'94 FZR600 Derestriction

dr_chriz · Two Stroke Sniffer Joined: 17 Mar 2004 Karma :

Hi all,

I've got an FZR600 and it has an annoying FI International restrictor in it. I know that there are two sorts of restrictors that they do, one for the carbs and one for the exhaust, fairly sure that it is the carb sort that i have.

I was wondering how difficult it is to remove these and also where exactly they are? I have taken off the air box and was assuming they were seated on top of the carb but no sign of them. Just one final thing, if i do remove them will they break in getting them out? The official website says they will but don't think i really believe that and i could do with them back in for the next MOT etc.

Thanks

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

Hi dr_chriz! Welcome to the forum.

The FI international restrictors are always just small washers in the intake manifold (unless its a REALLY powerful bike like a TL1000 or something where they put a throttle stop in too). You need to remove the carbs and lever them out of the carb rubbers which will be left on the intake manifold. Unless you completely dismantle the carb rubber assembly and remove them, you WILL damage them. They are not needed for an MOT and they won't check for them. The only thing is if the police ask to inspect your bike, and thats when they would need to go back in, but the chances are the police would have the bike away too quickly for you to do anything about it.

IF you do go ahead and derestrict it, then the carbs will need to be balanced and the bike could probably do with a service at the same time to get the best out of the new unrestricted performance.

Remember, if you decide to do it, it is your own decision and you have to know that you will be riding without a license and technically uninsured. If you have ANY doubts about it I would say leave them in and wait for your two years to be up.

Good luck! Smile

____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

dr_chriz · Two Stroke Sniffer Joined: 17 Mar 2004 Karma :

Ok mate, thanks for that, think maybe it is fast enough for now then. Have to see how it performs at a BCF meet tho......
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"It'll be alright in the morning"

Robby · Dirty Old Man Joined: 16 May 2002 Karma :

Couple of things there.

The carbs won't necessarily need to be balanced. The carb balance is controlled by the balance screws, which won't be disturbed, and seeing as all the washers are the same, removing them won't affect the carb balance.

Also FI do do exhaust restrictors, I know for a fact they do an exhaust washer for the virago 535, which just sits at the top of the header pipe. It also rattles like a bastard if you don't put it in place with a couple of spot welds.

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

Robby,
When I had my VFR restricted all of the washers were different tolerances and so were balanced differently with the washers in than with them out. They evidently needed balancing when they were put in, so it stands to reason that they needed balancing after they 'fell' out.

I only speak from experience. Smile

____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

Ste · Not Work Safe Joined: 01 Sep 2002 Karma :

I wouldn't expect a bike shop to adjust your carbs for them, as all four washers are the same, and all four carbs should be set the same to start with. I specifically told the shop not to change any settings on anything when they put mine in.

Ahem, Mark, I know nothing about things like throttle stops on TL's. Wink

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

The bike shop that restricted my bike did balance the carbs and therefore they needed balancing again when the restrictors 'fell' out. Capisce? Cool

____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

dr_chriz · Two Stroke Sniffer Joined: 17 Mar 2004 Karma :

Ok, derestriction covered. I was wondering if anyone knew what speed the FZR makes derestricted, i've got 120mph (on a track of course) on mine, is this normal for a 33bhp restricted version?
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"It'll be alright in the morning"

MarJay · But it's British! Joined: 15 Sep 2003 Karma :

it shouldn't go faster than 100mph 33bhp. but Yamaha Speedo's have been known to be optomistic after 70 anyway.
____________________
British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

McJamweasel · BCF Junkie Joined: 22 Mar 2002 Karma :

FUll power they're about 145mph I think.
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BCF: Be yourself, just don't be an arse.

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Probably on a genuine 33hp at the rear wheel it should manage around 105~110mph true, and quite a bit more than that indicated. 120mph indicated is probably about right in favourable conditions.

All the best

Keith
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