Pilot screw

[AndyK]

After not using my Fazer much last year due to injury, I had engine running problems which I attributed to a gummed up carb. Cleaning spray and redex would help a bit but not for long.

So I bit the bullet and removed the carbs to clean... I recorded how many turns out the pilot screws were (about 2.25-2.5) and put all the jets and needles etc in the ultrasonic cleaner with some cleaning fluid diluted with distilled water. All good, except I spilled some coolant on one of the spark plugs when removing the carb, which seemed to cause that plug to not spark. Replacement spark plugs and NGK connectors were fitted. Leads trimmed a bit to get fresh conductor.  Everything went back together OK.   

Next, I did the balancing using some vacuum gauges. This was a nightmare and took quite a while. It seemed I could get it pretty much on-point but then a few minutes later it'd be way off again. I iterated around and managed to get to something that was roughly consistent.

But... it sounds "wrong" like it's running on 3 cylinders when idling. Exhaust from cylinder #1 measures about 30 degrees cooler than the other three cylinders. Have tweaked the pilot screw back and forth on #1 +/- 1 turn and it hasn't made a difference.

I had an MOT this week and the guy said it sounds like the Pilot is really badly adjusted, or its a dodgy coil pack. I ordered a couple of coil packs to try - should be here next week. 

When riding on throttle it sounds better and feels like it has full power (not like it did when running on 3 with the wet plug).

Beginning to get to the end of my tether on this - If the coil packs don't fix it, I have to send it for a proper carb setup at the workshop... before I do, does anyone have any words of wisdom?

Andy
2003 FZS600 - Owned from new.

[BBROWN1664]

If you are sure you have a spark then it will be fuel/air related. Have you got the idle speed set correctly? Should be about 1250rpm

Other than that, it could be a jet that has blocked again due to debris in teh fuel line coming into the nice clean carb.

[Gnasher]

You've got what is a fairly common problem, before you do any more check inside the fuel tank for corrosion same with the fuel filter, lines and float bowls.  If you've got any of the above you need to either replace, treat or clean, if you don't the problem will just keep reoccurring, which could well be why after all your work it's playing up again. 

Balancing carbs isn't as easy as many would have you believe, it is by definition a balancing act and it's not just the butterfly's.  The air jets (pilots) must be set correctly and each carb pulling the correct level of Hg regardless whether they are balanced or not.  Then there's the TPS which is a datum, work on only one carb and shouldn't be touched unless it's been played with, again it's set by the level of Hg.  The other potential issue is the kit you're using some of the cheap sets of gauges are rubbish, then it's how you use them and adjust. 

If you search the board I've made many posts over the years, some are very detailed on how to do the job.  Top tips go slow, use good kit and make sure the tank and fuel line/s are clear of corrosion, or you'll be redoing at regular intervals



 

[AndyK]

Thanks everyone... new coil packs came today - installed and make no difference.


Started it on choke and then released choke after a few seconds. After a few minutes running exhaust header pipes were:


#1: 41 degrees C
#2:138 degrees C
#3: 142 degrees C
#4: 140 degrees C


No debris or rust in tank or filter. Next step will be to remove carb again and re-check pilot jet for blockages.

Anyone know approx cost of having a setup done by a professional with the right equipment? [/size][size=78%]  [/size]

[HydrocarbonPrimate]

Get yourself some nozzle cleaner pokey bits of various diameters, pull the carbs and poke out blocked jets, dont go mad cos you don't want to make the the holes bigger (they are soft brass) but you do want to remove any varnish, I find brake cleaner etc wont remove all the varnish that makes the tiny orrifice smaller, you can feel the difference between poking varnish crud and solid brass.


Get some brake cleaner with a straw and ideally compressed air to blow out the passages in carb body.


With the carbs off and cleaned, you can sort of "bench sync" them by getting the butterflies to be all the same, you can do it by eye but they will be miles out, you can blow through each throat with your mouth and feel the difference, then when they're on the bike they will be fairly close.  When syncing you have to be very carefull to change one thing at a time and you need to know all jets are clean and pilots set exacly the same, dont re adjust pilots untill vaccume is synced.

[unfazed]

[quote author=Garfeild link=topic=25245.msg297714#msg297714 date=1557745084]
all pilot screws to 2 1/2 turns out, as in the Haynes manual

The Yamaha manual in the download section says 2 turns.Personally, I have never had to adjust them.
[/quote]
The 2002 supplementary manual for the foxeye give 2.5 turns out. Different pilot screws on the Foxeyes

[cinek100]

Yes.Can you confirm also that fuel level on foxeye's versions should be at 3.5 mm?


Do the jets in the carburetor have size markings to make sure jets are installed that are 2002-2003 and not 98-01?

[unfazed]

Yes 3.5mm
ID mark is 5dm1 01