Inline filters with octopus?

[johnstewart]

When I swapped tanks a few weeks ago, I *had* inline filters and tried to install them... but I have the original octopus vacuum/fuel thing, and wanted to keep it in place. And I couldn't get the big filters (they're a cone type) installed without kinking the original fuel lines.

So, inadvisably, I left them off, and now I fear my carbs are junked up. Thought I got a tank of bad gas, but after I burned it off, it's still kinda boggy at low throttle (I think this means what, idle jets clogged?).

Anyway, does anyone have a recommendation on how you can install inline filters without chopping up hose? Do I just need to shorten the original fuel lines which connect to the petcocks? Hate to do that; I like the bike as stock as possible.

[jetmechmarty]

What I did was use two Visu-Filter in line fuel filters. They go just above the tees between the number one and two carburetor, and three and four carburetor. I used Motion Pro Premium Fuel Line that I believe is tygon. Whatever it is, it's very pliable and lasts a good while. I plumbed the left carburetors to the right petcock and the right carburetors to the left petcock. It gives me more room for maintenance like carb sync and tank removal and installation. It's stock enough for me.

[NorCoaster]

I did exactly what Marty did and it worked like a dream. You're just asking for a break down by leaving the octy on

[johnstewart]

Thanks gents.

NorCoaster - I read Marty's post to mean he left the octopus on, but just swapped the sides to have more room with the hoses. Now your post left me confused. =)

So you took the octo out completely? Doesn't that leave vacuum hoses (or the nipples on the petcocks) to also seal up somehow?

I frankly have no idea what the vaccuum is for. What do we lose by taking out octo?

[bikerphil]

I frankly have no idea what the vaccuum is for. What do we lose by taking out octo?

The vacuum is applied to the octy fuel shutoff valve to open the valve and let fuel flow to the carbs ONLY when the engine is running. When the engine is shut off, the vacuum is lost in which closes the octy to prevent fuel from leaking out of the carbs in the case one of their floats gets stuck or a float valve becomes faulty. If you remove the octy, you should turn the fuel taps to 'off' after riding to prevent a fuel leak if a carb float/valve problem develops.

[johnstewart]

OK I thought this was the general idea... but when I have my tank off, and set the petcocks to On, the gas flows even without vacuum being applied. Shouldn't that only work on Prime?

Or maybe it'll flow regardless of nothing is hooked up to the vacuum nipple?

[bikerphil]

OK I thought this was the general idea... but when I have my tank off, and set the petcocks to On, the gas flows even without vacuum being applied. Shouldn't that only work on Prime?

Or maybe it'll flow regardless of nothing is hooked up to the vacuum nipple?

'On' position flows gas to the octy then on to the carbs (as long as the engine is running), prime bypasses the octy and flows gas directly to the carbs weather engine is running or not. 'Off' is off, no gas flowing from the taps. Gas will flow from the taps in every position with the exception of off.

[jetmechmarty]

Thanks gents.

NorCoaster - I read Marty's post to mean he left the octopus on, but just swapped the sides to have more room with the hoses. Now your post left me confused. =)

So you took the octo out completely? Doesn't that leave vacuum hoses (or the nipples on the petcocks) to also seal up somehow?

I frankly have no idea what the vacuum is for. What do we lose by taking out octo?

That's right. I still have my vacuum shutoff (octopus) installed. Those things usually fail open. I never heard of one failed closed. They should be rebuilt after 30+ years neglect or all bets are off. If it actually works as advertised then leave it alone.

It's a safety device. Take it off and you lose automatic fuel shutoff in an accident.

[NorCoaster]

There's also a thread in the modifications side of the forum if you want to see exactly how it's done. I capped the vacuum nipples on the petcocks by tapping them out with an M6-1.0, put some baby panhead machine screws with PTFE paste in, and voila! Also be sure to cap all the other vacuum nipples...but you can use regular old rubber on them since there's no chance of fuel eating through them.

[dpotter58]

I did exactly what Marty did and it worked like a dream. You're just asking for a break down by leaving the octy on

I have had a half dozen or so Specials, left the octy on each an never had one cause a problem.