1wg 1988 FZR400 carb query

[adibtanah]

I can't get bike to perform at high revs. It goes fine from low revs to about 10k then justs does not go any further from 4th gear onwards. the bike is not restricted, we dont have those limitations in South Africa. Have replaced manifold rubbers, air filter, fuel filter, plugs, oils etc. The bike is stock and has 48 000km on the dial. It starts perfectly in Winter without using the choke and does not smoke at all. Mechanically it is sound, but I think the carbs need attention. I stripped the carbs today and found that 2 diaphragms have tiny holes in them. The needles have signs of wear on them. The jets look fine. I have orded a carb kit from Factory Pro in the states with emulsion tubes.

- Mikuni 3EN 00 E8212 Carburetor (Markings on the carb)
1. I need to find out where can I get new diaphragms from???
2. The most important question what is the float height using a vernier caliper???
3. How do I remove the emulsion tubes
4. How many turns for the pilot air screws 2 1/2 or 3 1/2 turns out?
I would appreciate help on these 2 topics.

Your help will be much appreciated
Adi B

[Marb]

Not revving above 10000rpm is one of two things. Too much fuel or bad diagphrams. What setting where the jets on.

New diagphrams are ridiculously expensive new, best bet is to get a cheap second set of carbs and use the diaphragms from those.

For the floatheight. Thurn the carbs upsidedown, so that the floats are ontop. With the backside of the vernier, measure from the gasket seating to the top of the float. That is the float height, and can be adjusted by carefully bending the little metal lip up or down.

The emulsion tubes should just pop out with a little tap with the back of a screwdriver or small rubber mallet.

I'll look up the pilot air screws this eavening when i'm home. I think it was 2.5 turns.

What are the jet sizes that are in the carbs? Could be that you have a set of FZR600 carbs on there.

I'll get some pics up tonight, im working on my carbs too atm.

[adibtanah]

2 of the 4 diaphrgms have holes in them tiny but obviously are holes. Not too sure but the one jet says 0.88mm then the other is 5.25mm the needle is 5CFZ. The carbs and everything is as it came out of the factory. The bike is original standard Fzr 400 1WG 1988 and as per model spec 3EN1. I will get diaphragms from local spares. I have two workshop manuals, one says 2 1/2 turns for the pilot air screw and the other says 3 1/2 turns? The 2 manuals I have is the 3TJ ME1 and the other is for the California spec 400A and 400SAC??? Both vary on specs. Anyhow I appreciate your help and hope to get the correct settings for this beast, because we all know that the baby moves like shit off a shovel!!!! Mine is in prestine condition and just love the playing around feel from this bike. All my mates have new suzuki 1000's and yamaha r1's but let them get to the track and I'm all over them through the bends!!!! I want to keep the bike original, but want to fit the Factory Pro carb kit, the timing advancer, gear shift gismo just to give the extra edge over the other Suzuki GSXR400, VFR400 that are still running in my hometown, and so they can kiss my butt!! The only FZR's you see in my town are maybe 3 or 4 750's. I am the only one with this specific 1988 1WG 400, and I feel special having this beast, that's why I want to get it right and preserve the awsome engineering that went into producing this bike. Thanks for your help and will keep in touch.

[Marb]

You dont need the 3TJ manual. The 3TJ is the 91-94 FZR400RR. So then my memory serves me correctly, it is 2.5 turns.

The factory pro carb kit is a good piece of kit. Together with a K&N replacement airfilter she breaths so much better and picks up much better.

Small holes in the diagphram kan be fixed with simple bike innertube glue. Did it with my dad's XS750 diapragms and a year later they are still sealed up.

[adibtanah]

To Marb,

Thanks for the advice, I got some tube patching solution and have applied it on both sides, I hope this works. The bike harldy gets used, only maybe twice a month when we go out for a ride to escape the rat race. Still though just need those float heights. I have 2 manuals, the 2 1/2 turns is for the 1991 + models and the 3 1/2 turn looks like the correct one for these carbs as the manual shows a FZR without ram air pipes, so this would be a slightly older bike than mine.