advice needed connection rod

waycrazy

New member
I had a small knocking noise that was real prevalent at the clutch cover. So I pulled the engine. I needed to check my top end anyways. I think I found out were the knocking was coming from. The cerclip was missing at the front of the clutch basket. I checked the connecting rod end play and it is right at 1.00mm which is the end of the tolerance range. I am thinking I should split the cases and rebuild the bottom end. But I am broke and not liking the idea of spending $200+ on parts . On the other hand I wouldn't like to blow things apart because I didnt. What do all you smart people think?
 
I had a small knocking noise that was real prevalent at the clutch cover. So I pulled the engine. I needed to check my top end anyways. I think I found out were the knocking was coming from. The cerclip was missing at the front of the clutch basket. I checked the connecting rod end play and it is right at 1.00mm which is the end of the tolerance range. I am thinking I should split the cases and rebuild the bottom end. But I am broke and not liking the idea of spending $200+ on parts . On the other hand I wouldn't like to blow things apart because I didnt. What do all you smart people think?
Might as well split the cases, and take the XRpiggy out and play. After the 2t engine is repaired...Your Gasser will REALLY feel light as a feather. My Thought...Finish the teardown.
 
Do you have any up and down play in the rod? Does it rock substantially? Does the crank itself have any up and down play? How man hours on the bottom end?

I think you answered it yourself though. You're at the outer limit of tolerance so its time to fix it up. The only problem is that its hard to do on a budget if you want to do it right. BUT.. it'll cost even more if it lets go and wipes everything else out.
 
Squirt some WD40 in the big end to flush the oil out of the bearing. Now check it carefully for up/down play. Side to side means nothing unless it's significantly over the factory limit. The big end play will indicate if you need to split the cases. If the bore is good you only need a piston and gaskets.
 
Squirt some WD40 in the big end to flush the oil out of the bearing. Now check it carefully for up/down play. Side to side means nothing unless it's significantly over the factory limit. The big end play will indicate if you need to split the cases. If the bore is good you only need a piston and gaskets.

Yeah but you could argue that if you're spending the time and money on gaskets and crank rebuild that you might as well change the bearings and seals at the same time. I guess if you don't have the money it makes it easier to decide.
 
Well you guys gave me the confirmation I was needing. Lucky enough as bowhunter has said I have other bikes. I am going to tear it down. It will be my first for a bottom end rebuild so I am sure to have questions later. There are a lot of hours on this old girl couldnt tell you how many. So the bike gods say it shall be done.:D Any bets to how fast I can waste a clutch on a CRF450r? It doesnt like the woods as much as the gasser.
Thanks for every ones advise its appreciated.
 
Well you guys gave me the confirmation I was needing. Lucky enough as bowhunter has said I have other bikes. I am going to tear it down. It will be my first for a bottom end rebuild so I am sure to have questions later. There are a lot of hours on this old girl couldnt tell you how many. So the bike gods say it shall be done.:D Any bets to how fast I can waste a clutch on a CRF450r? It doesnt like the woods as much as the gasser.
Thanks for every ones advise its appreciated.

I just tackled my first bottom end myself. Had my fair share of moments, but got through it relatively unscathed. If you have a wide mechanical skill set and some decent tooling you'll probably find it all quite easy. Most of my challenges either came from having a) the wrong information, b) the wrong tools, or c) lack of finess in technique from first timers experience.
 
Just take your time and take lots of photos you can refer back to when you put it together. I have done 4 bottom ends, all 2 strokes and every one of them i forgot to line the crank at TDC to the counter weight.
 
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I have gotten real fond of taking pictures of the disassemble . Thats very good advise. I have to order a flywheel puller other then that I have the required tools. Mechanical skill ??? Well plenty in automotive and farm equipment but not as much in the two wheeled world . I have done plenty of top ends 2 and 4 strokes but haven't done any transmissions. Cant be to much different from a tractor trans. Just smaller right?:D I will watch out for the TDC alignment. And Jakobi I saw your thread on your rebuild. Nice work BTW.
 
What do you mean regarding the counter weight? It slides onto a key on the shaft. I can't see how it would end up in the wrong position relevant to the rod and piston?

Automotive and farm is mechanical skills. I'm an office worker/IT geek. I do my own servicing on the bike and car, but basically everything has been self taught and only really in the last few years that I've actually taken any real interest in it.
 
I'm an office worker/IT geek. I do my own servicing on the bike and car, but basically everything has been self taught and only really in the last few years that I've actually taken any real interest in it.
It's amazing how saving money will improve the desire to service one's own vehicles. Personally, I hate spinning my own wrenches, BUT the costs are kept so low that I just do it to save the money.
 
For me its not so much the $$ or the time but the convenience, understanding and knowledge that comes with it. Living where I do means that if I take the car/bike to the shop I need to spend time doing that. Around 30mins travel, then once its there I need to pass time while someone else (most likely an apprentice who knows about as much as me) works on my belongings at premium price. They also usually take a good couple hours which I have to walk around and do things or arrange for another mate to run me around. In the end its just easier to buy what I need (even if that includes tools) and do the job myself. The coins you save also help out, but usually just get spent elsewhere (on more parts or tools).
 
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