GN125. Change from airbox to a air filter.

[Jadakemi96]

Hi I have a Suzuki gn125. Not for speed its just for looks... but I want to get rid off the air box and change to a filter. Whats the best way to do this.

Thanks

[fastbob]

Take the Airbox off and put it in a safe place . Remember where you put it . Stick a suitably sized conical filter on the carb , tighten the Jubilee Clip and , hey presto ! Job done . Now you can spend hours experimenting with different jets and carburettor settings until the bike runs properly again . Don't forget where you put that Airbox .

[Ian Frog]

Take the Airbox off and put it in a safe place . Remember where you put it . Stick a suitably sized conical filter on the carb , tighten the Jubilee Clip and , hey presto ! Job done . Now you can spend hours experimenting with different jets and carburettor settings until the bike runs properly again . Don't forget where you put that Airbox .

 

Utterly brilliant Bob I could hear the years of experience and frustration bleeding out of that comment.

For the record I agree put a big post it note on the inside of the garage door telling you where the air box is !

Cheers

Ian

[dynax]

Better still leave it on the bike where it is

[Tiggie]

I'll just add to this that the people who are replying aren't being dicks but are speaking from experience

It certainly can be done and Is pretty much as [mention]fastbob[/mention] described.

Fit the cone, go for a spin, pull the plugs and look at them to see if you are running too rich or too lean. Will most likely be running too lean. Take off the carb, fit new jets, go out for another spin, pull the plugs and check them again. Repeat ad nauseum until its running right

[Ian Frog]

Back in the day we even used to put faith in things like Gunsons colourtune and other things to sort out carburation that we had basically wrecked by playing with early K&N`s or bell mouths.

Don't get me wrong there is a very valid place for these things but usually in conjunction with a lot of other mods and use at the upper end of the performance of your engine.

Listening to the local tuning god back in the 70`s just cost time and money and it transpired gods usually have feet of clay !

Lol I hope you have fun with it.

Regular covering of the baffle in petrol and burning on the drive is a great way to decoke it as well ! (Castrol GTX tin of fuel will go a long way and leave the handle in your hand when you shake out the dregs lol).

Cheers

Ian

[Jadakemi96]

Thanks all.

If its running to lean do I go bigger or smaller on the jets?

I just hate the look of it think it looks pretty cool with a cone filter.

[Tiggie]

Running lean means it needs more fuel so will want a bigger jet and/or altering the pilot screw. Remember not to throw away the airbox

[Jadakemi96]

Definitely know where the box is haha.

What do I do with the 2 rubber pipes. Both was connected to air box. One is attatched to the engine and other goes under tank somewhere.

Thanks

[Tiggie]

That'll be the vacuum hoses for the petcock. I'm not actually sure if there is a workaround for what to do with those besides swapping the petcock for a non vacuum one.

Someone else who hasn't been day drinking want to help out?

[Jadakemi96]

Any help would be great.

Thanks guys

[Snod Blatter]

I'd be amazed if the GN125 has a vacuum operated fuel tap, my GS125 was decidedly normal/manual. I'm not sure what that other pipe would actually be though!

[mention]Jadakemi96[/mention] is the carb CV or normal slide type where the cable pulls the slide up? If it's CV you are heading into a world of pain but don't let us stop you

[Ian Frog]

Is one of the hoses connected to the top of the gearbox area? I hope that would be an oil breather which should go into the airbox that you have carefully placed to one side for later.

Back in the day these were then put into Fosters cans or imitation Newcastle bottles or all sorts of amusing things to prevent the oil mist going over the rear tyre.

If the other hose is a vacuum hose and you have CV carbs stop now and retrace your steps !

I promise you will soon enough.

Said by the idiot who ran pod filters on a Z1000J and ended up sending the carbs to Pip Higham at the village bike shop as I couldn't get them running right.

Cheers

Ian

[Jadakemi96]

This is just temporary to see how I got on. I ripped up a new washing up sponge and plugged both pipes. After a ages of figuring out how much sponge to put in. It seems to be running sweet. Up to 2000rpm is a bit boggy but absolutely fine after that. Also another temporary trial was taping 3 quaters of the cone in electrical tape.

[Jadakemi96]

Seems okay for now

[Tiggie]

It looks better with the box in my opinion!!

Original

 

 

Newly modified one

 

 

I hope you keep the airbox for when it's time to sell

I'm only lightly joking of course, in the end it's your bike and you should do what you want with it. I'm just speaking from the experience of wishing I hadn't done a lot of things to mine which at the time I thought looked good

[Copycat73]

be sure to carry a tin of wd-40 for when it rains and you lose power .. and save up some coin for your expected re-bore .. as the dirt ingress because of that filter will wreck the combustion chamber..