Well that's a good read, it would be easy to say, what the hell have you been doing, but you are experimenting & learning which is admirable. Sounds like you need to get all this curiosity out of your system on a racing bike or car or kart. I've found these bikes like to run better with a stock air box, & shimming up the needles will just make it way too rich & upset the balance with all the other functions of the factory engineered carburettor. Remember factory engineers are usually older very experienced experts & they spend countless hours designing & flowing these lumps of allow in every imaginable way on machines that have been engineered to balance the internals to perfection for performance & economy. If you've got access to a dyno, go for it & you'll get it right. the other option is to race it on a track where you'll feel the difference & you'll see the improvements in lap times & you'll have a great time. But for on the road stick to the stock settings for reliability, it's always a long walk home when they break down. Check & or replace all the plug caps, they can cause grief, snip off about 10mm from the leads when the caps are off & reinstall them to eliminate another potential problem, also replace the plugs if you suspect them especially if you've been running rich with flooding carbs & settings. The new needles & seats will be a step in the right direction. Keep up the good work.
I would love to have a race bike or something that I can tinker with and not have to worry about it being my daily. It sucks at the moment because every time I mess around with the bike, it means I don't get to ride it for how ever long it takes to fix! Definitely a hard lesson to learn that a daily needs to be left alone haha. My plug caps are newish but I might snip the ends a bit (they are getting shorter all the time ha!) I replaced plugs just before I rode it. Just kinda bummed it didn't ride well. Might have to take the shims out. Thanks for the help!
Hang in there till the new needle & seats are fitted, your nearly there. A golden rule when racing is to only make one change at a time & test it or you'll never know what caused the improvement or impedance. This won't be your last bike & you'll be better educated for the next & next & next. Tinkering with something you love is the best therapy there is.
Couldn't agree with you more. Although sometimes I get angry (damn carbs!), it is definitely relaxing. Just started the bike again, cylinder 1 appears to have trouble. When revving, all pipes get very hot but on idle #1 pipe does not get hot. From memory I think that was the carb with crap needle. Dunno if its that's the connection.
So I'm at a major loss now ha! I removed the shims, replaced needles and seats, I did change float heights of a few floats that were at 20mm and they are now 13mm +-2mm, and now the bike is just acting plain weird. It took me ages to get it started, I'm guessing because the carbs weren't fueled up etc once started it ran fine, took it around the block and the engine backfiring and sputtering got worse and worse until it eventually died and then I had to push it home. Could it be my petcock just dumping fuel into the carbs and eventually flooding it? I'm at a loss as the bike seems to start off alright but then just dies in the ass and will not start again. Once I got it home I chucked a jump starter on the battery and finally got it going again but this time it was seriously misfiring and the two inner exhaust pipes were not getting hot. Btw, the new needles and seats were good quality and fit really nice, the old needles were spongy and very worn.
My fizzer would stall at 60 and splutter and ended up being my cam chain and valve shims no good think 1 exhaust wasn't even opening
I really hope it's not that ha. Things is it was running pretty well before that but I guess it's about due for valve shims and all that. Hmm I did replace the fuel filter thing with a new one, maybe it's not big enough?
Maybe it doesn't flow fast enough, after all the work on mine I couldn't ride without the carbs running out of fuel so I got a high flow one and that sorted my issue. I have found this style works the best I tried 3 different ones Got it from team moto honda
Okay that seems like worthwhile and cheap quick check. I have a smallish paper filter in there atm, I heard they were better than the brass types
Before the bike crapped itself, they were sitting at 3 and a bit turns. I changed them to 3.5 turns trying to try and get the bike to start better as the bike would only start with choke.
It did run well right before this happened. The misfire could be fouled plugs, but that still doesn't explain the crap running
I agree 3.5 might be too much, fact settings are usually 2 turns out, backfiring is fuel burn in the exhaust pipe, Could be pilots or even choke letting too much fuel through & fouling plugs & dumping unburnt fuel into the exhaust where it ignites. Your pet cock won't be the problem unless it's not opening, the new inlet needles will hold the fuel flow. Sounds like a rich problem but could be wrong Doesn't sound electrical either. When you say it likes choke to start, do you mean from cold or when she's hot?
The brass ones are good if you are prepared yo change them every few months, they filter so well they get clogged, the next best is a large paper type, but It doesn't at the moment doesn't sound like its lack of fuel. I keep wanting to ask what condition your inlet rubbers are like, if they are perished & sucking air that'll cause problems but it doesn't fit with the symptoms
I didn't think of that, last time I messed with the air screws it made the bike crap. Probably fouled up some plugs as well, I expect them to be blackened for sure. After I put the new litetek kit in, the bike would only start with choke when cold. Previously it would start without it. I guessed the choke leaned out the carbs and helped start so I assumed backing out the air screws would lean out the bike as well so I didn't have to use choke, that's why I went 3.5 turns. Inlet rubbers appear to be in good condition I remember spraying carby cleaner on them to check for leaks and they were alright. Will suss out filters later, but yeah it doesn't seem to be the culprit. Thanks guys!
When you pull the choke on it allows fuel to be sucked up from the bowl & richens up the mixture a lot. When you wind out the mixture screws it'll richen up your mixture also. It's a good sign that after you fitted the Lite tek kit you needed the choke to start it which means your getting things back to where they should be. Nearly there.
Well then I cleaned all the plugs, #2 and #3 were blackened and crap. Changed mixture screws to 2.5 turns out and whaddya know she goes like a cut snake again. Not a single cough or sputter through the revs, aaaaallllll the way out to redline much to the dismay of my neighbours haha One thing to note as well, I actioned the carb slides by hand and one of them was notchy and when the slide was held up to the highest point, the needle was loose and had movement. So I re-seated the spring and the plastic thingy on the needle and made sure the spring compressed into to housing nicely and it came up smooth with no movement of the needle. My springs are all bent and out shape, they work but I wonder if you can get new springs? Negatives- Accidentally snapped off an airbox-to-carb bolt which I'll get around to extractimg when I get the right tools, airbox is nice and firm so I'm not too fussed. Positives- I can now remove carbs from the zxr with my eyes closed and one hand tied behind my back. Also bought a ridiculously long screw driver to get to those pesky carb boot clamps. Take home advice for me- If it ain't broke, don't buggerise around with it!