|
|
Post by stirling11 on Dec 24, 2023 17:09:44 GMT 1
I thought I'd solved this issue by giving the bowl an educated tap as fuel was pouring out of the right hand drain tube on the right carby
That has now stopped, however fuel now pours out of the left drain tube on the same carby
The left carby has no such issues
Can anyone suggest a fix, it only happens when the bike is running
Many thanks
Stirling
|
|
|
|
Post by 4l04ever on Dec 24, 2023 17:22:50 GMT 1
Check the needle valve and seat.
|
|
|
|
Post by stirling11 on Dec 24, 2023 17:27:02 GMT 1
Ok, will do
What am I looking for ?
Thank you
|
|
ims
L plate rider.
Posts: 39
|
Post by ims on Dec 24, 2023 18:23:24 GMT 1
I would say polishing the inside and the head of the needle valve with a cotton bud and a spot of liquid brasso would clean it all out it’s most likely the seat off the valve and they can also get a bit sticky on the little side vain on the needle itself
|
|
|
|
Post by 4l04ever on Dec 24, 2023 18:34:58 GMT 1
Make sure there is no debris in the seat or on the needle.
|
|
|
|
Post by lcmarky on Dec 25, 2023 10:27:28 GMT 1
Could also be a sticking float if the float valve is ok or the float height.
|
|
|
|
Post by stusco on Dec 25, 2023 11:57:25 GMT 1
Is it a vacuum tap
|
|
|
|
Post by stirling11 on Dec 25, 2023 14:19:38 GMT 1
It's the standard Yamaha tap, which I think is vacuum
I'll pull the carby out and pull it apart and make sure everything is clean and go from there
I don't think it's the fuel tap as I'd expect both carbies to do the same thing if it was an issue there
Thank you for all the suggestions
|
|
|
|
Post by elsiefan on Dec 25, 2023 16:39:13 GMT 1
Do you have an LC or PV? LC is a manual tap (on/off/reserve) and PV are vacuum (on/res/prime) so if a PV check if it is on prime, as fuel will flow all the time. A few friends with PV's have had problems with their fuel taps, which if leaking could flood either, or both, carbs if there is dirt in the needle valve as well.
A good clean of the internals, test the floats actually do float, and check that the fuel tap doesn't leak in on/res position, should help find your issue.
|
|
|
|
Post by stusco on Dec 25, 2023 21:07:37 GMT 1
If its the vacuum tap better buy a new one instead of repair kit
|
|
|
|
Post by reedpete on Dec 25, 2023 23:16:19 GMT 1
If it only happens when the bike is running then it does suggest the vac tap is actually doing its job.
Have a look at the needle valve, see if the PTFE on the tip is worn , but also check the o ring … probably old and knackered …
Fuel can easily just go round the side of the float valve if that’s worn…
|
|
|
|
Post by stirling11 on Dec 29, 2023 17:16:10 GMT 1
Using a bit of reverse engineering, is it possible to clear any debris at the needle and seat by passing compressed air into the overflow tube ?
|
|
|
|
Post by reedpete on Dec 29, 2023 17:57:36 GMT 1
In a word no… you’ll just blast fuel up through the jets and make a mess !
It’s really not a big job to take a carb off and clean and check it…
|
|
|
|
Post by midlifecrisisrd on Dec 29, 2023 18:36:16 GMT 1
As above
The vent tube would vent the float bowl so would also feed the pilot jet, the main jet, the air jet and the bowl over flow
Steve
|
|
|
|
Post by tony2stroke on Dec 29, 2023 18:39:57 GMT 1
As has been said, symptoms point to needle valve problem, either worn needle tip, worn valve seat or maybe the O-ring not sealed, though maybe a leaking float.
You need to take carbs off and check these areas, you need to see what the problem is to fix it or you will be chasing your tail around.
There could be corrosion around the valve seat o-ring area interfering with the seal, it only takes a tinny bit of crud in the wrong place to cause a massive headache.
|
|
