Project My Fizzer

This diagram shows the pilot circuit reservoir, concealed underneath/above the small plug in the carb body and labelled to the right hand side of item number 6.

If your needle and seat valves are misbehaving intermittently that is the first orifice that will leak fuel down to item 7 and into the engine.

I'm still putting my money on needle and seat valves, but will know for certain when mine arrive and get installed.

It's the ONE item I looked at when cleaning the carbs and should have listened to the voice in my head that said replace them.
24 year old plastic and rubber that's been coated in gunk for an unknown number of years while the bike has been left sitting...

peace out

 

We've been down the same path. rebuilt the carbs with all the Litetek gear so i ruled them out as a cause & the problem persisted, mucked around with the mixtures like you & seemed to improve things but nah, re fitted the air box & seemed to improve but nah, replaced the plug caps & made sure they were in correct firing order but again nah. Started to think what else, next option was electrical timing, don't know if they're adjustable or troublesome but something to consider.
In my case it was simple, it came to me in the middle of the night, bloody spark plugs. I had checked them & cleaned them etc but failed to check the spark, anyway I replaced them on Christmas eve & it's perfect, in fact I'm shocked how well it goes. All the hard work has payed off, it's an awesome little rocket.
I did nothing more than set the carb balance off the bike with a thin wire as a feeler gauge under the butterflies & they're perfect.
Anyway, got off the track a bit sorry, I've set all the mixture screws at 3 turns out & no issue there.
The only mod is a Blue Angel muffler, std inlet filter so stock settings are ok.

 

I've cleaned and gapped my plugs - seems Santa gave you an idea for Christmas, so I'll replace mine - that's a good idea you've had there

 

An un believable thing happened Christmas eve , the local Auto Barn had 4 in stock at $4 each at 3;30 pm.
My bike was a new acquisition so unknown quantity as far as how it went & what had been done to it previously, wasn't going when we picked her up, water in the tank & carbies & looked bad
Turns out now having worked on her intimately she has been loved in her earlier life & barely touched, I'm guessing the last owner neglected her for a few years
Not knowing how these things were supposed to go we struggled a bit with the tune, seemed like it wasn't firing on all 4 but plugs looked ok. Rode her a couple of times & noticed in the end that 2 plugs were black & 2 were clean, sure enough those 2 were crook, one was dead & the other was weak, amazing how they'll go on 2 plugs. had a similar issue with the zxr when 2 leads were out of order & she still ran!
For $16 it's worth a try, at least it's something else to rule out

 

Something else we found was the leads were just sitting loose in the coils, they just push in onto a pin, funny setup, we thought they might have been aftermarket replacements but I'm sure they're originals, so we Araldited them in securely, snipped 10mm off first of course.
Thry were a pretty loose fit which allowed a nice amount of epoxy to get in around the leads & hold them for ever more. 5 minute Araldite is the best

 

Ok that explains a lot.
Those leads look a lot heavier than mine & no clips, they're gone.
With the clips off, do the leads just pull out ? on mine they just push onto a pin, not screw ins like the plug caps.
My leads are fairly thin & stiff but fit the cap rubbers well for a watertight seal, maybe theyve been replaced, definetly not soft floppy silicone leads but whatever they are they work because the engine sings right through the rev range, music to my ears, still cant believe it goes so well.
Have ordered a clutch kit as she's slipping so no riding her till then, I'll need a cover gasket & was going to order a genuine one from the dealer off a FZX / Zeal, do you know if that will fit, is that what you guy's do for genuine replacement parts? I have to do the fork seals & that's what I'm going to do there also ??
Looking at the Zeals in pictures they look like the same engine, swing arm & front end but they seem to have been imported 91 to 99 which fits nicely for my 90 3LN1
Keep us up to date on your findings, interesting to see what you find, remember to only replace one item at a time so you know what fixed it.

 

Thanks. I found the part number for the clutch cover gasket off the Zeal site.
How do FZR parts get ordered if they don't exist in the dealers catalogues as per below ??
JOINT, AIR CLEANER
3LN-14453-00 x 4 on order from my local Yamaha dealer
$11.30 each .... which is ok when u factor in shipping with the other sources.

 

Just an FYI - my order with partzilla is still awaiting delivery to them from Yamaha - worst possible time of the year...

In the meantime I found another source for parts comparably priced - www.motosport.com - and their system shows their stock levels - prices in both cases are both about 50% of locally available parts prices even with shipping costs

I'm a bit disappointed that Australian Importers and parts suppliers haven't realised that there's this thing called the internet and that they need to be price competitive with overseas parts sources

 

I,ve used Partzilla & they were good, I remember comparing MotoSport at the time but their shipping was too high.
I'm still confused, they don't list FZR250 stuff on either site ??
As far as the Aussie prices go, I'm sure it's the importers that are sticking it into us not the dealers, for too long they've had a monopoly & it forces the dealers into minimum profit margins to keep the costs reasonable so the public can actually afford to purchase the parts, that's not to say if the importers dropped their margins that the dealers wouldn't then jack up theirs, the internet should even things out eventually

 

Ok I've found the parts catalogue in 'Resources'
I'll try some of those numbers on the local dealer but from past experience I'll bet I just get the old 'computer say's nah' & that;ll be it. If it was a Kawasaki It'd be a different story, thay are very helpful here.
If I don't do any good I might try Tamworth, is it Ride Motorcycles ?

 

It's all down to actual part numbers, my carb parts have 3gm prefix and are used in the YZF750 all through the '90's.

I must belatedly thank Grey for pointing me straight to the part number I needed and the partzilla link...thank you Grey.

I also tried the suzuki equivalent part number that I found on the zeal site but had almost no luck with that one.

Also 3ln part numbers will crop up on other models, I'm not certain what the protocol is, perhaps it's the first use of a part on a model - designates that parts number on other later model bikes.

 

yep he means the vacuum diaphragm slides - needle and seat valve not shutting the fuel off when coming to a stop after higher engine speed and then flooding through the pilot circuit.
Opening the slides allows more air through clearing the congestion quickly.

I can replicate greys symptoms by just using the fuel tap and just turning it on and off

fix = equals new needle & seat valves