Kill that 'cat'!

[bonester]

The catalytic converter on my ZRX *ahem* fell off. (with some encouragement of a grinder) Not much increase in power (3Hp going by the owners manual that says that the Malay model without the cat has 3 more) but seems smoother. Best thing though is a 2km/L fuel economy increase- 15km/L maybe better when behaving.

[photomike666]

Is it now running lean? and how much louder is it?

I've considered this mod for the 10, but don't want to have to get a PCIII (yet) and I don't want fark off loud. If set the wifes car alarm off yesterday morning at 6:30am, and all I did was park the bike to shut the garage door!

[bonester]

Can't tell if it is running lean. It isn't any louder as far as I can tell. Looking at the service manual, the Malay model without the cat runs the same jetting etc.

[BrisZX9R]

STUPID QUESTION TIME:

a) Where would I found the catalyst converter on a 2002 ZX9R

b) What the hell is it for?

c) Will it affect the bike, other than maybe running leaner or getting more fuel economy?

[J.B]

STUPID QUESTION TIME:

a) Where would I found the catalyst converter on a 2002 ZX9R

b) What the hell is it for?

c) Will it affect the bike, other than maybe running leaner or getting more fuel economy?

If you have a ZX9R C/D manual read from 1-9 onwards and you will get the answers you seek (I think the emission control was the same for your model).


As for the cat on the ZRX any chance of a few pics/ write-up?

[bonester]

Haven't got any pics but it is dead easy. Take muffler off and the cat is staring at you in the end of the headers. Grind three tack welds off and it's out.

[bonester]

(someone elses bike)

[J.B]

hmm...

Picking up a stock '02 rex tonight, might have to break the grinder out over the weekend.

Thanks mate.

[BrisZX9R]

J.B: I dont have a CD for my bike, I got it 2nd hand. ...... However my brother just flew in from the US (he lives over there, comes in handy for shopping) with a Hanes ZX7R - ZX9R '94-04 manual. all for $20

JB...and... Bonester and any others:

... anyway I was reading about the cat converter.. and it's created more questions than answers.

I already have the main cat out, as I have a D&D slip on. The pre-cat converter I think I took out when I out the D&D on, so thats all covered, however the manual says my bike has a fuel cut off valve that is meant to work with both catalytic converters. Am I meant to get a mechanic to dis-engage or remove this fuel valve? it's designed to prevent excess fuel being passed into the exhaust system according to the manual. However they only do this to prevent the pre and main cats from getting to hot and melting, again according to the manual.

Also what the hell is a californian model??? is that because they are serious tree huggers over there and it has tighter emission restrictions? and is it in relation to the name ONLY sold over in the US? or do we have some out here?

Sorry for more stupid questions guys, I am not really that mechanically minded.

[J.B]

You are correct about the Californian models, they have tighter emission targets than the rest of the US and I'm pretty certain they are only sold in Cali.

As for the Fuel cut-off valve, I think, don't quote me, that it only operates to prevent run-on. So only operates under specific conditions like when the kill switch is activated while still running, i.e coasting. In this case the fuel would still be sucked into the engine but with no spark so it all ends up in the exhaust which is bad for the cat's. Don't ask me why anyone would ever do that, but the system is there just in case.

There is however one other bit of emissions control which is usually removed when modding bikes with carbs, and that is the so called secondary air injection system. It consists of a vacuum switch and some reed valves which are located somewhere on the head. It works by allowing extra air directly into the exhaust port when there is pressure behind the vacuum switch, occurs when you are off throttle. The additional air in the exhaust allows the unburnt fuel in the exhaust to combust before reaching the converters. This system is removed by taking out the reed valves and installing block off plates, and removing the vacuum switch and blocking all the vaccum lines assocciated with it, pretty sure that's it. A good mechanic might even do it for you.

HTH.

[BrisZX9R]

JB.

thanks for that... I will have a chat to my mechanic and see what we can do.