Cynic

Now i dont want to overly concern you BUT. You say the gears dont work right and the kickstart idler is floating around. Unless there is something odd going on the kickstart idler should be running on the end of the layshaft, not a stub. Any chance of a pic or 2. Have a look here at csml, http://www.cmsnl.com/yamaha-ct1c-1971_model8381/partslist/A-11.html I assume the idler you are on about is item 24.

Ok, i'll admit i'm a lot better with the 175's but 120psi from a stroker aint so bad and it only went up 10 with the oil so i'd say the top end isnt where the problem lies. My 175 was performing a lot like this, got a couple of things for you to try. Take off the LH cover and with the engine running at whatever its happy to on tick over try and blast a good amount of wd or similar behind the flywheel, use one of the straw things that always gets lost, and see if it affects the idle speed. While you have the WD out soak everything carb side, the rubbers everything again monitoring the idle speed. If that makes no difference then get a glass of water and dip the crankcase/gearbox breather in it and see if you have a constant steam of bubbles, OR it tries to suck the water up. Finally check the gearbox oil i would expect it to smell of fuel if i'm right. I would bet that one of the above tests will have an effect, everything you have listed above is what you would expect for a crank seal failure. Hard to start,high idle, 4stroking (thats the spotty running at 3-5000) the backfire. If the tests above prove to have no effect then it may be a leak somewhere else but that wouldn't generally give all the stated symptoms just a select few.

Sorry what a stupid fucking question. There are plenty of motorcyclists who obey all the rules, pay their insurance etc, etc then you get idiots who flout the bloody laws and get people considerable hassle from the plods for doing nowt illegal. The village i live in has tossers riding motocrossers without any legality at all, we also had to tolerate the bloody minimoto fad too, what happens when everybody in the village gets pissed off. The have a bloody clamp down thats what. Then i and half the other perfectly legal bikers end up getting stopped every fucking time we ride into or out of the bloody village. Do the wankers that caused it? no. Does my TDR look like a motocrosser for f sake. Its not the plods that are important they are toothless tigers these days without a speed gun, you will do far more damage to the reputation of motorcyling full stop. And for that i repeat what a stupid fucking question.

1/2 to 1/4 inch, oh dear. The primary instruction for this type of problem....... Beg, borrow or steal a manual. There is no way round it a crank that badly buggerd will have wreaked havoc with seals, bearings etc. Read and digest then strip and inspect. There is nothing complicated inside aside from the crank will need to be rebuilt profesionally. But if you supply the parts thats not expensive. You dont really need any special tools bar a flywheel puller so long as you have a decent bench and thats not vital and a reasonable tool kit you will be fine. One thing is for certain though, it aint gonna run as it is.

That i very much doubt, they are as nutty as a fruit bat same as here. Back on topic, Is your bike modified at all, maybe a set of pipes. Maybe some halfwit in the past made some 'performance upgrades' or is it stock.

All true very very true.

Hmmm, car engine and bike engine's are different but its only nuts and bolts. The little end will rattle like a kids toy on the bench the important bit is if there is any vertical movement when its in place. For the cost of em if your not sure change it. Same thing goes for the big end, some side to side is ok around 1-2mm is not unusual but there should be NO vertical play whatsoever. As for the not quite last question, no the crank and big end bearings need the cases splitting. Last question. Its a 2stroke, the high wear rate of a 2 stroke engine means that they are designed with top end rebuilds in mind. Ridden hard you wont see much more than 7-8000miles maybe more if you are gentle from a piston set. If you have been kind to the old girl with good oil and let he warm up properly and such you may even get away with just a set of rings and a hone. As to which section, here/ workshop/off road ,dual purpose sort of fits all of em but dual purpose or workshop will prob get you quicker answers.

Don't forget the theiving bas##, I mean helpfull dealer will be charging something like £80 an hour for labour, add to that every nut bolt bracket and washer that isn't quite right will be replaced. You must know someone who is handy with the spanners even if you aren't and see what fixing it yourself will be. If the bodywork is only scratched then you could get a new gear lever and a rossi paint job for a lot less than 1200 quid.

Bet he's on there already, how long will the bandit last.

Er, ok. I can fix an engine fine, most mechanical things i just seem to be able to do. Like i can 'see' its insides. But puters are well past me. Whatever that link is on about fine but i still cant change the sig.

Er, its nice but they are like belly button fluff. You had a real one off with the MT especially with the mods you had made. You are going to have to work really hard to make this as individual without making it crass.

Are you on TDR250.co.uk, its another bunch of nutters with fortunately the same twisted, perverted and wholey un pc sense of humour as this lot. The site is deceptively busy not like here but you normaly get most things answerd in 24hours, less if its something juicy.

Best thing to do, post some decent photo's of the plugs. Picture paints a thousand words etc.

Don't be soft man, i just spent 5 min on e-bay and brought up no end. Just enter Yamaha 125 into the search engine and look in cars,motorcycles and vehicles. Depends what you are after.

If you pay 400 quid for a field bike you want thumping. You can get perfectly good but older DT's for around 4-500 quid that are in ok condition and need nothing to make them legal.

Wouldn't be vertical for a while

Thats cos they are getting too hot they are supposed to be NGK BR9ES's. Well mine are on a std bike and they are fine. Other than that you may be damaging them when you gap em if you are not doing it right, or there is an underlying ig/fueling fault but that is unlikely. Try the different plugs first.

Its perfectly genuine they are plenty out there, just not for the UK market. Its essentially the DTLC Chassis with the 175 motor in it. It gets some modern tweaks to the pipe and the carb but essentially its the same motor. Its sold in countries with more 'liberal' licence and emmision controls. With the updates i would have thought it would be good for more than 90kph. It is generally better to increace the size of the front sprocket by one tooth and see the effect. Primarily cos its easier but also it has less detremental effect on the overall gearing. Changing the rear sprocket is also affecting the relative ratio between the wheel and the sprocket. The front sprocket will have an effect on the gear ratio's but not with such an obvious impression. Check out the size of your front sprocket and go up one. Its probably a 14tooth jobbie at the moment with a 48 on the rear a 15 on the front will increace your speed by around 10mph/16kph depending on how strong the engine is and the headwind. If the engine is fit and well it probably wont hurt your acceleration all that much in the lower gears either but the MPG KM/L will drop off because the engine will be working harder all the time. Hope that helps.

Well from the Photo's we can see that the bike is obviously meticulously maintained (sic) so my guess would be clutch wear and if you keep at it letting it slip it will ruin the metal plates as they will warp. You need to have the clutch cover off, then you can see if the actual mechanical clutch opperating rod needs adjusting as that could be proping the clutch open slightly due to the wear in the friction plates, or ham fisted adjustment in the past. You may even get something from popping some washers in under the springs as a stop gap.(Hope the prospective purchaser isn't reading this ) It could also just as likely be worn out and need a new set of springs and plates.

Could have been your other head in the vice,

That'll teach you. You said she would never find out...............

Ha Ha found the bastard, its a DT175 all right but mechanically its the missing link as far as europe goes between the CT1 and the MX's mechanically. A european bike will be numberd 1G1-000101 on and available late 76- early78 But in the states they had this crankcase set ( which is basically the TY layout with a different stator rotor, clutch mech and top end ) from 74to76. Through the DT 175 A,B and C That screw is a slightly different take on the later MX system just a bit more OTT, all it does is stop the opperating arm coming out, tighten it up so it is just tight then back it off a quater and lock it up with the locknut. Thats it it has NOTHING to do with the clutch slip unless it has been tightend up far enough to lock the opperating arm.

I'd still like to know what it is though. OG.

Took me a second there Where you been hiding? You havent been crocked again!

Well now we have the full picture and?, i know the DT 175 line up pretty well but i'm stumped. Can't really help you without an engine number to get the proper vehicle. The twin plug head suggests v early (although they rarely had 2 plugs in em), but the cases have a later look to em. The barrel shape is also DT like. Dunno sorry.