1990 FZR 1000 starting fault/fuelling ?

Post by **nuggitt** » Wed Aug 07, 2019 10:00 pm

You could try these.... CARB JETS

Or these... Allensperformance

When I started doing my carbs. I had the same trouble so I went to Halfords and took a spare jet with me and bought a good fitting screwdriver that was a tight fit in the slot. Not had any trouble getting them out since.

Keep using the spray and it should help loosen them up.

Post by **Stig** » Wed Aug 07, 2019 10:33 pm

Use some heat around the casting where the jet is as you try to turn it out

Fatdog · Post by **Fatdog** » Thu Aug 08, 2019 12:59 pm

As Nuggitt has said, the key to it is using the correct fitting screwdriver.
Push down hard on the screwdriver as well as turning to ensure it stays in place.
With the heat and spray they should come out.

phfzr · Post by **phfzr** » Thu Aug 08, 2019 6:39 pm

as I have the carbs in bits, is standard jetting the optimal set-up for a stock bike in the UK ?

As a recap, mine is a 1990 3GM

I have the observed the following

125/122.5 Main jets
60 starter jets
40 pilot jets
?? pilot air jets (not removed yet !)

it appears bikes for other EU Countries were fitted with slightly larger 127.5/125 mains

phfzr · Post by **phfzr** » Fri Aug 09, 2019 6:59 pm

I managed to get the Pilot air jets out after soaking with Kroil, good stuff recommended as its helped numerous times with seized items

Now that everything has been stripped, inspected, cleaned and ready for assembly, there is one aspect that I'm struggling with - below the main jets sits a square section o ring, all of mine are rock solid and stuck fast in the jet holder. I've managed to pry bits of it out, but fear damage to the seat. I need something that will dissolve the rubber, anyone encountered similar ?

phfzr · Post by **phfzr** » Mon Aug 12, 2019 8:42 pm

Fault is now cured

I hope this thread will become useful for any other users in the future

As a recap, the bike would start and idle from cold (using choke), and continue to idle when choke closed. As soon as any throttle input was applied, it would stall
I found the pilot circuit was blocked, in fact all four pilot jets were blocked solid. I was unable to clean them in the Ultrasonic bath, so bought new ones from the very helpful Steve at Motocarb in Liverpool

Whilst at it, as recommended by Nuggit

- I replaced all the gaskets with the Litetek set. Don't be put off by their location in Thailand - Super fast delivery, and very helpful with fast response for a technical query that I had

Thanks everyone for their support, will finish building it soon and go for the maiden run