GSXR 400 Airbox

AcePepto · L Plate Warrior Joined: 12 Jun 2010 Karma :

I recently bought an '89 GSXR 400 and when i got it home and took a decent look at it, i noticed that the person who had it before me had cut a slot in the side of the airbox so they didnt have to disconnect the throttle cable before removing the airbox, and that the plastic seals between the carb and the airbox dont sit in the airbox tightly.

Is there any harm in riding without the airbox on it, or is there some individual filters i can get for it instead??

Pete. · Super Spammer Joined: 22 Aug 2006 Karma :

YOu need filtration or you'll pull in dust and dirt which will grind the engine internals to bits. Best bet is to find a replacement airbox. Ask about on 400greybike
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good Very Happy

temeluchus · World Chat Champion Joined: 01 Oct 2008 Karma :

Airbox is your best bet. You could get individual filters, but this WILL need messing with jetting.

You could repair the box with sealant (black RTV silicone or similar).
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Some shite cruiser. Now with guns and FREEDOM!

AcePepto · L Plate Warrior Joined: 12 Jun 2010 Karma :

Thanks guys i'll check them out, its not running right anyway so im gonna have a look at the jets etc.

Also i've noticed that there is a knocking coming from somewhere in the engine when i drive faster than 45mph, the front sprocket is slightly loose because it isn't held on in the same way modern ones are, so i think it's either that, or the cam chain. Any ideas?

Pete. · Super Spammer Joined: 22 Aug 2006 Karma :

Cam chains don't knock. What's up with the front sprocket? Many aren't held solidly on the shaft but they don't knock usually either.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good Very Happy

AcePepto · L Plate Warrior Joined: 12 Jun 2010 Karma :

The sprocket is only held in with what looks like a circlip, there isn't a nut and washer on it, and theres a bit of play on it side to side. There is a knocking from somewhere that's quite fast, but it only knocks when im doing over 45mph which is quite odd. It's kind of hard to describe properly without actually hearing it. Sad

Also, i can't find online anywhere what the jet sizes should be on the carbs, because i don't think its running right, and i also can't find how far out the fuel/air mix tap should be turned from stop. Any ideas?

V2 · Nearly there... Joined: 06 Feb 2006 Karma :

If its not running right before messing with the jetting and such forth read this, could save yourself a lot of bother! https://tonysleep.co.uk/gsxr400carbs

AcePepto · L Plate Warrior Joined: 12 Jun 2010 Karma :

Thanks superretard, i'll read over that and see if it helps sort it out Very Happy

boundy · Nearly there... Joined: 24 Jan 2009 Karma :

Before messing about with the carbs you might want to sort the airbox out, this might be the cause of the running problems

AcePepto · L Plate Warrior Joined: 12 Jun 2010 Karma :

I've bought a new set of carbs from eBay, and i'm going to see if I can get them to run right, because I think the seller said that they had already been set. But if that doesn't work I know someone who has a dyno and I think he can balance carbs aswell, so I can always get him to take a look.

Thanks for the help everyone Very Happy