Tango

Have you tried Colin's idea of turning it over with the HT leads disconnected and then checking if the plugs are wet? I agree with the compression thing too.....a 125cc twin is not going to produce a lot of pressure.....or should I say large volume of air under pressure.....and to lose compression on both cylinders is also very unlikely......

So....does BiL make spark plugs then?...............just joshin' you mate..... Check the old fuse......is the fuse housing around the fuse wire itself blackened and does the ends of the remaining fuse wire look like it's melted? If so, it's had something draw a lot of current suddenly......but if the fuse wire looks like it has a small crack in it and you can only really tell it's blown by measuring it with a ohmmeter....then it could be just a stress break due to age..... One way of finding where the short is in the wiring is to replace the fuse with a nail and see where the smoke comes from.....

Is it single or twin carb? If it's a twin carb then it would be extremely unfortunate to have the same problem on both carbs..... How strong is the spark? You need a nice fat juicy spark to ignite the fuel/air mixture under compression......does the motor make any noise like it's even attempting to fire?

How the other half live mate........ Seriously though Neil.....hope you and GOG have a great time.......we'll be thinking of you when we're eating our chips on Hunny promenade.....

I've not done the new test .......but I believe there is a Hazard Perception part to the theory test.....so you'd probably benefit from practicing that also..... Good luck with it anyway Luke.....

Yeah....check the charging circuit out.....although if it was a sudden failure without any misfire before it you could be right about the fuse..... Had the Zener diode on my old Bonneville go short circuit on me when I was in the outside lane of the A2 at 70ish once......that was fun.... That took the fuse straight out.....and popped a new one as soon as it was fitted.....didn't take long to suss it out though.....and a replacement was pennies..... Looking at your reply there.....the bike would start with the new battery....but without a charge going back into it it would soon drop whilst riding....particularly with the lights on....

Anything on this page any good Zod?.....

Is there a Yamaha parts website where you can look up parts? Trouble is then that you need to know VIN changes.......hmmmm.....may need a bit of investigation. Do you have a Haynes manual for the bike?.....coz that'll have wiring diagrams in it and any changes associated with different VIN models. Wouldn't have thought that there would be too many changes for YBR's.....

Seriously though Luke......it's basically an automatic chain oiler......but you are best off using Scottoil in it.....firstly because it's been designed for use with that viscosity of oil.....and secondly because the bottles of Scottoil come with a connector doofer that make topping the reservoir up easier...... As to whether it's worth having a Scottoiler on the bike.....well, that's been debated at length on here before.......personally I think the Scottoiler is a great device.....but others will disagree.....

Cheers Stu....although that article is a few years old now..... I've read on the Triumph forum that a lot of guys go for Motul 5100.....which isn't really that expensive....£25-£35 for 5 litres....especially when I had to buy some oil to top the car up a week or 2 ago and it was £16 for 1 litre in the Shell filling station...

Erm....haven't you just had to change the clutch plates on your bike again Stu?..... Most cars have a single plate dry clutch....whereas most bikes have wet multiplate clutches.......I believe that there are additives in some car oils that will cause a bike clutch to slip. For the sake of a few extra quid once a year I think I'll stick with Bike specific oil..... OP....I'm sure semi-synthetic would be more than OK in that bike......

Hey luke, 5 miles is nowhere near enough to charge the battery. What the starter takes out of the battery will take more like 20 miles to replace. Also the engine needs a few revs to get the alternator really going......nothing massive, but 2-3000rpm. And if thebattery is really flat it could take a few more than 20 miles to get it fully charged.

Sounds worse than it was to be fair Stu.....3 screws for the Sprag Clutch cover...then withdraw the sprag clutch and starter gear....then 4 or 5 screws holding the Sprag clutch housing on......but it is all extra work when changing the clutch plates.....

Funny....but my car was in for a service and MOT today....and they've upgraded the coil packs because of misfire issues with these cars.....exactly as OP experienced on the bike.....low rev misfire...but OK when revved. £70 a pair is reasonable.....but maybe change the caps and leads as well if they aren't too expensive....just to save any possible future trouble.....prevention is better than cure......

Nice one Stu...... As you say....check the manual first as some of the finer details will alter from bike to bike. My Sprint ST had to have the Starter Sprag clutch and it's housing removed before the Clutch cover could be removed....and it needed gaskets for both the covers instead of having an oil seal.....but essentially the procedure was the same.....

Shhhhhhhhh!......he may want it all back......

Hey, good result Alan......looks like you struck pay-dirt there mate.....

Nice one Darren......lets hope the weather is OK again this year......

Hi mate....I'm not familiar with this bike.....but do you say the rear rim is 130 and it has a 180 tyre on it?....if so that could be your problem..... The tyres are designed for a particular profile that will put a specific footprint on the road.....so squeezing a larger tyre onto that rim would distort the tyre profile and alter the footprint.....so you could have a tyre that, instead of having a nice linear rounded profile from vertical to maximum lean angle, it could triangulate....so you end up with a kind of V profile......so the tyre has a small footprint in the vertical....and then drops onto the side of the V as you lean it....so you get this kind of falling sensation when you lean the bike. Always stick to the correct tyre size for the rims on the bike as they are optimized for the best footprint on both vertical and leaning..... Anyone who can remember the old Dunlop TT100 tyres will remember this falling sensation when leaning the bike over......

I was just mentioning the Helicoil Luke....they may be able to clean the existing thread with a tap....but if it's too far gone they may need to resort to Helicoiling it.....

Nice one mate....hope it gets sorted OK...... The bolt hole may need Helicoiling....but hopefully they can deal with that.....

Damn you Stu......I did all that typing and you beat me to it....... Yep....I agree with Stu......my money would go on a coil breaking down.....

Welcome to the Forum mate....... Why not introduce yourself when you get a mo...... What sort of misfire? Is it when revving high.....or when pulling from lower revs? My immediate thought is Coils/Coil Pack depending on what is fitted to your bike.........could also be fuelling....fuel injected or Carb? Give us a bit more info on the misfire and what your bike is running (Carb/FI...Aftermarket exhaust....etc) and we'll see if we can help you out......

It's been said several times above.....but I can't stress enough that the fit is MOST IMPORTANT...... A £600 lid that falls off in an accident due to poor fit is worse than a £40 lid that fits correctly and stays on...... Take the missus to a local bike shop and get her to try on as many lids as they have......or wait for the next bike show and go and try lids on there.....

His'n'hers?.....very Howard & Hilda...... Matching bikes next?......