on: April 15, 2017, 07:31:59 AM »
Hi,
I know what you mean, but I don't think so as its an Arizona bike and came to me completely rust free and original. The other jet holders are not quite so bad but show the same wear pattern, including  a wavy pattern like sand on the beach.
I'm looking forward to see if new replacements fix the problem. I'll update the forum