odd happenings

[Guest]

Hi I have just completed the carb overhaul on my GS 850.Followed the instructions I downloaded from BikeCliffs website to the letter.New everything ie "0" rings,jets...etc.Worked a treat bike now runs and starts great.But on turning the ignition key off I get a cough from the exhaust?????? any ideas please.

Regards Warriormonk

[tom203]

Leave ignition "on" and turn off with kill switch- same thing?

[Steve]

Have you done all the fine-tuning on the mixtures?

Have you adjusted the valves?

Have you done a vacuum sync?

.

[warriormonk]

Odd Happenings

All checks carried out by mechanic.I turn engine off with kill switch, if I then wait a minute or so then turn off the key it coughs from the exhaust.It runs a dream so can not be much.(famous last words)

[tkent02]

Why not just turn the engine off with the key?

[warriormonk]

Odd Happenings

Same result.

[tkent02]

Is this a breaker points ignition 850 or an electronic ignition 850?
Also I am curious why you would replace the jets, and what you replaced them with?

[warriormonk]

Odd happenings

I was having trouble starting it and it ran like a sack of frogs.I read the forum that advises a total clean and replace of every thing.As the machine had stood a long time there was a bit of muck and one spring missing completely.I bought te byke to do up you understand.So thats the reason for the jets etc.Replaced with OEM stuff all Suzuki parts.

[tkent02]

I read the forum that advises a total clean and replace of every thing.

Which forum was that?

I bought te byke to do up you understand.

No not at all.


Points or electronic ignition?

And did all of the replacement jets have the same numbers on them as the originals?

[warriormonk]

Odd Happenings

electronic ignition,yes to numbers

[warriormonk]

Odd Happenings

it was on this forum about 12months since

[hjfisk]

it was on this forum about 12months since

This forum does not promote the changing of stock jetting, only with mods and then it is a jet kit. On a carb overhaul/ rebuild, it promotes a total strip and dip and replace the bowl gasket and o-rings, just clean your jets. The reason is jets don't go bad just get dirty. And after market ones don't tend to be the same. Also this sounds more like an electrical issue to me. My guess is a ignition switch, shorting inside.

[habsdoc]

Replacing the jets and needles is not needed as long as they are in good shape, (ie) no broken tips on the needles. If mods to exhaust or air intake (pods), then yes you may have to up the jet size. If not, then just a good dip and thorough cleaning with all new "O" rings should suffice.

[tom203]

To clarify-So if you first turn off with kill switch, engine dies, but then turning off ignition switch, engine fires briefly ?? Is the kill switch still in "OFF" spot when you turn off ignition switch?

[JTGS850GL]

If I understand it correctly, you get a pop through the exhaust after a minute or so of shutting down the engine. Does this always happen at the moment you turn the ignition key off or does it happen if you do nothing with the ignition key?

Another words either:

1) You shut the engine down from an idle using the switch on the handlebars. You then shut everything down using the ignition switch and as soon as you turn the key you get a pop through the exhaust.

or

2) You shut the engine off using the switch on the handlebar and then turn off the ignition. After a few seconds, you hear a pop through the exhaust.

Which one best describes your situation. If it's number 2 then you may have a rich idle with an air leak in the exhaust.

I've seen Mazda RX3's that did this if you depressed the accelerator peddle after engine shut down. This is kind of fun to play with. You turn the engine off, press the accelerator after then engine has stopped and then, after a few seconds, you get a loud bang in the exhaust. This happens usually in a long enough time that you’re already walking away from the car. Usually scares the pants off of anyone near the car when it goes off. Fuel gets dumped into the exhaust and the hot exhaust ignites the vaporized fuel once the correct amount of oxygen gets into the pipes.

Just a thought.