Stu's Fizzer

No the mixtures aren't perfect yet. I added half a turn last night as an experiment to each carby and she's a little rich now so I've really got to warm her up and attempt another carby tune. For the record that didn't work as the same symptoms exist. Will check the jets first to ensure I am not working with any restrictions which should prevent me for chasing my tail too much.

All the jetting etc is stock as far as I can tell, needle is in middle position etc.

Clutch is really noisy too now.. can't figure out why as that's all new as well. Seems to be very quick off the mark so it's working at least...

 

Yeh they were in oil overnight. No didn't replace any bearings. I'm sure I'll get to the clutch once I sort out this bloody carby issue heh

 

Well back at 3 1/4 turns out... still to test ride as outside is a fridge but replaced the fuel filter too as I found my spare one (original was OEM, wonder if that was contributing...?). Still a bit dumbfounded by the different noises though will have to throw up a vid at some stage for some opinions. Could be that nothing is wrong I'm just hearing things differently... but you never know with the Fizzzzzzzzzzzzzzzz

 

Ok so strange things. The EXUP valve rattle is getting worse, but I can't see that being the cause of my problem. It drives me bonkers but I'm not sure if I'll ever be able to get it out to replace the bushings either....

Still hesitant at places in the mid range especially over 10k RPM when riding hard, but if you pull the throttle harder it clears up and pulls through. Maybe I just need to replace the plugs who knows... it could be electrical I suppose. The responsiveness at idle and the low end suggests she's a bit rich though as the revs drop and then settle, and a couple of instances where I'm back at the flooding problem again and the bike cuts out or drops revs when sitting in traffic. Annoying because I thought I got past that.

It all sorta points to a carby re-tune to adjust to the new cam chain but it seems to run lean when pulling for WOT yet floods at the low end... so a bit confusing. Air leak wise I can't see an issue, it ran OK before doing all this work so unless I have a massive hole somewhere I can't see.... What flammable substance do people spray around carby boots etc to see if there are air leaks?

I'm expecting that somewhere in here I'm probably going to get the pep talk about getting new emulsion tubes and needles lol

 

Nah but I have replaced the hose previously... seemed to be OK but by the sounds of it I need to dig deeper into the carbies anyway so may as well check that at some stage as well.

Can't figure out if this thing is running lean or rich.. seems to have symptoms of both so that has me leaning towards electrical...

 

So I've been playing... Clutch looks OK





Trying to get a happy spot on how far to wind that central nut to compensate for the new plate thickness. I did the clutch a thousand or so ago, it seems OK but was a bit forceful so I'm looking to get more of a smooth application when I use the lever. I wound the adjuster at the lever all the way in, and have wound this nut in a little so the wear plate sits up against it and is against the pressure plate. The affect is hard to see without actually running the clutch.


The carbies are spotless, even though I thought I was on the middle notch I'm actually one up on all carbies.... set the pilots back to 3 turns for the moment. No apparent problems with the diaphragms etc. Am still to look at electrics, may as well check the coils and plugs while I have half the bike apart.

 

Thanks. They're not out of round to my eye...

Did you ever play with the clutch and that centre nut on the end of the shaft (inside of pressure plate)? any advice?

 

Well with all this talk on emulsion tubes in various places, here's mine. Very difficult to get a perfectly square photo with the camera over the top, this is the best I can do. I think of the first pair the one on the right is ever so slightly out of round but I think the others look OK. Any weird pixely stuff is my S3's inability to zoom in and maintain a good level of detail, up close they look OK I suppose.

I'm thinking I'll put the needles back to stock and put the pilots to 2.75 turns as a starting point, knowing these bikes have a tendency to run a little rich. I think I saw somewhere you can use suzuki diaphragms to replace the yamaha ones... tempted to do that as mine are slowly degrading (can tell by a very fine black powder in a couple of the carbies - but it could also be the slides I guess they have a bit of wear as you can see). There's not much there but it's enough to mess with things I guess.

 

So (updating all the various discussions haha) she is back together and purring like a kitten.

2.75 turns out, with all needles at stock position. Only other thing I changed was I used sikaflex to attach the air box boots to the air box itself. I don't know whether a small air leak in that area would make such a big difference on its own, but it certainly eliminated a minor hollow sound when pushing back on the throttle (ie lowering the RPM when slowing down). After a ride to and from work today she's good, very good in fact. smooth, no flooding, pulls well, very happy. There's another thread on what I did for the clutch but that's smooth now too.

The only remaining problem is halfway home I lost my headlight, dash lights and tail light. Indicators are OK, high beams work when pressing the overtake switch but neither high nor normal beams work on the main headlight switch. Checked all the fuses which are good. Great... good thing electrical troubleshooting is one of my favourite past times. I just hope it rains tomorrow so I won't feel so bad about the fact I am not riding to work...

 

Well something triggered in my head yesterday when I had a conversation with MSW about emulsion tubes and needles... it wasn't really helpful because "they're not engineers" (cop out if you ask me, if you're selling the stuff at least know a bit about it...) and he mentioned that the main jet in carbs 1 & 4 is different to 2 & 3. Why the heck did I not notice that before... 97.5mm as opposed to 100mm? I'm starting to think this could be my final issue, I'm almost certain someone has been playing before I have. Now to figure out an effective way to measure the jet size. Any ideas?

I saw stuff about someone sandpapering a coathanger to a certain width and yeh... not liking the accuracy of that idea. Maybe I need to get a new drill bit or something...

 

Interesting. I am also starting to wonder if the needles may be mixed up as well. It's not running badly and as you know from previous photos etc mine seem to have escaped massive amounts of wear. The bike runs really well generally, it's just tiny little things here and there that are off.... might have to have a play (again).