FZRSupport: the FZROnline Archive

So my 1989 FZR400 still won't start because of these damn carbs.

The bike will sit and sound like its about to catch when trying to start it but will never fully start. if i hold my hands over all of the carbs (no seal just lightly) the bike will start to half run but if i let go of the start button it dies immediately. So i know the air/fuel mixture is off but not sure where to change it. and once i figure that out(get it running) i need to balance the carbs which i was thinking of using this http://www.motorcycle-superstore.com/13 ... etor-tuner but some people say god things and other say bad. The video demonstration uses my exact bike so i know exactly how to do it. The carbs are jetted to 110 for the main jet.
the next weird thing is when trying to start the bike carb#1 starts shooting gas out the top all over the place(with out pods on) and not sure if something is blocked or not.

sorry about so many posts but this bike just wont work right, i had it running at one point but then it just wouldnt start again one day.

I also just learned something, I have a 1WG engine and just learned I have 3BF Carbs. My main jet screw on top has stripped and is like totally ruined and i'm not sure if i should get a new one, where to get one, or if i can fix it?
I think i found the air/fuel mixture screws(on carb boot, diaphragm side) and im not sure what the stock amount of turns are?

The default Turns (according to the Service Manual) for a basic setting of a 3BF carb is turning the mixture-screws 3,5 turns out..and from there on use a CO-Tester for better tune-up, mostly a bit less turns work better
For the jet-screws, check the Partnumber at either http://www.partilla.com or http://www.cmsnl.com and if everything stucks due to unavailability at yamaha, try a mikuni official importer as they should be able to deliver the proper jet-screws. Here in germany http://www.mikuni-topham.de would be the proper adress, but i guess in other countries there should be similar official importers for mikuni-parts which will result in much lower shipment-costs instead of ordering the jet-screws in germany ....

After all that fiddling, i didn't change the jet, it was the head of it that was messed and i just filed away the bad areas and it was okay, and now the bike actually runs again!
Except, on first start carb #1 was still shooting a bit of gas out the top.
Also, the cooling fan doesn't seem to come on at all even when hot and i'm gonna go look into that and report. Do you know if its connected to a fuse with other components? The vent hose from the transmission that is usually connected to the airbox(i think) is connected to nothing(pods) and when the bike was quite warm some smoke seemed to come out of the hose, now i'm not sure if its a seal, or just because it was hot, any ideas?

Tested my cooling fan by giving direct power, it worked, fuses looked okay, guessing its my thermostat. There is a single pin connector and a dual pin connector on the thermostat, i only have the single pin connector hooked up and the other owners screwed around with the other connector and put some other connector on that doesnt even fit and no i need to switch the connector and it "should" work. As for smoke out of crankcase breather, apparently this happens with over filling oil which I can see now that i have by about 2mm. will fix all of these.

UPDATE: Crankcase smoke is gone after removing some oil

it's not smoke from the breather, it's vapour. Oil vapour caused by the engine every which way makes the oil turn to tiny droplets. You can get a simple filter to put on the hose which should sort it out (although you'll have to clean it out from time to time), K+N do them search for a crank case breather filter

Evilchicken0 wrote:it's not smoke from the breather, it's vapour. Oil vapour caused by the engine every which way makes the oil turn to tiny droplets. You can get a simple filter to put on the hose which should sort it out (although you'll have to clean it out from time to time), K+N do them search for a crank case breather filter

Going to order one one in the next few days thanks. Does anyone happen to know the cheapest and best Carb Sync Tool I can use (maybe even make my own)? The sync pro costs so much and gauge ones seem kinda confusing

Update: Going to try these DIY tool, looks promising. Will Report.

There's no point in making your own you'll never quite trust it.
Look foe one of these, it's an Air Flow Meter for Webber carbs



You warm up the engine and then stick this into each one, noting the number that it flows. No messing about with vacuum hoses no taking the carbs off / on / off / on again and not to much money to buy. I'm checking the balance of the engine after a rebuild, as you see it's ok.