junker

you didnt piss on my parade jim, i was wanting an honset opinion and yopu gave yours. i argree it would be almost impossible and i would have endless things to tweak or fix, so i called sudco like the other guy advised and they told me they dont make the BS30's anymore (already knew that...) however they said they had a rack of new carbs by Keihin for around $600-$800 that would fit right in. I went to the site and looked at them the new CR-29mm's are pretty badass, they come already set up together and are brand new, and are very racing oriented. I am going this route. there is a difference of 1mm in the bore, but i think the new carbs would more than surpass my old ones even if i fixed their problems. thanks for your guys' help. My bike will be thundering the sidewalks of campus again soon!!!

Alright i haven't posted on these forums almost all summer this year, but this thread might interest some techs and serious tinkerers. i have been tinkering with my bike (my 1988 FZ-600U) the forever, rode it a few times but persistent problems need to be fixed. Mostly these are with electrical issues and with the carburetors. The electrical fixes are pretty simple - "buy new parts!" But the carbs are a bit trickier, i can't just buy new carbs because Yamaha doesn't have them anymore. And if they did, the greyed-out price in the catalogs is well over $1000USD!!! I can go on buying bits and pieces here and there for things like for example the float needle valves ($65 each, need 4 so that totals= $260... JUST FOR FLOAT VALVES) -I got on the track of the newer mikuni carbs out there. Stay with me; the FZ600 uses mikuni BS-30 round-slides. They are 30mm round slide carburetors... Many of the sites i go to sell these new, singular Mikuni TM Flat-slides, and better yet: 30mm ROUND-SLIDES too (specs indicate theat they would fit into the carb boots too)!! apparently the entire carb comes for around $100-$150, brand new (an entire carb for less than Float Valves). According to my calculations that about $400~$600 for a set of Four Brand New Carbs With No Problems... Saving me hundreds upon hundreds with no headaches. I know the carbs come individually and i would have to fabricate a bit of things, like a plate to hold them all together (which they seem to have screw holes on the carb body for...), a throttle plate connector, and a choke connector, and maybe a system for dividing the fuel to each of them. But in theory this could actually work right??? Has Anyone Dealt with these carbs? heres a link to one im looking at: http://www.jcwhitney.com/autoparts/Product...tt=needle+valve and bikebandit: http://www.bikebandit.com/product/16986

mine does the same things!!! i got an '88 fz600 and it will idle rough and rev then stay revving up at 3,000 then shoot right down to 900-1100RPM and just sit - is that what you mean by boggy? mine leaks gas too, out of the overflow tubes, like the float valves are not working, but i have disassembled the carbs several times and the flat valves seem fine. I went riding today actually because i thought it was running ok in the driveway for once, idled good after i put in the new pilot jets and revved right up, quarter mile down the road it stalled out like it was outta gas but i had a half tank, and the fuel filter was filled and downward too so gravity wasn't the issue. I have to say i would have enjoyed the walk home had i not had to drag my bulky biotch with me, and why the hell do drivers feel the need to honk at a guy in my situation? it really does not help!

steering head bolt may be really loose to, definitely check that

carb cleaner from an autozone has the tendency to break up stuff, but i notice it begins melting my plastic screwdrivers when they are laid down in it, might not be too good for a plastic tank. just a thought

also, i recently heard from someone that you can make your own gaskets out of paper and cardboard and sheet rubber and such... is this for real? and if so, that can't be mechanically sound right? I mean how would that even function properly?

I need a cheaper place than bikebandit to get a piston ringset for my 1988 FZ-600. It is a 58.5mm bore size, and it is the same engine as a yx-600 radian, FJ/Xj-600 too. any help would be greatly appreciated, any known sites with stuff like this, or a known aftermarket company that makes rings cheaper than OEM

here is a link to an older topic that may be of some use to you! http://www.yamahaclub.com/forums/index.php?showtopic=13063

i am not saying to do it, but i believe the rear shock is just a shock with two eye-holes for the bolts to go thru. I would suppose if you get the r6 or yzf shock, and use your bolts, how could it really go wrong? looking at the parts diagrams the rear shock from the r6 has a reservoir, the FZR may not have room for this bulky little thing. However it does still have 2 bolt holes, except your FZR uses this little bracket on the bottom, the R6 doesn't. R6 probably wouldnt work. a 2000 YZF-600 Thundercat has the same rear shock bolt hole bracket and config as the FZR-600, however it also has the reservoir like the R6, but the R6 has it fixed to the shock, the YZF has a hose connecting the shock and reservoir, so that will give you flexibility as to where to position this thing. It seems the res is held by a simple hose clamp to the subframe or something. The YZF rear shock would be your best bet, cheaper, better technology, and better performance than the stock FZR shock

Is there a drastic change in the bike's behavior if you get a sprocket with just 1 extra tooth in the rear, or 1 less in the front, or vice-versa? I know the bigger sprocket in the rear means acceleration and wheelies, and smaller means higher top end band, and blazing top speeds. Anything else?

repacking the muffler with fiberglass packing bought from almost any motorcycle shop ($3-$20), or even using steel-wool pads ($0.60-$4) if your really in a bind, this will restore the old muffler to the factory noise level, unless there is something internally wrong with the bike.

the top end would be responsible for no compression, but buying a complete new head may be a bit overkill! and plus if you are buying a used one, hich you probably are, you are getting into a whole nother can of whoop-ass on your wallet! who says that the "new"one is perfect? it likely has the same problem yours has Bad compression means: A) that your piston rings in your cylinder head is not sealing correctly to the cylinder walls a valve is whacky and staying open or something... or is broken off (but it wouldn't run) C)you have a gigantic leak in your head gasket and/or heads (which you would see) I listed them in order of probability btw The 90% chance cause of the problem is A! And good news: a hone and new ringset is way cheaper than your "new" top-end! Obviously getting to the root of the problem and narrowing it down to a specific issue is the first order of action... so did the mechanic who told you it is broken tell you if he saw anything that made it break??? info: The seal is to prevent the air/fuel mix (pre or post-igniton) from spraying down into your crankcase, right past your pistons (blow-by). When a ring slides up and down, it is snug against your cylinder wall, and scrapes it, your oil is splashed up by your crankshaft onto the piston to further help lubricate this scraping (for less wear) and further SEAL the rings. Now over time this scraping eventually wears the rings down, by nature. If your motor has not undergone a restoration since the day it was built, then your rings are probably thin strands of steel and are not sealing. Also, Yamaha likes to make the heads and cases out of aluminum, which is awesome for lightweight but when it gets too hot, it tends to actually warp and distort its shape (it is a soft metal, screwdrivers will gouge it). FZR's were raced, alot! especially 400's Racing means cornering with low gears and high rev's, therefore high temperatures, therefore probable warping. Thin Rings + Out Of shape Cylinder Bores = no compression Solution= hone cylinders bores and replace rings. It is a fairly do-able task if you have time and a place to rent tools from, or just go and get a price from a shop. Or maybe make a deal where if you disassemble the motor and just bring him the head and piston crowns (cuts a bunch off of labor costs) one thing that has me confused is the extreme amount of compression in that 4th cylinder. It almost seems like all the other three decided to take a load off and dump into that cylinder... but that's almost impossible

Yea but its only 1000cc, not above. the new busa is like 1400 or something and the ZX-14R is well, 1400cc. A Fireblade Liter might not really stand up against them... Its like if Honda or Yamaha took an R1 or a CBR1000 and added an FZR-400 engine on top of that

I know where the issue is. There is a bare, black insulated wire dangling in the vicinity. It seems someone had stripped it and forgot to finish connecting it. I am going to put in a slide connect and a ring terminal at the end and ground it to the bolt that the battery ground goes to. This is ok right, won't mess with the battery? SO... I have tuned my carburetors! Finally! I used a vacuum pressure gauge. I didn't buy the $100+ Carb-tune because honestly i don't see the point in buying an expensive tool i will only use very rarely. Also, there is very few bike shops here in the catskills, and the ones that do exist are for harleys only... they really hate "rice-burners" anyway, i played with the adjusters until i got all of the carbs to read the same vacuum pressure range (bounces from 0-5 Hg) and instead of sounding like a new engine, my baby sounds like a cat that needs to get a hairball out. Honestly it seemed better when it was out of balance! The Idle is super-rough, it spits and sputters when i touch the throttle, and response sucks... The tach is all over the place at a steady throttle opening too! what did i do wrong?

hi dave! how ya doin? are your from Ireland?