Author Topic: CB400F exhaust port question  (Read 629 times)

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Offline Claude

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CB400F exhaust port question
« on: February 24, 2021, 01:48:36 PM »
Is the ridge shown a the picture part of the exhaust port or is it an old gasket?
I tried to remove it but I failed. If this an old gasket, is there a special trick to remove it?
Thanks!

« Last Edit: February 24, 2021, 02:50:36 PM by Claude »

Offline zxshep

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Re: CB400F exhaust port question
« Reply #1 on: February 24, 2021, 01:58:41 PM »
Hi, Claude.  I believe that's the old gasket.  Mine looked similar and I thought there were no gaskets on any of the four ports with mine.  I ended up taking a pick and finding a lip and was able to pull it out.  After getting the first one, the other three were easy because I had technique.

They are wedged in there pretty good, but I didn't need pliers, just the pick and a decent tug and then worked my way around until it popped out.

Hope this helps.
2005 CR125R
1975 CB400F

Offline evinrude7

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Re: CB400F exhaust port question
« Reply #2 on: February 24, 2021, 02:48:26 PM »
+1 on the pick
cb750 k6 - ugly

Offline Claude

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Re: CB400F exhaust port question
« Reply #3 on: February 24, 2021, 02:52:28 PM »
It’s with a pick that I tried to remove it. But I stopped because I was only scratching the aluminum port and the gasket was only laughing at me...

Offline bryanj

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Re: CB400F exhaust port question
« Reply #4 on: February 24, 2021, 03:06:09 PM »
Big screwdriver
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline Claude

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Re: CB400F exhaust port question
« Reply #5 on: February 24, 2021, 03:15:09 PM »
Big screwdriver
Great! I’ll try this tomorrow.

Thanks for all the inputs guys !!

Offline hawaiikid

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Re: CB400F exhaust port question
« Reply #6 on: February 24, 2021, 07:07:13 PM »
I believe the old gaskets were copper and can be wedged in there pretty tight.  just be carefull with the fins as they can break off very easily.

Offline claudio.fauni

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Re: CB400F exhaust port question
« Reply #7 on: February 25, 2021, 12:28:01 PM »
Cut with a dremel

Inviato dal mio SM-A750FN utilizzando Tapatalk


Offline Bodi

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Re: CB400F exhaust port question
« Reply #8 on: February 25, 2021, 04:07:14 PM »
I wouldn't want to be poking in there with a dremel.
Scrape the face with a screwdriver or something to confirm it is a gasket - gaskets will not be silvery head alloy. Most are copper, really old ones have metal (thin steel?) folded over asbestos cord.
Tapping straight in with a slot screwdriver has loosened them for me, once loose you can get a pick underneath.

Offline Bodi

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Re: CB400F exhaust port question
« Reply #9 on: February 25, 2021, 04:38:08 PM »
exhaust port with no gasket