Fueling problem pls help

[Gerrit]

I have 1x fuel filter in either sides fuel pipe leading from the petcock to the carbs. ( the fuel filter in the petcock was damaged)

Lately the bike will start running on one cylinder, and I could now easily identify that it is the rear carb that does not get fuel, as the fuel filter is visibly empty.

I did a vacum check on the petcock and it worked fine, so it seemed that the problem could be somewhere inside the rear carb.

At great expense I replaced the "needle-n-seats...still did not solve the problem...

I then noticed that the vacuum pipe on the rear carb had a nasty -kink- I thus pulled this hose from its resting place between the 2 carbs, so that it just hangs loose...voila the fuel started flowing and for 2weeks now the bike was as smooth as silk.....Until

This morning - went out for a ride and all of a sudden onto 1 cylinder, stopped and checked, and yes the filter was dry, once again no fuel in the rear carb...

I am at my wits end...what else could it be?

Many thanks in advance
Gerrit
http://www.formulagti.com

[Gerrit]

Yeah all the pipes are on, in the corret way, 2x fuel pipes, vacuum pipe, vent pipe, and overflow.

The carbs have been stripped cleaned, all diaphrams are perfect.

[mark skett]

HAVE YOU TRIED IT WITHOUT THE 2 FUEL FILTERS ON. IF THIS IS THE PROBLEM JUST GET THE FILTER FOR THE TANK

[tony.mon]

As it's a gravity feed from the petcock to the carb, I'd be looking at the petcock.

Assuming that the filter on the rear fuel line is (heightwise) still between the petcock and the carb inlet, then if it was the float needle sticking then the float bowl would empty but fuel would still be in the filter.

As it's not we can assume that fuel isn't reaching the filter, which means that it has to be the petcock, or a blocked pipe between petcock and filter.

You say that you've vacuum-checked the petcock, but are you sure that the petcock passes fuel to both sides when the vacuum is applied?

Lastly, the old favourite: Is the vacuum pipe attached at the 9 o'clock pipe on the petcock, not the 6 o'clock one? (the 6 o'clock one is only a vent/drain).

[Gerrit]

Thanks for the replies guys....

Firstly I enquired at the HONDA dealer for a new "strainer", and they can only supply the complete petcock at R2780.00 which is a ton of cash in our currency.

I have had the tank off and on the table, and if I suck on the vacuum hose the fuel flows in similar volume out of both the left and right fuel hoses.

The filters are located halfway on each fuel hose that leads from the petcock to the carbs.

There always remain a small bubble of air in either filter, perhaps that is the problem.

I will try it with removing the filters and see if that changes anything.

However, I have noticed on removing the carbs that the rear cylinder is wet with fuel, so I still think the rear carb somehow lets the fuel thru.....

I also noticed that my oil level has been dropping, and that would happen if fuel gets down the cylinder/s, as it will thin out the oil.

Regards,
Gerrit

[tony.mon]

Gerrit, I think you might have the opposite problem, if you mean that the outside of the rear cylinder is wet with fuel.
That would indicate that the rear float isn't cutting the fuel off.

That would certainly stop the rear cylinder from working, and the excess fuel would then leak out.
If fuel was leaking past the rings, past the piston and into the oil it would RAISE the visible oil level, not lower it.

(but this doesn't explain why there was no fuel in the in line filter) so

[sirch345]

Most of the things I would suggest have already been said. Float level I don't think has been mentioned, so may be worth checking. I think most if not all fuel filters never completely fill with petrol.

Have you ever pulled the spark plug from the front cylinder when it's not firing to see if it's wet with fuel

Chris.

[Gerrit]

Warming the bike befire work this morning I used the choke, and it giot me thinking..

Could a sticking choke be the problem?

Gerrit

[sirch345]

Definitely worth checking out the choke operation. It's a two into one cable set-up. Be careful if you decide to check the parts that fit to the carbs, they can be broken if care is not taken.

When it's not firing I still think you need to pull the front spark plug to see if it's wet

Chris.

[Gerrit]

Problem solved......

By adding in fuel filters on the fuel lines..the lenght of the fuel line has been extended, and I was too blonde to realise. When the tank is put in position the right side fuel hose, would king upwards, close to the petcock....and I never noticed.

The fuel wouldn't flow upstream....damn ...any way all is well now.

Next question......

I received a new Dyno jet kit.....is it worth in stalling.....?

On my bike there is a K & N Filter and a 2 into 1 Yoshimura.

Thanks in advance Gerrit

[Phil-VTwin]

Glad you spotted it and got that sorted

I would say YES to the dynojet kit with the K&N and exhaust and use the 180 main jets to start with, not sure if you need the 190's but perhaps another member with the same exhaust can let you know.

[sirch345]

Good to hear the outcome
It's quite often the simple things that catch us out

I've not altered the jetting on my bike yet, so will leave the others who have to give opinions on that

Chris.

[Gerrit]

When the bike is idling, to warm up in the mornings. one can hardly breathe with the exhaust fumes filling the air, it seems that it is running very rich, my nostrils are burning so bad it is, however, once on the road, the bike is pulling smooth, no indication that it's running rich.

[sirch345]

If the choke is still being used it will be running rich. Are you starting it up in the garage

Chris.

[Gerrit]

No I start the bike outside the garage, and I do not use the choke, damn it is potent man, the fumes will kill me. Does it have anything to do with the mixture screws, mine are 2 1/2 turn out. Gerrit