Hi ,
I have to rebuild my crank due to issues as it seems the weight is lose or my webs are rubbing in cenak case giving silver flakes ..very fine ones and powder like lead deposition on to head and piston top area ..even my right plug is silver grey ...
I have been looking and found the part number 8G8-11681-00 but this one looks to be solid pin and the ones came in bikes in India were hollow ones .
Do we have any part number to look for hollow crank pins ? and can I use these solid ones in case I don't get hollow ones ? Any impact ?
Regards,
Pravin
wait. didnt the crank just get 'trued' on this?
Id look to get a vitos crank if you can. or just buy 2 matching pins and replace them both.
Yamaha stopped using the hollow pin
AFIK all the Yamaha crank pins supercede to the RD400 solid pin with serrated edges.
Wiseco makes a hollow pin or use Kawasaki 13035-1010-01
If you're going to replace the pin, you're going to replace the rod and big end bearing... NO?
Get a ProX kit with pin, rod, bearing and thrust washers, everything you need, all in one box.
Quote from: m in sc on September 23, 2021, 10:14:41 AM
wait. didnt the crank just get 'trued' on this?
Id look to get a vitos crank if you can. or just buy 2 matching pins and replace them both.
Yes crank was trued to zero and I installed it ... I doubt it's the crank web rubbing or lead weights rubbing somewhere ...
Am looking for pins but all are solid pins not hollow .... Wil ot be okay ?
Regards,
Pravin
Quote from: bitzz on September 23, 2021, 03:33:07 PM
Yamaha stopped using the hollow pin
AFIK all the Yamaha crank pins supercede to the RD400 solid pin with serrated edges.
Wiseco makes a hollow pin or use Kawasaki 13035-1010-01
If you're going to replace the pin, you're going to replace the rod and big end bearing... NO?
Get a ProX kit with pin, rod, bearing and thrust washers, everything you need, all in one box.
I guess the prox is best bet .... I do have 360 rods n small ends ....was planning to buy big ends n pins off ebay but the pins are like 30$ each ..
Regards,
Pravin
Pics ...how it looks ..
Missed flakes on the cloth I thin it got deleted
More pics
Did you take a close look at your crank? Are the flywheels spreading apart and rubbing on the case? What is the clearance on the rod large end where the thrust washers are? Any pics of the piston skirts and cylinder bores?
you need to take the crank out and inspect it. id still just replace it. especially if this is going to be stock pipes, it wont get stressed that much.
Quote from: 1976RD400C on September 24, 2021, 10:00:54 AM
Did you take a close look at your crank? Are the flywheels spreading apart and rubbing on the case? What is the clearance on the rod large end where the thrust washers are? Any pics of the piston skirts and cylinder bores?
There is 2to3 mm side play in rods no verticle .. I tried to check the webs and weight is they move side ways with a flat screw driver but they don't look snug fit .
I had out back the too end with new piston pin bearings ...cleaned the head n piston ..right one and am going to ride for 10 20 km and see if I still get that grey deposition on plug n heads n piston top ...if so am going to split open the engine .
If not then the rubbing has done whatever it could and that's it !!
I still have bearings sound which I need to address once I gather all parts and that time am gona open the engine as well anyways..
Don't want to spend double on engine work labor .
Cheers
Pravin
if you can move the weights, stop riding it.
Quote from: m in sc on September 24, 2021, 01:15:58 PM
if you can move the weights, stop riding it.
Agreed. And, the bearing sound is probably the grey matter getting into the races. Keep running it, and the cost of repair can go up by 3X to 5X.
Quote from: pidjones on September 24, 2021, 01:31:22 PM
Quote from: m in sc on September 24, 2021, 01:15:58 PM
if you can move the weights, stop riding it.
Agreed. And, the bearing sound is probably the grey matter getting into the races. Keep running it, and the cost of repair can go up by 3X to 5X.
Or all the dirt that is in the engine. The area around the crank bearing oil holes does not look good at all and who knows what has made it into the bottom of the motor.
true. ive seen a bearing lock up and completely fuck up a set of cases by spinning in the case. :huh:
Hmmm ok I think I need to open the engine up !!
Will keep you guys posted !
Regards,
Pravin
Quote from: m in sc on September 24, 2021, 01:15:58 PM
if you can move the weights, stop riding it.
No the weights doesn't move if I push them using a screwdriver they are flush ...neither the web moves left right nor the big end has any play ...
Regards,
Pravin
I had catastrophic failure due to the lead weights falling out and rubbing up against the connecting rod. It also damaged the crank bearing on the clutch side. The bearing spun in the case about 30 degrees. I ended up installing a new vito's crank. I got about 500 miles on it no problems.
That grey matter is a sure sign something is rubbing.
Ordered the bearings ... getting prepared to rebuild the crank in case required ...
Don't want to keep engine open here in rainy weather...
Will wait till the bearings arrive may be 2 3 weeks.
BTW one more question .. does the anti rotate pin on the bearing really required ? can I live without the pin or DOT and just use the grooved bearings ?
SKF sells good bearings in India which are grooved but don't have DOT as it was the Yamaha add on as a special order ..
Cheers,
PRavin
i wouldn't run one that isn't. but thats me.
vxb sells the correct bearings.
Thanks SC ,
Regards,
Pravin
Ok ... Update :)
got the bearings , opened up the engine again , there was a damage to labrynth and the silver power paste was coming off labrynth due to the right side of the center bearing broke n the piece was scrubbing the labrynth out :bang:
Thankfully I had also carried spare crank , used the labrynth from that crank though I want to see if the scrubbed labrynth will work as the both side lips are intact
Assembled the engine n now there is no sound ... Habe to run in n check
Used the old 278 rods n big ends as they were I'm very good shape
Cheers ,
Pravin