Actually Mr Grey could try to fit the 3LN6 slides into the 3LN1 slide housings, but it might be very difficult to source those parts separately anyway. Also from memory the 3LN6-7 might have a different cutaway on the slide. The easiest option is just to buy those new kits for the 3LN1 carbs.
As per our PM ruckusman, I think the best way to go would be to replace the needles and tubes, and then fit a washer and spring like what the zeal has:
Hey Glenn what do you mean by "chugging" problem? I've struggled to get my bike absolutely perfect, but it's still rideable. I started with some flooding problems and some strange things through the rev range but was able to resolve them... unfortunately a new cam chain has put everything out of whack slightly again and I'm back to square 1. I love carby tuning heh... My needles all look like this, and from what I can tell they all have pretty even wear.
@ruckusman Hi Glenn Glad to see you back on the scene .... bad luck with the bikes though Id say buying the kits with the tubes and needles would be the easiest .... not cheap though , but we just couldnt find any other source for them Theres some info here with carbys etc ..... the collar on the output shaft is different from the 3LN1 to the 3 onwards ... which in turn creates a 'longer' shaft needing the special 'thicker' sprocket for the later models ...... one of the best in the Litetek range of products http://2fiftycc.com/index.php?threa...ork-frame-engine-carburetors.3469/#post-39597 http://2fiftycc.com/index.php?threads/c-shaft-sprocket-for-fzr-3ln3-5-6-7-zeal.3220/ Id like to see pics of the Fizzer shaft damage Social media hype
Hiya Joker, I haven't had my carbs apart in a long time, hopefully Grey can chime in and give you the skinny on the condition of your needles. What I mean by chugging is that at random times when coming to a stop, usually at lights just when I'd lane split all the way to the front, the damn thing wouldn't rev, it would just sit there and labour, below the usual idle speed, running rich, even with the throttle full open. Letting the throttle close would usually cause it to stall. I incorrectly misdiagnosed this as being float level, fuel height problems. This could continue for minutes and would cure itself almost as suddenly as it appeared, if this sounds like something you're experiencing the solution seems to be replacing both the needles and emulsion tubes, though I'm yet to do that myself as I've only just learned about that solution.
Interesting. No mine is pretty consistent, nothing "mysterious" so to speak. It runs rich, it floods. It runs lean, it plays up. It's finding the happy point that is the fun part. I've been holding off new tubes/needles for a while because I believe there is built in compensation in the form of notches/pilot screws etc to compensate for wear such as this. Simply replacing everything may be a "quick fix" but it doesn't help me learn to tune things properly and it's pretty expensive. For a bike like this I'm not looking at pouring money into it, there are some niggles I can live with I suppose. With that said, if there is significant wear on one side of the needle, as has probably been experienced by others then that's a different story. I was able to get my bike happy for a while I've just taken a few steps backwards with some adjustments I have made.. domino affect and all that. Bit annoying but such is life.
Hey guys that's a long thread, can someone give me a synopsis? Mine wasn't the only 3ln1 to blow a shaft because of the sprocket? Will the new sprockets that you have fit onto a 3ln1 shaft at all, or is the 3ln3 shaft physically longer?
The 3LN3 shaft is longer, the proper sprocket for it will be too thick for the splined legth of the 3LN1 shaft, I think.
As Ive already explained above its the collar that sits behind the sprocket that is different .... this creates a 'short' spline on the 3LN1 and a 'long' spline on the 3LN3+ If you use the sprocket thats available everywhere online for an FZR250 3LN then it will only fit the 3LN1 ..... there is only 1 Yamaha part number as well .... you need a thicker sprocket for the later models (or use a spacer , which I consider a poor solution)
thanks Grey, I did actually read the whole nine pages of the thread and understand completely now Now I'm hoping to get my hands on a 3ln3 or higher shaft
Yea Ive no idea if the setup around the shaft etc is compatible between engines .... there was obvious changes such as internal to external filters , oil level to oil pressure sensors but how much else was changed in the newer motors I dont know Replacing the needles and needle jets is not a 'quick fix' for early 3LN carbs .... its fixing a worn part that was obviously a design 'fault' as shown by the newer BDST needle setup. My bike still has exactly the same running problems as @ruckusman as I have still not replaced mine as they are waiting patiently on the bench. The same symptoms were resolved on @Grasshopper and @Linkin FZRs by replacing them as well...... its a waste of time trying to compensate with the other settings.... been there done that. And they need to be inspected by more than the naked eye .... stick them under magnification and u might be unpleasantly surprised. http://www.factorypro.com/tech/needle_jet_wear.html
Have you measured those spacers Grey? The shaft is different according to the parts book and the spacer is the same across all models. But as you have pointed out already the parts book only shows one sprocket, 1YL-17460-00 for the later models, and we know that the 3LN1 uses the thinner sprocket, so parts books are not always correct. Someone will have to measure those spacers at some stage to clear that up. Looks like the shaft is the longer item to me.
Im pretty sure I measured it all back then when we originally went thru this stuff .... eventually I can do some accurate measuring when theres a 3LN3+ having a sprocket change here ... I have plenty of loose 3LN1 engines Maybe its a combination of things including different splines
Like anything there's a certain point of no return on wear parts where they just need to be replaced - but up until that point there are often ways to compensate that are in built into the design. My point is that although I agree that replacing a substantially worn part is necessary, replacing a part just because it has some wear is probably a "quick fix". But everyone is entitled to manage it how they see fit I guess.
Well, been some time. But finally received the Keyster kits. Suppose they were hold back at the customs... :-( But, replaced the float valve needles, the jet needle and tube and since I was on the job, the mixture screw. This together with Blairs gasket kit. After all of this drama, with adjusting fuel levels, removing and installing those carbs over and over again, it is needles to say that I was very very nervous with the start up. First she hesitated a little, but after some nice words from me to her, she started to run nice. Let her warm up and took her for a spin outside, with just the tank attached. Drove around for about 10 minutes and she drove fine. Pffffffoei. Since it was easy accesable, I checked fuel level and synchronised the carburators. I will build the entire bike up today and try to make an longer drive this evening. Lets hope: job well done.
I like what I am hearing, my carb kits just arrived, yet to fit them however as I have the sprocket countershaft to replace beforehand those carbs look nice and shiny clean, what's the fuel height set to on the 3ln3?
That is a good one. I don't know. Drove the bike this evening, she is running, but not as it should be. Cold start does need little choke and if it is me, I think she is a little too rich. I cannot rev easely in neutral and when accelerating, the engine is bogging after shifting gears. Driving below 12.000 rpm is going fine, but driving some time above 12.000 rpms is going worse after a time. I did nothing with the jet size, just changed needle valve, needle and tube. Hmm, should it be the fuel level? Perhaps I should bent the floats back to before, but than she is getting richer??
Are the jets all clear? Exup working correctly? http://2fiftycc.com/index.php?threa...-powervalve-information-and-maintenance.1099/