Author Topic: The elusive surge  (Read 4432 times)

Offline Alexrayz

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Re: The elusive surge
« Reply #30 on: January 19, 2022, 08:46:37 AM »
Hey K2 (is that your droid name?)

Nah man by all means labour away! Having taken some time off and re read Bryanj's post, I did not in fact follow that procedure to the letter. I will take it back from the top.

Two things I have forgotten to mention: I do not have the spring retainer for the air filter and I haven't got either the air filter cover. I have used duct tape as a makeshift cover but no garantee it is air tight. Do you think these missing elements might leanen the mixture? I say this knowing that at the moment the mixture is rich ( sooty plugs) but if it does leanen the mix it wouldn't  help getting a reliable setup right?
Lastly on that front: The airbox is the original and because of its age, it has warped a bit, the front end is a tad concave. Consequently connecting properly the air intakes for carb 2 and 3 is not feasable. I can get them in and even tighten the collars but not get the connectors all the way in. I guess that doesn't help either? Could not find a lot of info on those issues.

All the best
If it aint broken don't fix it

Offline Bryanj

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Re: The elusive surge
« Reply #31 on: January 19, 2022, 10:51:19 AM »
If you have covered the top with tape no air can get in! Use half a clothes peg to pushthe filter forward and leave the top open totest

Online McCabe-Thiele (Ted)

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Re: The elusive surge
« Reply #32 on: January 19, 2022, 11:05:23 AM »
When I ran my engine for the first time after 12 years prior to the current rebuild I had great difficulty with fitting the four air box connections - it's such a tight space and difficult to connect them.

When rebuilding the bike I found that with no rear mudguard, wheel, or filter housing  the whole lot can be fitted much easier and you can get the pipes to fit fully & clamp them in place. That said it's a lot of work to just get the darn pipes fitting into the carb intakes - just mentioned it out of interest.

Trying to think outside the box:-

Just a thought are all your compressions good & even could this variation be due to changes in compressions as the engine starts to warm up?


Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html

Offline taysidedragon

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Re: The elusive surge
« Reply #33 on: January 19, 2022, 11:48:59 AM »
Alex, the best way to get the airbox rubbers to fit onto the centre carbs is to remove the air filter element from the   air filter box, remove the connector tube and rubber to give you as much access room as possible.
Then use a screwdriver handle or a piece of wood with a rounded end to push the airbox rubbers forward onto the carb stubs from inside. Your hand has to manoeuvre down into the air filter box and partly through the large opening in the front.

It's difficult,  frustrating and even painful at times, but it's possible.
Gareth

1977 CB400F
1965 T100SS

Offline allankelly1

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Re: The elusive surge
« Reply #34 on: January 19, 2022, 11:54:02 AM »
Hey K2 (is that your droid name?)

Nah man by all means labour away! Having taken some time off and re read Bryanj's post, I did not in fact follow that procedure to the letter. I will take it back from the top.

Two things I have forgotten to mention: I do not have the spring retainer for the air filter and I haven't got either the air filter cover. I have used duct tape as a makeshift cover but no garantee it is air tight. Do you think these missing elements might leanen the mixture? I say this knowing that at the moment the mixture is rich ( sooty plugs) but if it does leanen the mix it wouldn't  help getting a reliable setup right?
Lastly on that front: The airbox is the original and because of its age, it has warped a bit, the front end is a tad concave. Consequently connecting properly the air intakes for carb 2 and 3 is not feasable. I can get them in and even tighten the collars but not get the connectors all the way in. I guess that doesn't help either? Could not find a lot of info on those issues.

All the best
Hi Alex

Here is the picture of the filter retaining



You can get this from David Silvers

Also if you have no filter lid I could 3d print one based on my original



Just let me know

Best wishes Al


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Offline Alexrayz

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Re: The elusive surge
« Reply #35 on: January 19, 2022, 12:05:18 PM »
Hey Alan,

That would be great indeed, I'll see that with you by PM! I was thinking of making a sudo retainer with a wire coathanger, just something to hold the filter snug.
If it aint broken don't fix it

Offline allankelly1

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Re: The elusive surge
« Reply #36 on: January 19, 2022, 12:19:58 PM »
Hey Alan,

That would be great indeed, I'll see that with you by PM! I was thinking of making a sudo retainer with a wire coathanger, just something to hold the filter snug.
Yes coat hanger would work

Also modelled your air box lid now




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Offline Alexrayz

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Re: The elusive surge
« Reply #37 on: January 19, 2022, 12:53:47 PM »
Thanks Alan!
If it aint broken don't fix it

Offline allankelly1

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Re: The elusive surge
« Reply #38 on: January 19, 2022, 01:11:57 PM »
If you have covered the top with tape no air can get in! Use half a clothes peg to pushthe filter forward and leave the top open totest
Solid lid or duct tape is ok as there snorkel at the back of the filter housing




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Offline Alexrayz

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Re: The elusive surge
« Reply #39 on: January 19, 2022, 01:31:36 PM »
Alex, the best way to get the airbox rubbers to fit onto the centre carbs is to remove the air filter element from the   air filter box, remove the connector tube and rubber to give you as much access room as possible.
Then use a screwdriver handle or a piece of wood with a rounded end to push the airbox rubbers forward onto the carb stubs from inside. Your hand has to manoeuvre down into the air filter box and partly through the large opening in the front.

It's difficult,  frustrating and even painful at times, but it's possible.

I shall suffer then. Sucks to have big hands in those cases. Thanks for the tips!

Gotta say this thread is starting to co;pile quite a bit of info, good for everyone.
If it aint broken don't fix it

Offline allankelly1

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Re: The elusive surge
« Reply #40 on: January 20, 2022, 09:16:49 AM »
Well that a new air box lid for Alex sorted








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Offline taysidedragon

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Re: The elusive surge
« Reply #41 on: January 20, 2022, 03:49:28 PM »
Very nice. 👍 You might get a few requests for more of those. 😁
Gareth

1977 CB400F
1965 T100SS

Online K2-K6

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Re: The elusive surge
« Reply #42 on: January 20, 2022, 04:36:15 PM »
Very nice work there Alan.

Offline allankelly1

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Re: The elusive surge
« Reply #43 on: January 20, 2022, 04:37:16 PM »
Very nice work there Alan.
Thank you


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Offline Dave

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Re: The elusive surge
« Reply #44 on: January 20, 2022, 05:01:24 PM »
Excellent work!

 

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