mrshells

just got the motor out and i can feel some thing out of place in 1st and 4th will split the cases tomorrow

Hi today my sons 125 pro sounded like it jumped out of 4th gear while climing a steep hill at speed it now makes a rattling noise in 1st and 4th gears obviously Im gonna have to split the cases to have a look but does anyone have any pointers in any direction before I open it up ? thanks in advance also the parts catalogue list gears for 2/5 3/6 5/6 but nothing for 1st or 4th ???

now i have a better picture i can make one thanks

Thanks Andy but the bearing should be fitted into the case first then the crank pulled into the bearing by the book the case should be evenly heated to i think 200 deg and the bearing frozen then it should drop in the the crank should be drawn into the bearing if you put the bearing on the crank then beat it into the case your are actually pressing the outer in to the case using the balls between the inner and outer I have to make a puller Im getting a bit anal i admit but this little TY is very special to me

The Yamaha manual for the TY175 show a specific puller for pulling the crank into the left hand case does anyone have dimensions or a photograpgh of one it looks fairly simple to make from the line drawing in the book but it would be nice to have some measurements

Thanks again Andy Ive ordered genuine rod kit and seals today probably wont get chance to go see the crank builder in derby till next week so watch this space Ill keep you informed john

Thanks for that I have the shim sizes and I know where to put them but what i dont know is how much clearance should be and how to measure it the crank is assembled with the aid of a puller into the bearing which has allredy been fitted into the left side case. There is a shim on both sides of the crank between the crank cheek and the bearing. The crank is technically in a fixed lateral position in the left case and any expansion is all transferred to movement in and out of the right side case I can measure the inside of the cases when the crank is removed and I can measure the crank at the assembly point but what i dont know is what size clearance there should be so i can work out what size shims are neede does that make sense ?

Ive seen some bads ones as well Andy Its gotta be done again its really bad and Im really P****d off not the cost, thats insignificant really its the fact it needs doing again Im the second owner of this bike Ive known it from new its only done 1100 miles in 35 years Im quite attached to it. but when i reinstate the crank its gotta be right I have the measurements thankyou but if the new rod kit with spacers is installed and the width of the crank pressed to 55.90 min tolerance and clearance between the rod and the crank web is still .5mm (more than max ) which is more important ? getting the end float on the big end right then everything gets pulled inwards from the points end of the crank effectivly making the crank to narrow for the cases the other question is whats the best rod to use ?

Sorry Charlie the question was rhetorical My manual shows a shim on either side of the crank between the crank cheek and the bearing when installing the crank to clutch drive gear the retaining nut pulls the crank tight against the right side bearing so there is no physical movement of the crank to the left or right I have managed to find the part number for the shims but they are an obsolite part which itself is not a major problem as i can get sheet shim and make them I just dont know hwhat size to make them

having sat and read through the haynes manual on page 56 it has an exploded veiw of the crank parts 13 and 19 are shims and the manual states "as Required" but I can find no reference of a measurement that would tell me how thick the shims need to be Also looking on TYtrail UK website the parts list and diagram there does nor show or list shims ? so how does one set the endfloat on the crank when installing it ????

thanks ill give him a call wow hes a guy who knows his stuff needles to say he will be doing it thanks again

Whos a good crank builder ? not average the best ?

after extensive investigation the cranks F***** !! deflection a little end should be 0.8-1.0 mm ive got a whopping 3mm this is on a crank rebuilt by Grampians in Liverpool who have done many cranks for me in the past but not in the future !! its only had 10 hours at the most since rebuild

thanks Andy Im going to give it a good looking at in the morning Im sure it will end up being something simple but its just annoying after have sourced a piston and having the crank re built it still knocks Ive had a listen with a screwdriver stuck in my earbut I cant even narrow it down other than is does sound like top end but is cant be as its all new !!! I can see it coming off tomorrow John

Ill have a look at the carb in the morning Its not pinking its definatley a knock seriously it sounds like a diesel Im going to order an O ring kit anyway as none of them have ever been changed