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Discussion in 'Thumpers' started by CSMonte, Dec 8, 2008.
as stated many times in this thread, a BFH
That's for installing bearings. I have a threaded rod and the right size sockets for installing the bearings. The question was how to remove them?
I was going to try and punch them out with a hammer, but I thought someone may have a better way. I even read the book. It said take it to a place that has the special tool.
Carbide burr and dremel can reach in there and weaken the shell. Using a torch, heat it up and all that old grease will loosen it up and it will just about slide out.
installing is easy its the old shit that sucks taking out1 jajaja
I once used a handheld drill and hooked up a car battery to it so it wouldnt die on me every 5 minutes then bought a hole saw drill bit the exact size of the bushing/bearing
this was on a 36 year old cb750 swingarm bushing...
it took forever!!!!!!!!!!!!!!!!!!!!! but I installed some nice bronze bushings and thats all she wrote
I have some pics of what I used on my xr6 but man that is deep in my rebuild thread...
Anyone have tips for getting the rocker box out of the frame? It's in there pretty tight, but I really don't want to pull the motor to install one O-ring...
move it towards the carb, it should have enough space to get it out then..
or take the carb off,makes it pretty easy then
Put everything back together, engine in the frame, everything connected, valve clearance checked.
Poured a little oil through the valve cover holes to lube the top end, the rest in the frame and oil filter holder.
Kicked/rolled the bike until oil came out the bottom banjo.
Choke on, killswitch on (off? whatever, so it could start), a few kicks through with decomp lever in and then a few mighty boots.
Repeated a couple of times, with a small cough and fire each time before it came to life. Sweet.
Let it warm up for 20 seconds or so while checking for noises etc and then rode it out to begin the break in procedure.
First 800 meters all was fine...
Then the knock under acceleration started
Thought it might just need to warm up a little and had to get home anyway, so rode home, trying to listen to if/when this occurred. Didn't seem to happen on deceleration, only on acceleration at slowish speeds, although that may be because it's harder to hear over the wind at higher speeds. So that sucks.
What is this noise? Rod knock?
Have I trashed my piston cylinder do you think?
This was the same machinist that did benno's XR (that buggered the first piston) and hence the bore had a tight clearance. A factor, or irrelevant?
Where to now?
Some knocks are exactly as you say.. Rod knock..
Other common faults are:-
Cam chain tensioner.
Lay the bike on its left side. Leave like that for 10 min. Then you can remove the right engine cover without losing too much oil, nor having to drain it. Check the cam chain, the tensioner has an indicator up on the right rear side of the head - a disc with a strip in it that should normally be horizontal. If it's anything else your tensioner is not correctly adjusted or seated.
Inspect the crankcase oil filter screen, check the oil pump dowel that feeds oil to the side cover oil tube is not missing. (They can fall off during assembly and give a lot of grief.) When repacing the cover it can be held in place with a blob of grease to preclude from falling out.
Hope you get it sorted and the offending gremlin hasn't caused too much havoc.
what is it with machinists man!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
so you say its the same machinists as benno...so does that mean that he decided to do the same thing as he did to bennos wuth too tight tolerance or what?
I cant for the life of me understand why machinists are so damn stubborn...I hope to hell its not the same scenario as benno cause it was caused by using oem tolerances or ther abouts on a very nice and loose tolerance forged piston
good luck man
you did check oil flow did you? after starting you must make sure you have flow at the lower banjo, if not it could be your fault...just sayin bud
Is there a way to figure out if the rod or some bearings are fucked? There is definitely no vertical play in the rod, and the small end is fine. So the million dollar question is it the crank bearings or is the big end of the rod fucked?
The crank bearing that sits in the right case seemed fine when the cases were split, spun ok and didn't seem to have much play in it. I didn't check the left bearing since it is between the flywheel and the crank, but it spun ok?
This is a fairly new rod too I would say, Pro-X rod, probably put in 10,000km ago.
Final piece of information. When I ran it dry before this rebuild, it began making the knocking noise very similar to what it is now except at all times, idle, decelertion, acceleration. Since I've replaced almost everything else, would you think this is just a left-over fucked-up piece from the oil starvation time?
Thanks Airguitar. Cam chain tensioner was install correctly I'm pretty sure, I followed Steve's directions and after a few revolutions, the timing marks still lined up fine.
The oil dowel was worn down slightly but still there and definitely in place, as I was worried about losing it (and I used the grease trick already, thanks!).
Thanks for the help, I have a feeling that it's deeper in the guts though.
Yep same machinist, same tolerances etc. However, I don't believe that the knocking would be from this, especially not a piston slap since it is so tight...I just hope that if it is the road/bearings that it hasn't fucked the new cylinder and piston...
I triple checked the oil flow after priming it, and then again after it started. All good, definitely was getting oil to the top end. It isn't an oiling problem per se, I'm leaning towards it being the rod now.
Thanks to both of you for the help! Anyone else like to chime in too?
well I wish yuo luck man, that sucks
couple of things
did you replace the crankshaft end seal that is inside the clutch cover? maybe you are not getting oil to the crank and losing it there
are you sure the inner pipe tube that connects the pump to the inner case is put in correctly?
I think you soft seized , if you used the same tolerances that benno used first time around I think its only a matter of time man, maybe its scuffed up a bit and rattling...????
did you clean the crank bearings?
whatever it is it's going to mean open surgery
Ok so I disassembled the top end last night in a fit of activity and rage. Piston has some marks on the skirts but I'm not sure if it's just the start of it breaking in. More worryingly is the large black mark across the top... is that unburnt fuel?
The rockers and cam were covered in oil, but seem to have some marks on the faces and lobes? This should be fine right, seeing as i just replaced all rockers and the cam!
The eventual plan is to re-split the cases and check the bearings, while also getting the crank checked by a professional. I definitely heard a knocking noise, and the marks are similar to bennos so the big end might need to be replaced. I just hope I can still use this cylinder and piston. Remember I only rode a couple of km.
If not it will probably be game over, just too much money to invest.
Either way, I still can't do anything for the next few weeks as I have to finish and submit my thesis. One of the reasons I was trying to get the bike all back together was so I could ride with my Dad in the week after I finish uni, but before I start work. Just unlucky and shitty the way it's turned out.
If I replace number 18 on this drawing, what else do I NEED to replace? I have the adjuster ordered too..
Why are you replacing the sub rocker?
Just how far did you ride the bike? The cam and rockers look fine. No issue there. The piston and cylinder on the other hand do not look good for a fresh start up. I know you had the lower end apart as you replaced some transmission parts. It looks like there was some contamination that marked up the piston and cylinder. Have the piston and cylinder measured again. What size piston did you install? I'll call my machinist and ask how much clearance he would have set the cylinder to. Usually it's 3 to 4 thou. Did you oil the rings and piston or install it dry?