Cynic

It draws air into the exhaust, this causes the unburned fuel in the exhaust to be consumed by the heat in the exhaust, lowers the nastier oxides and makes the bike cleaner for the polar bears. Only thing affected by it would be a gas analyser and as they dont do that to bikes, yet!

Bloody typical, bought the daughter a cbr125r as a step up from the scoot, yzf's were stupid money for old knackers before you ask. Throw in the need for cool points in this modern world i gave in. Yeah, Honda 125 bullet proof, can forget about it. Can still see Andy's 80k sr 125 in my head. Well guess who has a stripped out 125 needing a cam chain tensioner and a cam chain. Apparently 20k is about all you can expect from the cca and when it goes guess what it takes with it. Then to add insult to injury can you strip the flywheel with the standard 24/27internal puller we all have rolling around in the bottom of our kit box, nope its a one off internal threaded job. Same as the clutch needs a fancy locking tool too (stock plates are shite and slip, not massively but costs performance you dont have), you cannot remove the pressure plate, oh no, its a full on take the basket off job. Want to change the oil? Thats you removing the r/h crankcase to get at the strainer/filter. And to top it off the bottom of the fairing, the lugs are weak, they break, wind gets into the fairing and boom. All you have is a bikini fairing from then on. Brakes that have caliper sliding retaining pins that look designed to rust in, only accessible from one side till you drill the caliper and beat it out, (very satisfying). By the spring it will be a sweet rocket ship but im a bit fed up of fixing it in the cold. Shoulda got the yzf

No problem, nice to get results posted. Most ask for help and never say if it worked. They will bitch often enough if it doesent.

If the aux power output is switched i would use that as a trigger line and then fit the old faithful 12v relay and a fuse link off of the battery. Digging into modern wiring is not an option, no telling what is connected to what in modern canbus systems.

I would think your looking at the wrong end, the heads will fit, with a reed block that size the transfer ports will be bigger. You can see that from the change in barrel mounting bolts as the old ones, (that strip) have been deleted. You need to see what is happening at the bottom, a base gasket would help. Deck height and such is prob the same. Piston crown and combustion chamber may be different. One of those things you just have to try but very likely will fit, i would get the matching piston and head tho.

Fan of twins then. Welcome.

I have watched some of this in the past, great racing, was it on terrestrial tv or will it be highlights in a week or so, like wsb.

I think age has made the fluid spongy and that will increase the amount the fluid compresses which will in tern reduce the amount the clutch moves. That means more lever effort and lest movement within the clutch pack promoting clutch drag. My first step would be new fluid and maybe treat it to a braided hose.

Going on this image from fowlers its somewhere behind the headlight. Yamaha SRX400 (1JL0, 1985) 010 B 1985 ELECTRICAL 2 supplied next day (UK only) by Fowlers Parts

As far as the carb goes, those nasty Chinese copies (thats what they are) may work but are far more likely to cause endless headaches. Considering nothing drastic actually wears out in a carb, unless its physically damaged rebuilding is the answer.

Yep. Just one of those things that disappeared in history. I used to maintain a generator when I was younger. Old 3 cyl raf thing used for shows and carnivals on an estate. That had de compressors on each cyl. You closed them in sequence as the cylinders warmed up. Do it wrong and she would stall, then you had to try and start it half warm. Not good. The clockwork starter was also an art. Got a good sweat on winding it up even in the winter.

What you have is fine, i use the same thing. Just accept the bit of side bleed as a means to get the lines/system full of fluid. Then do the last little bit the old fashioned way. Don't forget your pulling vacuum at the bleed nipple so no air actually gets into the system its just going in the threads then out. Not up into the pipework.

Decompressors can control engine braking on a decent to stop wheels locking, or a stall. As well as making an engine very docile. The twin plugs on small bikes comes from having 2 plugs in the head, they typically have different heat ratings so the engine can be used without switching plugs all the time. Some competitive vehicles have 2 plugs for reliability, my land rover i used to compete with had external condensers, (2 off) and 2 ignition coils (coils would fail often in off road overheating covered in shite)and associated wiring. Quick swap of the king lead and i would be running again.

All the signs of a bad battery, possibly a dead cell so it has voltage but as soon as it comes under load, nothing.

Have you checked for floaters in the fuel. They can randomly block pathways in the carb and then clear. Causing your symptoms.

After 30 years... My worry will be the crank seals, costly to sort too if a rebuild on the crank is needed. Personally after 30 years, if the bike is good i would pull the motor and tear it down, the chances of it being reliable are slim at best and the cost of repairing after a massive mechanical failure on 2 strokes can be quite a surprise. At the moment its all good, set of seals and gaskets plus peace of mind when you ride it. Cheapest option by a long way.

Standard questions. Colour of the plug. Bright blue spark at the plug. Is the plug wet after repeated kicking.

Nah. Not the earth my money is battery failed internally or something close to it. Start at the battery at the very least. Losing all of the circuits which have various feeds and numerous earth paths (which the engine needs to run) says battery fault or a broken terminal/connection very close to it. The engine generates its own juice. If it was a honda you would be walking.

It stings the wallet sometimes but if a part has to be right, the next best thing to ordering from yamaha is fowlers of Bristol. A lot of their parts for older bikes is bulk bought end of line manufacturer stuff they keep in various warehouses. Won't always be the cheapest but if its a specific part, (their website parts diagrams are ace) and you want it right. People on the phone are really helpful and have good knowlege too, not the "computer says no" types.

Oh. Dofus. Yoc remember. Should say 600 fazer. No gold star for you...

I have an agreed value multi bike policy and they insure to the biggest risk. My vmax and tdr are on the same policy. 190 quid. Vmax added a 100 quid. Scandal lol. Almost more to tax than insure, that's with declared mods too. Don't forget you have doubled the fire and theft risk.

This thread is 2 years old, you need to start your own to get a fresh view. put as much info in as possible.

The at1 and the ct1 are dt's either 125 or 175, the dt designation came a little later around mid 70's but as far as it matters the same wheels, as long as its twin shock your fine.

Same for me, riding to work and he kill switch wire had touched the exhaust and melted to it. Long push for something i could fix at the side of the road, didn't even need tools as it was obvious as soon as i pulled off the lh side panel. pulled the wire off the exhaust and she lit right up.

Nope, nil points. Somebody loves it though.