3en2 Needle help.

[dinodelta]

I have a '89 FZR400R 3EN2 japanese import and am trying to make sure everything is within standard settings before I try to fix the cold starting problem any further.

I have set the valves though they weren't more than .005 out. Clean the carbon build up off the starter commutator which was covering about 2/3s of the contacts. The inlet stubs are OK but I'll be sorting out some tooling soon to mould some new ones hopefully. The standard airbox is on. The EXUP is greased, has new bearings/seals and cables. The coils have 32000km on them so fitted a new set with leads as the resistance was a bit low and a new battery with a CX500 rectifier.

Finally, I have stripped the carbs which are the same as the FZR600. At first I thought this was a mistake as the FactoryPro website lists the needle jet as 30mm and my carbs (and the 600) have a 35mm jet. Once I checked my Japanese parts fiche for the 3EN2, the main/air/pilot jets all match what was in my carb. Also the code for the needle jet starts 3EN2 (the same as the 600 part). The american needle jet on the Factory Pro site has a code of 1WG, meaning it is a different carb (same family) because of it's dimensions.

The only thing listed on the Japanese parts fiche is the needle jet code and the jet needle/clip position. I have a 5CFZ4 needle fitted (clip position 3) and need to know if this is standard, please. I only ask as this is the needle for the 600 and I wasn't sure if it was correct. I believe the needle jet is Y-0, the same as the 600/1000.

Below are the '89 settings for the American (FZR400W/S/SUC) and Japanese FZR400R 3EN2:


American FZR400U and FZR400SUC '89

• Main Jet #87.5
• Pilot Air Jet #130
• Pilot Jet #15
• Jet Needle 5CFZ2

Japanese (import) FZR400R 3EN2 '89

• Main Jet #92.5 (Cyl #1 #4)
• Main Jet #90 (Cyl #2 #3)
• Pilot Air Jet #115
• Pilot Jet #35
• Jet Needle #Mine is running a 5CFZ4. Anyone know anything different?

[F5 Dave]

Jetting won't make too much odds if you have a cold starting problem. I suspect that the choke is the problem. Thorough clean of all jets & check flap working is first start. If it's been sitting the comp may be low with gummed rings until the bike is run for some while. If a careful squirt of engine start fixes the issue it points to the carbs. Use with care & have extinguisher handy.

[dinodelta]

Choke pads are next for renewal. No point trying to solve problems unless I know everything is as it should be. I'll just be masking a problem with a bodge. I'd just rather get the bike back to standard settings so I have a known starting point.

I can't believe that with the amount of Japanese 3en2s around no-one knows the correct carb specs. Just shows why the internet is full of postings about rough running bikes.

Got a genuine needle on order now so I'll finally know what the correct one is.

Anyone recommend where to buy the choke pads seperately, Yamaha only list the whole assembly and I'm not that rich. Apparently it's very common for the little rubber pad to harden so the choke lever doesn't seat correctly.