Strange Loss of power

[Guest]

Hi,
Having an issue with my Cafe 82 1100g. When revving the engine on the centre stand or with the clutch in (no load) the engine revs to the redline no problem. However when riding her she struggles to rev freely.
In first she stops at 9k, second 8k, third 7k, forth 6k and fifth she runs out of grunt at about 5k.
I have rejetted her and all was good for a while. She has a new clutch, new ignition coils, new plugs and new fuel filter and petcock.

Its ts a really weird fault and has me stumped. Any ideas? Was thinking float level next as that was the only thing I had not changed or set up, but can't see the link with the symptoms I have.

Thanks

[tom203]

By "new fuel filter" do you mean in addition to one on petcock?

[Dicke]

Yes, I fitted a normal inline filter from tank to carbs.

[Steve]

Please define "normal".

Suzuki never fitted one, so there is no factory "normal".

If you went to Auto Zone and got one meant for a car, that could easily be your problem, as they are rather restrictive. All cars have fuel pumps. With fuel injection, the pressures are in the 40-50 psi range, which is plenty to get the fuel through the filter media. Our "fuel pump" is GRAVITY, and it only has a head height of about a foot, so pressure is minimal. The filter on the inlet of the petcock is sufficient, but you might want to check that it is there, intact and not clogged up. There is another filter on the inlet to the float valve of each carb, so fuel is already run through two filters, there is no need to add a third.

.

[rudeman]

Are the specs for the new coils within the range specified for your ride?

[Dicke]

Since I bought the bike there has always been an "extra" inline fuel filter. I just replaced like for like with a generic one. I will remove the extra one. New coils were 3 ohm and seemed fine. I did swap back over to the old ones, but the fault still remained, so I discounted that theory.
Plugs are all a good light brown, no soot or black, or wetness. Just seems fuel related but cannot pinpoint it.
Does anyone know what the exhaust CO reading should be? Will try and find a gas analyser maybe.

[Nessism]

How long since you last adjusted the valves?

[Grimly]

Please define "normal".

Suzuki never fitted one, so there is no factory "normal".

If you went to Auto Zone and got one meant for a car, that could easily be your problem, as they are rather restrictive. All cars have fuel pumps. With fuel injection, the pressures are in the 40-50 psi range, which is plenty to get the fuel through the filter media. Our "fuel pump" is GRAVITY, and it only has a head height of about a foot, so pressure is minimal. The filter on the inlet of the petcock is sufficient, but you might want to check that it is there, intact and not clogged up. There is another filter on the inlet to the float valve of each carb, so fuel is already run through two filters, there is no need to add a third.

.

I'd rather replace a proper, decent-sized, inline filter from time to time, than root around inside the carbs fiddling with trying to replace the daft little easily-clogged mini-filters in them. As for the petcock filter, it's good at filtering out rocks. A decent inline filter will allow more than sufficient fuel to flow, even with less than a foot of head. Having said that, the vast majority of inline filters sold for bike use are useless pieces of crap, so I see your point there.

[rudeman]

What's your induction set up? Is it stock or have you altered in in some fashion?

Have you pulled your carbs and visually inspected them?

[Dicke]

I have replaced the air box with pods. The bike took some time to get it sorted, but the fuelling seemed spot on. Mains changed to 155 outer 152.5 inner cyclinders. Pilots were standard, and needles dropped1 slot, with a spacers in the stack as well.
Running 4into 1, and a baffled reverse cone end .

[retcol]

I've had 3 1100G and 2 1100E bikes, some with pods, and i think, from my experiences, you are running way too rich. I recommend you drop down to 135 and 137.5 jets and put your needle back.

[Dicke]

Right carbs have been stripped down and checked. All good with no muck or dirt any where. All jets clean and free.
i did notice tonight coming back from the Cafe that the bike pulled much better? Could this be a temp/ mixture issue?. Would I need to unscrew the mixture screws or tighten up to increase the air content. Is my thinking correct. Colder air is more dense so need more air in the day, therefore need to increase oxygen content and lean up the mixture.

[Dicke]

Thanks retcol. Stripped the carbs and fitted the original main jets back in. Pulls now into the higher revs in any gear. Waiting for the 135 and 137 jets to arrive.