axu
Newbe
Posts: 3
|
Post by axu on Jun 14, 2019 10:52:37 GMT 1
Hi!
I already made a thread in the technical part but I guess people dont read it that often.
But yeah the problem is that I bought a crank from PJME to my rd350 (1wt), and it doesnt spin freely when I close the cases, only if I apply a lot of force to it. The old crank spins freely if I put it in the case and close it. It almost seems like the webs are too big for the cases? Am I doing something wrong or is there a problem with the crank or what? Has any one else experienced something like this before?
|
|
|
Post by Tobyjugs on Jun 14, 2019 11:36:26 GMT 1
I would first speak to PJME and explain the problem to them.
You can also set both cranks next to each other and compare cranks. Measure the distance between the Webb's and measure the distance between the outer edges of the two middle mainbearings
I don't think it's possible to fit a YPVS crank in a 4LO block and vice versa. The differences should be too big.
Also post up some pictures as some forum members can spot a problem very quickly.
|
|
|
Post by 4l04ever on Jun 14, 2019 11:41:39 GMT 1
Make sure the locating pins are in the little grooves at the front of the casings, as if trapped could cause twisting to crank or casings.
|
|
|
Post by headcoats on Jun 14, 2019 11:43:10 GMT 1
Have they got little pins in the main bearings as they have to "sit" in their little slots
|
|
|
Post by dusty350 on Jun 14, 2019 11:51:00 GMT 1
All of the above. If that's all ok make sure the centre lab seal is seated in the bottom case. The crank will rock otherwise
Dusty👍
|
|
|
Post by stusco on Jun 14, 2019 12:21:29 GMT 1
When my crank came back from pjm the pins on the bearings were slightly bigger so I had to make the notches deeper
|
|
|
Post by liffy16 on Jun 14, 2019 14:16:26 GMT 1
Sounds like the crank from pjme is twisted not saying pjme do a good job but if its been dropped since balancing then it would not run true?but as said my first port of call would be to contact pjme.How was the crank delivered to you ,by courier?
|
|
|
Post by dusty350 on Jun 14, 2019 16:03:05 GMT 1
You can trim the roll pins in the bearings too - a Dremel with a cut off disc is ideal if you have one. Just be sure to keep the swarf out of the bearings. The centre lab seal needs "seating" in the middle of the case. I use a piece of soft wood as a drift and gently tap it down. Don't forget to fit the left side crank seal before you do this if it's the final fit. At this point you can hold each conrod and spin the crank - this will prove all is good in the bottom case. Dry fit the top case with all lower nuts and top bolts and check gear shaft rotation as well as crank. You can see the bearing pins and where they need to sit in this pic; 20190523_203136 by dusty miller, on Flickr And the lab seal is the ally disc in the centre of the crank. Dusty
|
|
|
Post by jackjabba on Jun 14, 2019 18:05:34 GMT 1
It sounds like its a YPVS crank. I tried one in LC cases and its just as you described. Its too wide.
|
|
|
Post by oldelsieboy on Jun 14, 2019 18:15:46 GMT 1
It sounds like its a YPVS crank. I tried one in LC cases and its just as you described. Its too wide. The OP is rebuilding a YPVS (1WT) OEB
|
|
|
Post by jon on Jun 14, 2019 18:16:30 GMT 1
Make sure the cases are completely spotless.
Jon
|
|
|
Post by jon on Jun 14, 2019 18:21:00 GMT 1
It sounds like its a YPVS crank. I tried one in LC cases and its just as you described. Its too wide. Wait for bare to chip in with his ‘wisdom’. Jon
|
|
|
Post by jon on Jun 14, 2019 18:28:02 GMT 1
It sounds like its a YPVS crank. I tried one in LC cases and its just as you described. Its too wide. The OP is rebuilding a YPVS (1WT) OEB The thread title is very deceiving being RD350LC as it’s the first thing you read and get into your head. Jon
|
|
axu
Newbe
Posts: 3
|
Post by axu on Jun 15, 2019 9:57:10 GMT 1
Thanks for your help guys, I will have to check those things when I get home after weekend. And yeah sorry for calling it LC, I am still new with these things. Atleast I ordered the right crank from pjme, not the 4L0 version. Dont know if they sent the right crank then?
When I just close the cases and try to spin it, it feels like the webs would be just a millimeter too big and they wouldnt have enough space in the casing. But all the bearings fit in the correct spots.
I will tell more after the weekend and post some pictures.
|
|
|
Post by dusty350 on Jun 15, 2019 10:13:08 GMT 1
When you say a mm too big - do you mean across the width or the height ? The webs do run very close to the side of the casing width wise. Lc cases are slightly narrower, hence the comments that a Pv crank wont fit, but as you have Pv cases that shouldn't be an issue, as long as the crank is pressed up correctly. Did you buy one of their new cranks ? I've had them before x 2, and they slot straight in - both were Lc versions though. My money's on the lab seal Dusty
|
|
|
Post by Tobyjugs on Jun 15, 2019 13:16:40 GMT 1
A 4LO crank will fit into the casings of a YPVS, but when you line up the groove up in the bearing and the engine casing for the half moon ring the pin on the outer main bearing on the other side will be slightly out and will foul the engine casings. The easiest way to identify the different cranks is by looking at the labyrinth gland. Below is YPVS gland (Ignore the black O-rings) Below is the 4LO gland
There are other difference to be found in the width of the bottom of the conrod as well. Slide a feeler guage down the side of the web and between the thrust washer of the conrod, you should have a maximum of 0.75mm.
|
|
|
Post by Tobyjugs on Jul 7, 2019 3:53:46 GMT 1
How did this story end?
|
|