Trying to fix an issue
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@HOTSHOT-III
Sorry bud, was actually replying to stevie
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Fuel tap rebuilt + new fuel tap installed. Weāve definitely fixed that problem.
Air boot / box has been cleaned and seal-allād and a brand new air filter installled
Put it all back together and fuel pisses out the overflow and leaks from the float bowl (i can only assume thatās my doing and Iād just forgotten to tighten up the screws adequately). Bike also wonāt Rev out past 5k (rough guess as I donāt have a working Rev gauge)
Float heights been checked and itās all in spec + float needle in perfect working order
So now what? Iām gonna get the carb back out again when I have a moment and have it fully rebuilt
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@Stevie-Wonder when the carb is next out, put your lips on the fuel inlet and blow, tilt the carb upside down and continue blowing. Confirm that the float needle shuts off the fuel.
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Also remove the brass cup that the needle valve sits in and check the o-ring condition. Make sure the neoprene rubber tip of the needle is in good shape and secure to the needle ābodyā. Also make sure the spring loaded dowel pin is moving freely...
Itās best checked with the carb off and blowing down the fuel pipe while manually closing the needle valve like Calum suggested. If it closes tight but still leaks out the bottom outlet pipe check the bowl drainage screw/stop-pin is in good order and closing without leakage...
Good luck bud. Youāll get there
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@Calum said in Trying to fix an issue:
@Stevie-Wonder when the carb is next out, put your lips on the fuel inlet and blow, tilt the carb upside down and continue blowing. Confirm that the float needle shuts off the fuel.
Iāll be doing this in 5 minutes now Iāve found some time. Must admit thought Iāve swallowed a pill and Iām giving my carb to Jim Bailey.
The pilotās jetās head is fucked as my precision screwdriver turned out to be between not precise enough.
The air screw has not been adjusted for as long as Iāve had the bike, Iāve just not needed too. Thanks to this and our british weather Iām pretty sure itās seized.Long story short Iām taking the L. I still have to use the bike to get about and itās not until I get my car/big bike license I donāt then have to rely on the bike. Which means every time Iām back at square one chasing mechanical dragons again I lose money and time I donāt necessarily have ultimately putting me further away from getting those licenses.
To be fair though, Iām not an engineer, I donāt have a ultra sonic cleaner so I think either way Iād still have needed to give it to someone else.
Thanks a lot though boys, safe to say I donāt roll my eyes at the thought of carbs anymore because of you lot
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Iāll reopen this thread again if ever the issue reoccurs and I canāt solve it, thereās a lot of useful info here.
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When my pilot jet got chewed up I used a small āsharpā cross head screwdriver, I used a small hammer and tapped it into the jet using one edge of the cross to line up with the original slot. A few light but sharp taps worked a treat!...
Also a good soak of WD40 and later a water bath in a suitable bowl with a kettle of boiling water usually loosens up stubborn threads without damaging any o~rings, ect...Let us know what the man says the problem was!...
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The message I got from Jim prior to my carb being posted back to me
āMorning mate,
I got your carb sorted 1st job today
Your fuel leaking was the float valve quite worn so fitted a new Japanese one for you.
I managed to get the air screw out ok, first one this year they're usually well seized.
Had to drill the pilot jet out though, I fitted a decent used one in there now.
Your power jet was partially blocked, tiny black deposits came out of there so maybe from a rotted bit of hose at some point in its history,
And your emulsion tube was a bit grubby so cleaned that for you, I took a picture of thatāMy reply:
ā Wicked mate beyond happy, Iāve not had a spare jet to knock out the emulsion tube so even in the past when itās been ultra sonic cleaned thatās remained in situ.The air screw I had suspicions that youād be okay with, Iād messed about with it before but since my bikes been jetted perfect since the day Iāve got it Iāve had no reason to play with it. Anytime Iād loosened it off itād come out it was just a bit of a tosser.
As for the float valve, do mean the little bit with the rubber tip? Because Iād had it out before checked the spring on it and rubber and all seemed okay (not that Iām arguing or saying youāre a lier, Iām just eager to hear what I missed so I can learn from my mistakes
)Sorry about the pilot jet too, if you could recommend a good screwdriver for pilot jets to avoid that rookie error Iād greatly appreciate it man
Also happy about the price, I thought itād be more
, one last thing as well did you put in new gaskets etc?ā
(Price was Ā£70)Jimās reply:
ā Hiya mate,
I use a mains tester screwdriver with the plastic sleeve cut off for the pilot jet it seems to fit perfectly.
The rubber on the float valve was quite worn you can see a line around it that's quite deep, I have changed that and the brass seat that it sits in.
Your carbs sat now below my Lc tank with petrol going into it so will leave all day to be sure.
I use royal mail
No gaskets needed but did replace the power jet pipe as that was a bit stiff.āLong story short apparently my float valve was the problem. Admittedly I feel like a bit of a tool for not just replacing it for the sake of it to rule that issue out but we live and we learn.
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Ā£70 sounds like a fair price, especially if parts have been replaced with Japanese. Iāve seen the ācheapā fleabay valves and the build quality is ānot goodā...
It would of been causing running problems for sure. Interesting about the power valve, never thought of clearing it through...
If the screwdriver isnāt the exact, tight fit, to the jet slots width (also diameter of jet helps!), it just lets the end-edges of the screwdriver bite into and āshiver offā bits of brass. Iāll try and find the exact size flathead size...
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@Stevie-Wonder good price that, myself and a few others advised you of the float valve a while back. And yes he's right about the screwdriver, that's what I use just have to cut the red plastic sleeve off with a Stanley knife. There's a special pilot jet screwdriver available but it's Ā£30.
https://www.ebay.co.uk/itm/374176786046?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=4ytB3dNFSrS&sssrc=2349624&ssuid=7ztfcrwyt6w&var=&widget_ver=artemis&media=COPY -
Draper do a flathead screwdriver that is perfect. The markings on it are: DRAPER 75mm x 5mm
PAT 24584The tip is 5mm wide X 1mm thick. It is also the āgo to guyā for airscrew as well as bowl drainage
Yep! The electrical screwdriver is a proper fit. There are three main sizes, I donāt know which of the three it is. Middle or biggest. Probably middle...
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Ā£70 for new jap valve, air screw to freeād up and the pilot jet drilled out with a replacement jet. Definitely not to shabby.
@markus-w i know mate, I know.
I couldāve swapped it out after inspecting it just to rule it out the question but I didnāt. Itās a lesson learnt.
Not feeling to hard about it though as either way Iād have had to give someone my carb to drill the pilot jet outAlso the pair of you are angels. Iāll be buying one of those immediately to avoid this happening again
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Good news!
No fuel leaks, bike feels a bit more powerful too however I fear that she still wonāt Rev out and through band.
I rode the bike last night after letting it warm up whilst I worked on the fazer and she revved out further then before
but felt hesitant. Not the sort of little hesitation an oil injected two stroke has when going through the band the first or second time either.Last time I had this problem the powervalve was the issue (plastic pulley was on the incorrect angle of the diamond, causing the pulley to look like itās correct whilst making your valve offset and out of alignment with your exhaust portā¦)
To deal with this Iām bring a 5mm Allen key so I can loosen the bolts and spin the pulley cover to check the valve is fully rotating. Iāll also disconnect the powervalve and set it as āpinnedā so we no if the problem ensues it rules anything powervalve related.
So on this grim cloudy yet still warm Sunday, Iām gonna get Stella the DT out and brush off the cobwebs.
Given the air box etc has been cleaned with new filter and mesh itās fair to say we can rule anything to do with that being a problem.
The carbs just been sorted out, idle screw is now responsive again and an air screw that moves freely.
could the air screw being in the wrong position cause this?Whilst the carb was out I took the Liberty of removing the Reed cage to inspect the reeds etc, theyāre all spotless and OEM. I couldnāt see anything wrong with them.
My pipes getting a little bit rusty at the neck but still has no holes in it so I can rule that out
So I guess all that leaves us with is electrics? Which funnily enough all work
Fingers crossed that when I take her out sheās a happy girl and I get to enjoy the feeling of going through powerband.
Letās just say itās been a while since I last had my fix. -
@Stevie-Wonder Glad your carb rebuild went well.
If you want to pin your PV for test purposes, cut down the shank end of an old 4mm drill bit to about 35mm; this obviously locks the pulley in the open position but can't go anywhere when you put the pulley cover back on.
I keep one of these with the tools I carry on the bike as "get you home" in the event of a PV cable breaking. Just remind yourself to remove it before reconnecting the cables/servo as I think the servo would be powerful enough to wreck its own internal gear train if you switched on the ignition with the PV locked in place like this.
Also have you ever replaced the HT lead? I had a high rpm misfire on my 1990 and it turned out to be this; took about an hour to change so the bike wasn't at operating temperature by the time I put it back together and tested it, but it was STILL noticeably faster/more responsive than before I changed it (I nearly flipped it pulling out of my driveway
).On the stock coil you can cut off the very top of the plastic case (i.e above where the actual lead fits into it), get the old lead out (it's glued in), then clean up the output and solder on the new lead for a really good connection.
Looks a bit messy as you have to tape it up afterwards and seal with silicone but in practice, usually a better option than a LBS replacement coil as these often have the wrong primary and secondary resistances for specific bikes (and BTW it's also worth measuring these).
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@HOTSHOT-III
Good idea that bud, I think I used a twig once when I was riding in a ForrestNot sure if you knew this though but one of the ignition cycles when you turn on/off the bike leave the PV in the open position instead of closed, once itās like this all youāve got to do is unplug the servo via the 4-pin plug by your radiator and you're set
As for the HT lead, nah I havenāt. I have been looking for an excuse to buy a nice new red āraceā ngk one for a while thoughā¦.
Whatās on there is an old NGK one or OEM original to the bike
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The power valve is open at default any was. Itās only when you start the bike that it āclosesā...
You could pull the plug before starting the engine...You do have the power valve set at open/flush when the engine is off donāt you?...
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@SpookDog said in Trying to fix an issue:
The power valve is open at default any was. Itās only when you start the bike that it āclosesā...
You could pull the plug before starting the engine...You do have the power valve set at open/flush when the engine is off donāt you?...
Yep, admittedly I havenāt checked but I doubt itās just magically jumped out of place since I last set it
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How long have you been having this problem? Hasnāt been since you last set up the power valve has it
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Since the first or second time I took my carb off to inspect the float valve when fuel was pissing out the overflow
I just took the bike out and Iām certain the powervalve is operating as should be and sat in the right place.
I do however have a sneaky feeling the air boot isnāt properly sealed, causing an air leak.
Iāve also found a little pin prick hole in the carb warmer hose that sends coolant into the carb.
I took the bike out for a little ride, I say little because I got less then ten minutes ago and the temp gauge was already 3/4 across the dash and climbing.
There where a couple times where the bike just shot off like a rocket whilst the valve was pinned but other then that Itād get to about 6-8k (at a guess because remember I donāt have working clocks) then struggle to go any further.
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Did you ever fix the leaky crank seal on the flywheel side, bud? Something still aināt right if youāre getting that hot. I used to have temp troubles till I sorted out my jetting. Even my bike has been running cool during the worst of the heatwaves. While there is water in the radiator anyways
Iād be looking for any air leaks. Spray on either wd40 or (I use) solvent brake/clutch/carb cleaner. The revs will lower/settle down if it temporarily blocks an air leak...
