Dirty_Andres

Bike has now passed its MOT!!!!!! YAY!!!!! Absolutely chuffed, everything's working peachy, only problem is that the crank-case halves seem to be leaking a very small ammount of oil. I doubt it's the breather tube being blocked. Tried torqing some of the screws down, but the metal's too old and it's getting chewed up by the impact driver. Anyone have any ideas on how to stop it? So far I'm thinking, undo the relevant screw/bolts and replace them, then torque the buggers down. Does that sound reasonable? Not 100% sure where it's leaking oil from

Ok, if you want to sell it, I would recommend stripping the bugger to pieces and selling them individually, that or sell it as spares or repairs on ebay, that way you can shift it in one go. Otherwise, find out what the hell went wrong and fix it. As long as it's just the engine, you should be able to - at a stretch get ahold of a new engine, then you can just swap them over and fix the old one in your spare time. What is actually wrong with it?

According to the Haynes book of lies, you're supposed to remove the cams by threading a bolt into their shafts and then pull them both out. I've found that this doesn't work, as I don't have a blow torch and I don't have any tools that will do the job. Best bet is to take it to a garage and have them heat up the head a little bit, or if you have your own oven, then heat it up a little and yank the buggers out! Hope this helps.

Update! Hello all, so here goes the hopefully last update to this page. Polo has been sold, I now have some skittles. Bolt was a peice of shit, so I got a flywheel puller and changed the cams. Started up engine and still had the same old problem, finally got around to buying some new jets. Adjusted float height properly and installed new jets. Cranked engine over, would only run with the choke on. Cleaned carb about a million times, still would not run properly. Checked fuel, filter, full of crap, checked air filter POS!!!! Ordered carb from scrappie, ordered new air filter. Cleaned and installed carb from scrappies, took out airbox, cut that ugly useless thing off with a dremel, installed air filter. VROOOM!!!!!! Rejoiced. Currently waiting on in-line fuel filter, just to make sure there's no more crap going into the carb. Bike is running sweet as!!! I'm so happy, but so tired, spent last 4 days trying to get the old carb working with a "repair kit", which it turns out had the wrong bloody jets in it. Useless shop monkeys. So yeah, all that's needing done now is for me to fix the ugly plastic fairing that holds the headlight in place, seeing as how it's broken again and she'll be up for her MOT. If anyone has one of the newer yamaha sr125 speedos and headlight sets then please pleaase get in touch. YAY!

Update! I've just got a 16 mil bolt in today(to take off the flywheel), waiting on my mate to turn up so that we can put on a new cam chain It just looks like the cam chains haven't been adjusted at all in the past, gah! How can people even get away with neglecting these machines so badly?! I'll let you know how things work out, bit skint at the mo, so it may be a while till I get my bike MOT'd and taxed. Ps. Anyone wanting to buy a 97 VW polo with a years MOT in scotland, send me a PM, can offer a decent price.

Hey mate, cheers for the quick reply. On the first engine I had to jam the sprocket with a alan socket.....not the best way of doing things. Seeing as how the engine is about as old as the last one, I may as well change out the timing chain guides, if they're worn it may well have let the chain wobble and grind off some metal......any thoughts?

Hello all. I bought my SR125 last summer as a project bike and have yet to get it running properly. To get you up to date on what' shappening here's a bit of a chronology. Last year, bought the bike, front tyre flat, drums seized up, carb stuck open, crank flooded with petrol, indicators acting out. In between, sorting out all that crap, dismantling, cleaning and reassembling the carb about a million times trying to figure out why on earth the engine wouldn't run without the throttle in all the way, then running really fast and dropping of rapidly to barely ticking over then dying. Last month, took the top end off, cleaned out the gunk, polished piston head, reassembled it all with new gaskets, checked valve clearances, changed spark plug for correct type(read the manual, duh!) started engine, rejoiced. Engine running sweet as, hardly any problems with idling. The day after, started engine up went to adjust carb, revved engine a wee bit and PLINK! Both rocker arms snapped at same point in same way, piston now has a lovely little stamping on it from where it whacked the valve, I'm assuming that it was the timing chain jumping, lots of white smoke before this happened. Checked head, loads of oil, so not a lubrication problem. This week, finally got around to buying a new engine, swapped over starter motor from old eninge(this one didn't come with one) adjusted valve clearances(very fiddly, seems almost suspiciously hard to get it right and yes I'm using feeler gagues), timing is out by a bit so will need to take the chain off and stick it on the sprockets properly(waiting on a flywheel puller to do that) with the timing marks all lined up. How do you split the cam chain? I've been looking for a link and can't find one, oh and how do you split the drive chain once the pin is on it? Can get it on, but not off!! And now for the strange bit: Both engines are from the same year ('89 as far as I can tell), so this may be an issue of the engine's manufacturing run. On inspecting the cam chain on both engines, I've noticed that the sprocket end of the cam tunnel used to have a lip, I know this because I can see what's left of it on the old engine, however the new engine has none left, as it's been completely ground off by the cam chain, the old engine isn't so bad. As you can imagine this is quite shocking, but my mind's been put to rest as I almost had a fit when I looked at the new engine's oil filter and saw that it was full of little bits of metal!!!!! It would appear that the timing chains in these engines have been either slack and running for some time, or even worse that the camshaft's bearing is slightly on the wobbly side of things. So anyway, i have now ordered a new cam chain to fit into the newer engine, as it seems that it's got the same problem aswell as the timing being off. I'm actually quite tempted to take the top end off to make sure that everything's ok. Ah, and by the way how the hell do you guys get the cam sprocket off? I've been doing it according to the haynes book of lies and on the old engine the cam chain slipped and I don't want to go damaging anything. I'm hoping that the flywheel/clutch holder will let me undo that bolt more easily. So yeah, quite a lot of time and money being gobbled up over the last year, if anyone has any idea as to how the cam chain could get so out of hand, then I would like to hear it. Ta.

Sounds like your crankcase pressure relief valve may be stuck open, either that or there's too much oil in the crankcase, causing excess pressure(hence the oil being blown out into the air box). Check the oil level with the engine cold, if it's been running it takes a bit for the oil to drain back down from the head. If the airbox is filling up with oil, then the pressure release valve may be jammed open with gunk, thus resulting in oil being blown off into the air box(instead of excess gasses/pressure in the crankcase). If it's the latter then it may be a bit complicated for you to take the engine apart. I would recommend running it for a while(check the consistency of your oil, it tells you more than you would think about the condition of your engine). Should you find any water floating around, or gunk then it would be reasonable to assume that your engine is needing cleaned out. Try running it for a while and changing the oil real regular and see if it goes away(hopefully the fresh oil will get rid of all the crap clogging up the valve), if you're lucky that should save you having to take the blighter apart . If in doubt buy yourself a Haynes manual, they may be expensive, but they're worth every penny. Good luck mate!

Hey mate, I bought the SR off of ebay. Some fucknut decided to flood the engine with petrol and leave it sitting for about 7 years!!!!! So when I changed the oil I got a lovely surprise(oil filter was totally fucked, and the gauze was full of crap). I'm going to check the valve clearances and the cam chain, as it may be them. Mileage is in the 12.000's, and seeing as how the last owners decided to flood the crankcase with petrol, I wouldn't be entirely surprised to find the bearings knackered. I got some bearings for 5 quid off of wemoto, looks like I'm going to need some gaskets, but for now I'm skint and awaiting some circlip pliers so I can replace my fork seals. A new engine isn't a bad idea, I bid on one on ebay but unfortunately had to withdraw, as I discovered to much dismay that I'm skint! Well at least untill the end of the month Oh well, at least I've got a Haynes manual... I'm located in scotland. Cheers

****UPDATE**** I checked the spark plug gap and it was way off, engine starts fine now, the only problem I have now is that the wonderful left/right hand side crank bearings are rumbling....bwah! So it looks like a bottom end overhaul for me.... Oh well at least I'll get to know the intimate workings of my motor If anyone here has ANY advice on how to best take her apart and put her back together properly then please let me know. Cheers!

Hey everyone, I've just recently bought a 91 custom and have taken the entire last week getting it sorted, and I'm now really needing help in getting the bugger to start! My mate came round the other day and got it running(I'd previously taken the carb off for cleaning, so all the jets were and still are nice and clean, and the right type), although it would cut out when idling(he reckoned it was just flooding), so I took the carb off, checked the jets again, adjusted the float (by using an array of different measuring devices, including a tread depth guage) height and put it all back together. I think I should also add that I fully cleaned the air filter before all this aswell.... He also told me to charge the battery, so I did and today I killed the battery trying to start it(would just keep on chugging slower and slower untill the solenoid buzzed), so It's back on the charger just now. Stupidly enough, I checked the throttle stop screw and the vaccum take-off plug to make sure they were ok and forgot to write down how far in or out they were! ARG!!! Since then when trying to start my bike for the past two days, nothing has happened. The compression is fine, the engine is turning over and there is a spark, yet my engine is failing to start I can't make my mind up as to wether the engine is flooding, or just not getting enough petrol, as I tried turning off the fuel tap and adding a couple of drops of fuel directly into the cylinder, then starting it, but it still wouldn't start(yes the spark is jumping 6 mils or so) So I think that I've maladjusted the vacuum take off plug, the throttle stop screw and the float height and i don't have any tubing around with which to externally check the fuel height. What part of the bottom of the float are you supposed to measure(as it's curved) and when it says gasket face, does it mean the surface where the gasket lies or the lip around it? What settings are you supposed to have the throttle stop screw and vacuum take off plug(I replaced the sealing washer with an O ring, will it cause induction leaks?) ? What is the best method of measuring and setting your float height? Cheers!