750 f1 fuel leak

[Skoti]

Not sure what's causing this but when I park up in my garage for a couple of weeks or more and then pull the bike off the centre stand I get a few drips of petrol onto the garage floor from the carb overflow hoses.

Anyone had the same issue?


Carb float levels were set at 26mm about 4 years ago and not touched since.

I was maybe thinking about worn needle valves, but would this be a normal CB750 fault?
Bike has done 48,000 miles on originals.


regards

Skoti







 



 

[Bryanj]

You should be turning the tap off when you park it

[Skoti]

Forgot to mention the tap is turned off.

[Bryanj]

That would suggest the tap is leaking through, could be bad washers under the screws holding it onto tank

[hairygit]

That would suggest the tap is leaking through, could be bad washers under the screws holding it onto tank

The F1 tap is held on by the large gland nut Bryan rather than the internal screws of the pre K5 series of tanks. Sadly these taps when worn or getting old do leak past the tap packing, but it is not available as a spare. A new tap is the only real cure, and they are crazy expensive compared to the earlier K series taps

Sent from my POT-LX1 using Tapatalk

[Spitfire]

Hope it's not the same as my F1, turned out my leak was caused by pin hole leaks on the bottom of the tank by the petrol tap, hence my bike has an F2 tank.

Cheers

Dennis

[Skoti]

Thanks for the replies.

The petrol tap seems ok, but maybe it gradually seeps fuel over a couple of weeks or so?
It's a spring loaded cone type tap and does not have the usual rubber packing washer with the holes.

I'm also thinking of renewing the needle valves and seats, but not sure about the quality of the aftermarket replacements available.

[blackeagles]

while you have the bowl off you need to check the brass pipe inside the bowl for any split

[Skoti]

Last night I rigged up a plastic pipe and bottle connected to the fuel tap to check for seepage overnight and this morning I have maybe a tablespoon of petrol in the bottle.

So before I go and fork out the best part of 80 quid for new fuel tap is there a way to repair those cone type taps fitted to later K and F1 models?

thanks in  advance

Skoti

[hairygit]

I've known a few people have a go at repairing them, BUT the tap cover plate is riveted on, and no internal parts or packing was ever sold separately by Honda. Only the filter sick and large rubber washer that seals the tank to tap join, and they are very pricey for what they are.

Sent from my POT-LX1 using Tapatalk

[Skoti]

Hi,

thanks for the reply.

The on/off/reserve tap plate is held on with two 4mm screws under which is an '0' ring and a wave washer.
There's a drilled alloy tapered cone valve held into the tap housing with a strong spring.

Google part number 16011-341-004 and you'll see the tap in question.

I'm looking at ebay at the moment for taps in Germany as DS has no stock.

[Skoti]

Sorry I gave the wrong part number!

Instead, google part number 16950-341-671 for the fuel tap.

[Spitfire]

Just googled that part number and Wemoto came up with one for £28
https://www.wemoto.com/parts/picture/ry-16950-341-671

Cheers

Dennis

[Skoti]

Thanks Dennis,

but normally I prefer genuine Honda or oem parts if possible as reliability and safety are important for me.

Managed to find a fuel tap in Germany and needle valves in USA, not cheap but you know where you are with genuine Honda stuff (hopefully).   

[Skoti]

Eventually managed to get the stuff needed to complete the job, hopefully good to go now.

Here's the pics:-

https://photos.app.goo.gl/2MNER31C6ET2Dz2W8


Thanks for all the help and suggestions.


Regards

Skoti