|
|
Post by thehut on Aug 11, 2013 16:52:40 GMT 1
got my oil pump back off arrow fully serviced and looking better than when it was new. and reading his usfull info supplyed turns out iv got a thrust washer missing off my pump shaft that drives it. so new one ordered off yamaha.  |
|
|
|
Post by arrow on Aug 17, 2013 23:19:07 GMT 1
Built a pump today for a guy off here. I have never seen so much crap in the check valves!
|
|
|
|
Post by billy on Aug 18, 2013 4:12:49 GMT 1
How do you actually do it, does it require any special tools or skills etc?
|
|
|
|
Post by copper99 on Aug 18, 2013 10:38:03 GMT 1
How do you actually do it, does it require any special tools or skills etc? Oh yes....its a dark , mysterious and meticulous process ive been lucky enough to witness...i cant say any more or he'll kill me... [a href="  |http://thumbsnap.com/SVLS5hY0"] |http://thumbsnap.com/SVLS5hY0[/a] |
|
|
|
Post by icarus001 on Aug 18, 2013 14:10:36 GMT 1
Its like the Elves and the Shoemaker, he leaves them out on his table of a night time and in the morning they're all done  |
|
|
|
Post by arrow on Aug 18, 2013 19:07:33 GMT 1
Hi Billy, there is quite a bit to it. I made some tools for pushing the seals in. Its important especially with the tiny seal to use a tool just a couple of thou smaller than it. If this seal is fitted with the wrong tool it is very easily dished, this causes it to be too tight a fit on the piston causing rapid wear. The front seal is fitted after the plunger assembly is fitted, this way the side pin is not pushed through the new seal. Sometimes the main casting is scored in the bore, this reduces oil flow. I have had to tell a few people that the main casting is scrap and replace it with another one. Yamaha modified the camshaft on later pumps to prevent this from happening and I incorporate this mod on all the pumps I re-furb. Some time ago a developed a check to measure the cams for wear limit, at this time I don't know of anyone else that does this. Some camshafts are worn out of spec and others are hardly worn at all. I always de-burr the cams with a diamond tipped needle file. If the cam is worn then the pump cannot deliver the correct amount of oil at the 3/4~full throttle setting. The cams do not run in the 2T oil and therefore should be packed in grease, there is not much grease left in a 30 year old pump! Lots of pulley springs have wear on the coils (they rub together in use) if the wear is light and not concentrated in one spot then the spring is ok to use, if not I will replace it. Same with the plunger spring. The piston is resurfaced, but I only need to take off about 0.0002" (2 tenths of a thou) to do this. If the pump has been running a zero stroke for long enough the piston sometimes has a score mark and needs to be replaced. Some times the thrust washers are worn out and sometimes they are like new. The underside of the big washer normally has a heavy wear mark where it contacts the heel on the pulley, this upsets oiling at the lower rev range, I always remove the wear by lapping it off. The check valves always have some debris in them and many are passing. The steel balls can be discoloured and marked affecting the seal. I used to inspect the balls but this is not easy and takes time. I replace both balls in all the pumps as a matter of course, as well as scrubbing the hard rubber seats with a purpose made brush. All the work is done by hand, without the use of power tools. Although some stubbon screws are removed after cutting a slot in the heads with a dremel.
Someone once said (not on here) that all that is required is a couple of new seals, this is only a fraction of the oil pump re-furb service.
The complete job (uninterrupted) on an old pump takes about 3 hours of work.
HTH.
|
|
