interchangeable fuel tanks

[billdn]

Are the CB 350 & 400 fuel tanks interchangeable? Reason for asking is that I have a second hand tank which is I believe for a 400/4. However after selling it the buyer contacted me to say it wouldn't fit his frame. Having sorted him I collected the tank from him, and as soon as I got home offered it up to my 400/4- and he's right 😒. Is it possibly a 350 tank ,it's about 10mm too narrow where it would locate on the rubbers below the headstock and snags the main frame tube. The tank doesn't appear bent or damaged so that it would have been compressed, any ideas?

[Nurse Julie]

The 350 and 400 have totally different size / shape tanks.

[SteveD CB500K0]

Post a photo.

I'm sure someone on here will be able to ID it

Steve

[billdn]

Quick search on t'internet for  350/4 pics shows it's definitely not a 350 tank. i'll take and post some pics

[Orcade-Ian]

Hi,
I have both 350 and 400 fours and I seem to remember once fitting the 350 tank on the 400 just to see if they would fit.  I also tried the side panels.  It was a long time ago but I don’t remember changing or removing the rubbers and I have had a glass of wine since then.
I have a refinished 350/4 tank up in the workshop and I’m on with another 400/4 at the moment so if you can hang on till tomorrow, I’ll check and report back - unless someone else can do it more quickly.

Ian

[billdn]

Cheers Ian

[AshimotoK0]

http://www.sohc.co.uk/index.php/topic,8130.msg53334.html#msg53334

[AshimotoK0]

http://www.sohc.co.uk/index.php/topic,8438.msg56293.html#msg56293

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[Orcade-Ian]

Thanks Ash,
I think the front section of the frames are identical and pretty much of the rear end too, except for the rear footrest area - I’ll still check tomorrow for future ref.

Ian

[kevski]

http://www.sohc.co.uk/index.php/topic,8438.msg56293.html#msg56293

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That just doesn't look right.

[Orcade-Ian]

It’s just as I thought, the distance across the rubber buffers on the frame is the same on 350 and 400 fours.

I bunged the spare black 400 tank on the 400 I’m on with (and it fits🙈) and followed up with the spare 350 tank with no extra effort.

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I realise it won’t help the o/p but might be useful for others building specials.

Ian

[billdn]

Thanks Ian, I've no idea what I've got then! it's not a 350 tank for sure - nothing like it. but it's so like a 400/4 apart from it won't fit at the one point ! Puzzled of Sussex 

[Orcade-Ian]

Do you have the pics yet?  There’s bound to be someone here who knows what you have, unless yours has been modded in some way.

Ian

[Menno]

Please post a pic. I am sure we can determin hat kind of tank you have without any problem..

[billdn]

Well it was cold in the workshop but i battled the elements to take some pictures. i have titled the pictures "Query" and "Correct" for clarity. Much closer scrutiny would indicate that at some stage the query tank has had a "knock" or similar as there appears to be a crease around the head-stock area which could have somehow forced the sides together, not much but sufficient to reduce the clearance, also the lugs are slightly out of level on the query tank but only slightly. i suppose i could strip the tank to see if there is wadges of filler to establish the "Knock" theory - do you reckon it could be "persuaded" out slightly or is it a scrapper,shame because inside it's quite good.