Joined Nov 2012
2K Posts | 821+
Iceland
Hi all,
So I probably have one of the 70-degree bikes that encounter premature big-end failure. The signs so far are metal sludge + thin metal fragments in the oil screen. Plus a knocking/cattering sound.
At this stage I there are some gaps in my knowledge about tools, and what parts to replace.
I'm reasonably handy and have a decent mechanical intuition, but I'm pretty green in the motor rebuilding department. I'll have some of the finest advisors on the project I could possibly have ...
First is my grandfather who was a Citroën mechanic in the '50s/'60s, specially trained in the crazy French hydraulics they used to have in Citroën cars. He used to align crankshafts by hand with copper mallets and built his own valve cutting gear out of scrap. Great, great man. Always willing to help everybody and share what he knows. I'll be working in his aircraft hangar, next to the airplane he built - a 215kg two-seater with motor modifications, and aluminium wing tanks he welded himself. 215kg for an entire airplane, meters long and meters of wingspan! And I thought 'Bergs were light! It's like a crazy bird skeleton or steel spiderweb, wrapped tauuuu-ut in doped nylon canvas. The construction is fascinating, and then you can climb into it and fly in the air to boot. So good. I'll be sure to post some pics of it.
And then secondly I'll get some great help from some local experts who have graciously offered to drop by and help me figure things out, at least if I can scrounge up a cup of decent coffee for 'em.
And then you guys
I'm going to try to do everything myself except for pressing/aligning the crank. Will take this to a well-respected local privateer mechanic.
I have a basic set of tools - most wrenches/heads you'd need and some decent torque wrenches that cover 6-200 Nm or so. Impact screwdriver, old-school calipers, feeler gauge.
I'm going to get a dead blow hammer and a magnet-on-a-stick. I'll need a chain tool for the cam chain, right? Or doesn't it need to come apart? I'm fairly sure I'll be able to borrow a flywheel puller.
Should I get a case splitter, like these ones from Tusk or Motion Pro?
A crank puller/installer?
A clutch hub holder?
Micrometer?
Digital calipers?
Dial indicator ("clock")?
And then I'd really appreciate some pointers about what parts we can KNOW beforehand I'll need to replace. Do I need a full gasket set? Or just a headgasket?
Let's assume that the rod and big-end bearing need replacement for sure. Will the debris have trashed things like main bearings and oil pumps? Should parts like this be replaced on principle, or can they be checked and verified as bad or good? The bike hasn't been ridden much, only 46 hours on the clock. So these items probably won't be worn from standard use, only from having bearing trash forced through them.
I am looking forward to the task, and want to take it slow, select good parts, and build a reliable motor. I really love this bike and want to do this right ... but I am a little cash-shy so I have to save where I reasonably can I'd prefer to investigate and learn and check things carefully if it means I can save on parts.
So that was the wall of text. Thank you for reading
So I probably have one of the 70-degree bikes that encounter premature big-end failure. The signs so far are metal sludge + thin metal fragments in the oil screen. Plus a knocking/cattering sound.
At this stage I there are some gaps in my knowledge about tools, and what parts to replace.
I'm reasonably handy and have a decent mechanical intuition, but I'm pretty green in the motor rebuilding department. I'll have some of the finest advisors on the project I could possibly have ...
First is my grandfather who was a Citroën mechanic in the '50s/'60s, specially trained in the crazy French hydraulics they used to have in Citroën cars. He used to align crankshafts by hand with copper mallets and built his own valve cutting gear out of scrap. Great, great man. Always willing to help everybody and share what he knows. I'll be working in his aircraft hangar, next to the airplane he built - a 215kg two-seater with motor modifications, and aluminium wing tanks he welded himself. 215kg for an entire airplane, meters long and meters of wingspan! And I thought 'Bergs were light! It's like a crazy bird skeleton or steel spiderweb, wrapped tauuuu-ut in doped nylon canvas. The construction is fascinating, and then you can climb into it and fly in the air to boot. So good. I'll be sure to post some pics of it.
And then secondly I'll get some great help from some local experts who have graciously offered to drop by and help me figure things out, at least if I can scrounge up a cup of decent coffee for 'em.
And then you guys
I'm going to try to do everything myself except for pressing/aligning the crank. Will take this to a well-respected local privateer mechanic.
I have a basic set of tools - most wrenches/heads you'd need and some decent torque wrenches that cover 6-200 Nm or so. Impact screwdriver, old-school calipers, feeler gauge.
I'm going to get a dead blow hammer and a magnet-on-a-stick. I'll need a chain tool for the cam chain, right? Or doesn't it need to come apart? I'm fairly sure I'll be able to borrow a flywheel puller.
Should I get a case splitter, like these ones from Tusk or Motion Pro?
A crank puller/installer?
A clutch hub holder?
Micrometer?
Digital calipers?
Dial indicator ("clock")?
And then I'd really appreciate some pointers about what parts we can KNOW beforehand I'll need to replace. Do I need a full gasket set? Or just a headgasket?
Let's assume that the rod and big-end bearing need replacement for sure. Will the debris have trashed things like main bearings and oil pumps? Should parts like this be replaced on principle, or can they be checked and verified as bad or good? The bike hasn't been ridden much, only 46 hours on the clock. So these items probably won't be worn from standard use, only from having bearing trash forced through them.
I am looking forward to the task, and want to take it slow, select good parts, and build a reliable motor. I really love this bike and want to do this right ... but I am a little cash-shy so I have to save where I reasonably can I'd prefer to investigate and learn and check things carefully if it means I can save on parts.
So that was the wall of text. Thank you for reading
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