Emmi

Hey oldgit, There were some new valves INlet and exhaust from Israel - original made in Japan not China! When I asked about whether they were Genuine Yamaha - they said no but they are made in Japan! So anyway - my Dad went to the local small parts supplier and Yamaha wanted £70 for the Valve, £14 for the Tappet and £3 for the Nut. They also had an old Cylinder head! Minus exhaust Rocker and Cam. Dad said the Rocker and Cam were alright so we got that for £50. Anyway - head back on Valves adjusted and away she went - quiet as the proverbial mouse! Bit of a leak of Oil from the Cam Cover - when nipped up the old thread gave in - so Dad re-tapped both threads and on it went with a bit of Permatex for good measure. Absolutely brilliant now - pulls really well and gets to 60mph quite easily. Cant wait to get my Test passed... get her sold and get a bit quicker bike. Keep up with Dad then... Emmi

Ok, so I let the Oil get too low... Now I need a new/replacement Exhaust Valve and Tappet - anyone got one or where I could get one cheaper than the £60 they want off ebay? The Tappet has Mushroomed and the top of the Valve Stem is so badly damaged the split collects are proving difficult to remove... Cylinder head is currently off and waiting for parts... Emmi

As the XT shares the same engine and some of the parts from the SR you may be best advised to get a Haynes Manual and going from there. Emmi

Hi OGOAB, Doing the valves made no difference whatsoever apart from making the top end a little quieter. Inlet Valve was 0.002" out Exhaust was 0.014" out Once corrected the bike ran nicer and quiter, but the backfiring and "flamethrowing" were exactly the same. Apparently the Igniter advances the timing at higher revs, maybe it wasn't doing that on my old one so it seems to point to that. Been out tonight for 2 hours and never faulted once - deffo cured! will tootle along at 65mph. New Needle and main jet ordered to improve the flat spot. E

UPDATE: Since getting the Idling sorted when my bike runs there seems to be an erratic, inconsistent fade of power then backfiring VERY loudly! Now that she is sorted I can let you know what my Dad has done to sort out the problem; the problem being when going out on a ride from Cold. 1-2 minutes into the ride she fades and pops a bit. Then she rides cleanly at all revs/speeds for about 20-30 minutes then she starts to fade and backfire at higher revs. 10-20 minutes later she fades and backfires again - proper flames from exhaust about 6-10" out the back! This happens more and more with less time between backfiring. There is no set pattern as far as revs/speed but does it more at the higher end of the rev range doesn't matter on gear selection. But sometimes going from 55 to 10mph banging and farting like she does is a bit much... So after 3-4 weeks of time (when my Dad could) it is now finally resolved by: 1. Cleaned the Carb again - after totally dismantling it. Re-set floats, mixture and idle setting. 2. New Plug 3. New Plug Cap 4. New HT Lead 5. Checked HT Coil (primary and secondary) slightly high reading on Secondary side 12.7 Ohms instead of 7.9 Ohms - replaced 6. Checked timing 7. Re-checked and re-set Valve clearances. 8. Changed Fuel Filter 9. Proper greased all electrical connections. All of this made very little (apart from in my head) difference. 10. Changed Ignitor Unit - cannot be checked by anyone except Yamaha... FAULTY UNIT. She now runs perfectly right up to maximum revs and no more popping and farting or backfiring!!! FINALLY!!!

OK - things have progressed. Carb stripped down - turns out needle was bent - Jet barrel holes were blocked and some Petroleum Jelly was settling in the bowl despite Carb Cleaner through the Carb. Gave it all a really good clean - replaced the Needle. Calibrated the floats, re-assembled and fitted. Works like new - finally my bike idles beautifully! Thanks for your help... E

Dear All, In an ongoing quest to get my bike on the road and to sit my CBT - I cannot seem to get my "Daisy" to tick-over properly. She often seems to have an erratic tick-over - even when warm. My Dad and I work on the bike - and I am asking the question. The Idle Screw is in good condition - but there are a few flat spots on the diameter after the point on the front. Would this lead to the problems I am having adjusting the idle speed. With the Idle screw wound in full the bike revs at about 2000 rpm when winding it out it just seems to suddenly drop down to stall. Sometimes just wiggling the screw causes it to alter the speed. I cant seem to find a replacement should I need one - though I may be able to get one made up. Any help would be appreciated. Thanks!

Wow - complete with new Carb and a general clean up, checks and adjustments she Passed her MOT. Now to pass my CBT, get Insurance and Tax Disc and I'm on the road!!! Under two very watchful eyes... E

Not sure of its authenticity, but here is a link to a NEW Carburettor... looks like one for a Disc Model with remote Choke. NEW CARB E

So here goes... All the work done by my Dad... Stripped down replacement Carb. from a 1993 SR125 - not a direct replacement as the 1993 model has a Carb Heater - my 1991 does not. Sprayed it down with Carb Cleaner and de-gunked it all. Installed replacement Carb. and gave it some Choke - fired up first crank! Idle was very erratic at first - but adjustment of the idle screw saw her really settle down. Few things to do now she works... clutch seems right at the end of the release and there is almost NO more adjustment left so a new one is needed. Chain/Cover has been cleaned and adjusted to correct tension and all seems well. @bigantkl - constant searching on a number of sites and breakers - early SR125 Carbs are extremely rare!!! Eventually got one from eBay, but had to take a risk as its not a direct equivalent. Photo's to come, but when removing the old Carb. removal of the fuel pipe was what seemed like a fuel bowl full of water!! This had obviously worked its way into the Carb and basically seized everything up! Upon stripping down, the insides of the Carb was full of white powder from the Aluminium Body. I'm guessing that this had also worked its way into the Choke and seized that up! The needle was covered in corrosion as was every other screw and internal surface! The guy who had it before me obviously had no clue what he was doing! Just glad all is almost done... E

Doing it tonight - pictures will follow. E

The Assembly i.e. barrel, spindle and spring etc is the Plunger - the thing through the middle, the long thin Brass Rod - its a Spindle. E

I've now got a replacement Carb, but if I could try to explain (without pictures yet). The Manual pull-out choke; button type Carb. The Choke slider assembly inside the Carb would not budge - I sprayed Carb Cleaner and allowed it to penetrate. Removed the Rubber Gasket, Locknut but still the piston assembly would not move. the button (which is pegged with a steel rollpin) snapped off leaving the spindle and assembly inside the Carb still stuck. Once I get the Carb off again, to replace it; I will take pictures to explain as I would like to repair it to make it a spare. I can replace the spindle - I'll just get another machined up (my Father knows a few people with CNC's) but I do need to remove the Assembly... TA

That's what we thought - though cant find an early example without a Carb problem! Most other parts are readily available!!! One of the reasons we got the bike...

Hi all again, Despite a few views on my current problems no-one can offer me any advice so I'm looking for alternatives for a New/Old Carb. The newer version of my bike uses a Cable operated Choke - can I use this to replace the Button operated one without having to fit all of the related "Gubbins"? Thanks in advance Emmi

Anything that is designed to run with Oil should have Oil. If you have no Oil then chances are the engine may have seized up - if this is the case, start looking for a new engine. Emmi

Hi All, I have a Yam SR125 (1991) bought as a non-runner - guy it was bought off said he didnt use it over winter, left it outside etc... So replaced the battery - got current. Tried to clean Carb - Choke was jammed - spindle has broke and now need a new Carb. I've done lots of searching for a 2nd hand Carb with little luck - and now I've been advised a Mikuni BS26 - is this a direct replacement? Thanx - Emmi