[dt 175 mx year 1980 smoking]

hi and thank you for all your help i changed the o ring plus put another new crank sharf seal on then put it all back together and took it for a 5 mile ride yes i got soaking wet with the rain but i wasnt bothered in that knowing that the bike had stopped smoking like i said it was my first time on trying something like this and my blimming last but with all your help i got there in the end thank you all so much

kind regards jay

[dt 175 mx year 1980 smoking]

I've just done exactly the same as you on my 175MX and put it all back together without a problem.

(although I've stripped and rebuilt hundreds of engines in my time)

I renewed the main bearings and the gearbox bearings, all the seals and rings. Started 1st time and no smoke! other than the initial smoke on priming the oil pump.

As you're aware from the posts, oil has to remain in the gearbox and not get into the crank area.

Whilst there is no gasket between the 2 halves,

I assume you put "instant gasket" on the exposed face before reassembly. (I took photos of every stage to help others).

Plus.....

I'm also in West Sussex!!

hi thanks for the advice this engine now has stopped smoking and runs very well now ive got another dt 175 mx engine but its in bits and been split how much for you to rebuild that one i would never do it again but like ive said it was my first time and my last if you could let me no how much you would charge my mobile is 07515403879 ive got new gear selctors two new crankbearings and head gasket oil seals so on could you let me no

kind regards jay

[dt 175 mx year 1980 smoking]

yeah but until its had a decent ride say 10 miles i'll reserve judgement, it needs the long ride and to be up to temp for a while before you can say if you have a problem or not...its been off the road and under maintanance after all. I would expect it to be a bit smoky at first...thats my opinion anyway for what it's worth

thank you for your advice i will take it for a long run tomorow. i just carnt understand since ive put the o ring from the other bike on to mine like ive said i shouldnt do that, it stopped smoking on tick over and when i reved it but i will do what you all say and take it for a long run im so greatfull for your help

[dt 175 mx year 1980 smoking]

I would do what og says and give it a good run. Did you put a lot of oil on the bearings and piston and bore when you reassembled it .If so it is proably just this being burn't off after it has built up in the crankcase especially at high rpm. Just keep an eye on the gearbox oil as if it is burning it to that extent the level will drop. Have you checked the oil pump cable setting to make sure it is set right and make sure the oil pump cable hasn't pulled out of the junction box or are you using premix in the petrol tank ?.

hi yes quite a bit went down i no it was stupid of me and yes i need a rollocking for doing it. i will take it for a long ride tomorow and see how it gose and i will keep an eye on the engine level to the oil pump cable is all in contact. i just carnt understand since ive changed the o ring from the other engine it dosnt smoke on tick over or when i rev it but i will let you no tomorow how i get on im so greatfull for your help

[dt 175 mx year 1980 smoking]

yeah Tony it seals onto a spacer collar and under the collar on the crank is the 'O' ring but i just dont know why jason cant go for a ride and confirm if there is actually a problem or not! it seems its just been built and gone nowhere from whats been said so far.

sorry if ive said it rong and you didnt understand what i said i dont understand myself sometimes and its my first project right ive took the bike for a ride like you have said and belted it up the road i got it up to 60 miles an hour and by god i couldnt see a thing behind me with smoke but it has stopped smoking at tick over but before it was smoking bad on tick over it dosnt smoke when you ride slow i must point out i didnt change the o ring when i changed the crank bearing and oil seals ive got another 175 engine which has big problems and i looked on the old engine and took the o ring of i no you shouldnt but worth a try and put o ring on my engine i then put it all back together and then started engine on tick over it stopped smoking on tick over even when you rev it it dosnt smoke but dose smoke bad when riding realy bad

kind regards jay

[dt 175 mx year 1980 smoking]

Hi Jay

Does the RH oil seal lips contact on a collar or is it part of the primary gear. If you strip it again check where the seal lips contact to make sure there isn't a groove in the collar / primary gear. Tony

there is a groove in the collar thats where the o ring gose ive stripped it down again and checked it all it all looked fine put it all back together filled up with oil and started it up and there wasnt no smoke at all i was so happy reved it a little smoke but when i took it out up the road there was a lot of smoke ive just been told it could be head gasket gone

[dt 175 mx year 1980 smoking]

yeah take it for a good run before coming to any conclusions

you did remember the 'O' ring??

seals are open side in closed side out

i didnt touch a o ring the only o ring there was was a little round rubber wich fits into the stem if that makes sence but thats there and the oil seal are both open sided you can see well it looks like a round spring iver side of the oil seal i will say that looking at the oil seal one side is opened larger than the other side so the larger side gose in first towards the crank bearing sorry to be a right pain

[dt 175 mx year 1980 smoking]

jay it sounds like the crank seal on the right of the bike, When this seal passes the engine oil gets into the crankase as so gets burned producing the thick smoke, its not a full strip...not even an engine out job but you will need a clutch holding tool to hold the engine still so you can undo the nut on the primary gear altrenatively you will need to remove the cylinder piston and head and place a rod (1/2 inch drive extension bar) through the small end onto wooden blocks so the small end is approx 1/2 stroke

hi and thank you in taking the time in reading my problem

ive changed the crank seal twise now and its still doing it i havent took the bike out for a run since the crank shalf bearings and seal where replaced i just started it up from cold and lefted it on tick over do you think the bike could do with a good thrashing to clear the engine out like ive said this is my first project with doing something like this but now its bugging me is there a way of putting oils seals in, the crank shalf seal on the right hand side it gose in level to the engine casing should the seal go deeper than that i dont wont to push to hard in case i brake the seal when i pushed the seal in the bottem did go right in further than the top at first but now its level all round with the casing thank you so much for your help

kind regards jay

[dt 175 mx year 1980 smoking]

hi and thank you who helped and looked at my last problem where would i be if it wasnt for you guys willing to help

here gose im trying to do my yamaha dt 175 mx uk model year 1980 up to bring it back to its former glory when i bought the bike there was a horrible noise coming from engine i was told it was crank shalf bearing so i split the engine down and replace with new bearings and also new oil seals all round put the engine back together but now the noise has stopped but ive got loads of white/grey smoke and i mean loads, on tick over and when i rev coming out of the exhaust pipe and a bit of black oil or fuel around the back box also the engine is having problems ticking over i popped down the local bike garage where i live who i bought the crank shalf bearings and oil seals and he told me oil was getting in throught the crank shalf seal so striped engine back down like he said and renewed oil seals again put back together but still the same he told me he would do it for a cost of £550 ouch i felt what a lot of money i didnt change anything else only crank shalf bearings oil seals and head gastet it all went back quite easy and there wasnt nothing left over ive set the carb thats fine can any body help me with this twise ive stripped engine down and feel gutted before i touched the engine there wasnt no smoke and would tick over fine and run well but it was just the noise this was my first time in doing something like this but it was easy project i thought i did follow the work shop manual 100 percent of the way

thank you in taking the time in reading this

kind regards jay

[yamaha dt 175 mx trouble]

Hi Jay,

You could try the following:http://www.ebay.com/...=item5ad70476a7

Or if you want OEM try:http://www.nwvcp.com...rand/parts.aspx for the part numbers.

hi and thank you the harness on ebay ive already contacted him and he says its not for my bike and the other link you sent to me ive emailed him to see what he can do for me thanks for your help cheers

[yamaha dt 175 mx trouble]

hello to you all ive just signed up to this site as im in a little trouble an in need of some help

i bought a yamaha dt 175 mx year 1980/81 the english model. this is my first time i ever done anything like this i bought the bike to restore it back to its glory and its been going realy well engine stripped and parts all renewed new brakes new everything i wont go on but its realy gone well until it come to the wireing harness when i bought the bike of this chap he told me it got stolen by kids but when they stole the bike they cut the front of the wireing harness of the bike pehapes to get it started i dont no it wasnt recorded stolen on logbook so that was handy but ive sat down for hours upon end trying to work this wireing out but just can not do it it might sound silly to you all noing ive done everything else on the bike but when it comes to wireing im just no good ive looked on ebay but not a wireing harness for mine dose anyone have a wireing harness digram in colour for me two copie im willing to pay for the copie as if i take it to a bike shop it will cost me loads or maybe there might be someone on this site who might have one for sale i managed to get the part number of yamaha for the wireing loom the number is

4J38259040

ive tryed following the manul black and white digram in the book but no chance even with my glasses on ive got no chance i would be most greatfull if there is someone out there who would give me a helping hand with my problem if cost me well be but well be worth it in the end

kind regards

jay