Been having a bit of a problem the last few days with my bike losing power as if its not firing on all cylinders. This is only an intermittent problem but a problem none the less. Now from what i know about these things(SFA) it's either a fuel or spark problem. I found a bit of fuel in the air filter when i started to take things apart for a visual to try find out whats wrong, but thats as far as i got as i was interupted. So this would indicate not all of the fuel is getting burnt? and a loss of spark to at least one of hte cylinders on some occasions? Just wondering where i should start looking and how to go about it?
Run into a couple of problems On the outside carbs(1 and 4) on each one of the screws that hold the float bowl on have rounded, i did what i could but only made things worse. Now i've got to find someone\where willing to drill them out(i'm not too comfortable with the gear i have at home which equates to not much) unless anyone here has a better idea?. The two i got open are rather dirty. Had no problem taking the vacuum? diaphram covers off but when i did i found one of the needle thingos covered in this white junk and on another the little circlip and float thing at the end of the needle had come off. What would this do to the operation of the bike? Hopfully these two little issues(dirtyness and not connected float thingo) are the reason why she's been running like crap and sometimes running on only 3 cylinders? EDIT Anyone know how to remove the jets on these things?
Ok, whilst trying to be as optomistic as possible i'll start with the worst bit. When was the last time it had it's valve clearances checked? Fuel in the airbox, along with other crud in the airbox (?) may well be a blowback issue from intake valves being a long way out of spec and not sealing properly. This may also explain the poor performance and the feeling that it's not running on 'all four' so to speak. By all means, lets start off small... - Clean the carbs, clean them again, clean them one more time, then reassemble. - Make sure all the vacuum rubbers are in good condition with no cracks. - Set the needle circlips the same on all needles (usually middle setting, or possibly one down towards the pointy end to lean it out a little); then set idle pilot jets to 3 turns out and see how she goes. It sounds like there's a fair bit of work to do before she's purring, but best of luck to getting it all going smoothly again.
Ok the circlip coming off the needle is the cause of the bike miss firing... that cilinder is flooding... the reason why it does it some times is simpple it some times gets stuck and otheres it does not.. Poot the circlip back where it belongs (on the needle with the plastic waher and mettal washer under neath) than give it a little gentle squezze with pliers (to mae soure it bends back to it's original shape) As for cleaning the carbs... best if you use a carb cleaner and some compressed air... some WD40 helps there as well... spray and blow... it shopuld get most of the crap out... As for getting the jets out... once you have the floats out you can see a little screw right in the middle of every thing part 16 than you will be able to remove the 40 and poosh out the jet 36
Thanks for the replies, this is certainly a good learning experience <!-- s --><img src="{SMILIES_PATH}/icon_smile.gif" alt="" title="Smile" /><!-- s --> The valve clearences have never been checked in the 26k km's i've had it(its at 59500km's or there abouts) I'm going to bite the bullet and book her in to get this done, what does this usually cost to get done?
OH my god! it is quite possible they have NEVER been done!! I find that they require ajustment every 20,000km to 30,000 but I would be checking them every 10,000 km just to make soure... Acording to the manual it is ment to be done every 12,000km... on the 3LN it is a major job as the carbs and cooling sustems have to come out... as well as the ignition coils and fiew other bits... on the 2KR I think it will be easier (I have only had the chance to do the 3LNs and other biger bikes like YZF which are very similar)
On the 1000, Yamaha recommends valve adjustment every 40,000 Km's. I will be taking my engine down in Feb. to install a 6-speed, so I'll check it again an another 20,000 Km's.
LOL Honda VFR750... every 45,000km to check and the very first ajustment I did was at 80,000km!!! I heard that there are bikes where the recomended checks are every 50,000km and people never needed to do any ajustments... on the opposite scale My old man had a russinan car where the valve ajustments needed to be done every 1000km coz they would rattle themselfs silly!!
I got my valve clearences done at 22000km and thay only done 4 shims did thay rip me? The bike semes good and im on 27000km now. Should I get them cheked by another shop?
It sounds just about right... I did mine and had to do 3... how much did you pay will determine if you got riped off or not...
Some of the screws that hold the float & diaphragm cover are hard to remove as they are being seized. Spray w/ WD40 & use impact Philip screwdriver would solve the problem. I bought new bolts to replace the rounded ones though their heads are little bit bigger. As for the jets removal, I'm still on the process of removing & checking them again. I'm a little bit cautious this time as they are very fragile when unscrewing them. I'm having problem w/ my # 1 piston valve ass. though. It seems the diaphragm is not working ( no tear or holes on it) as the throttle slide is not moving when revving.
Yep, learned that the hard way. The screws seize.. Now I've got a few rooted screws. I'd suggest completely changing the bolts from phillips head to hex head or allen key head bolts, as they have a MUCH harder time being stripped. High tensile bolts are advised, too (If unsure, high tensile bolts are usually black - they're dipped in oil as part of the metal curing process). Oh, and oil your bolt thread before you screw them in.. usually helps.
WOW! TBone was saying that some ask for heaps of $$ for valve clearances because of all the crap you gotta take off to get to the valves (takes like 20 minutes.. not too hard to do yourself) That means you only got charged about $220 for labour. Cool. Oh, and as an ammendment to before: Not all high-tensile bolts are black, they can also be a yellow-slick colour (like the colour of oil or petrol on the surface of water)
I thought that you could get high strength bolts in a few different materials and surface finishes? Always just thought the high strength ones had 8.8 stamped on the head?
WOW that is a cheep price (I think I'll have to ajust mine upwards <!-- s --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt="" title="Very Happy" /><!-- s -->)... Just to check out what the local workshps charge I found that valve check/ajust on a CBR250 is about $250 to $300, YZF 600 about $600 to $800 (and there is virtualy no difference b/w them and the FZR) and of cource about $500 for the FZR250...
Some do, but not the allen key high-tensile bolts. They're usually unmarked, but are more than often black. Hex-head bolts, however, have 8.8 stamped on them I believe.. But high tensile phillips head screws are also often blank.. Ambiguity sucks.
My understanding is that all allen head bolts are high tensile compared to standard hex head bolts which are as soft as sh#t. I was told this from a nuts and bolt shop when asking for HT bolts. I think about 8 or 9. I know I have had some pressure on some 6mm allen heads and broken the hex key. Mental note " must not use 300mm of pipe for more leverage on small hex keys" <!-- s --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt="" title="Very Happy" /><!-- s -->
I got new sets of allen head bolts for my rubber intake manifolds, they where of the black variety. It’s been about 5 months and the ones on the outside of the bike have started to rust, in Canberra, guess that’s what you get for riding around with no fairings. I recon I might replace them with a plated variety next time I am in there.
