firstprojectbike
New Member
Hello all,
I have started my first project bike. I have no prior experience or formal training. Sorry if this is redundant. I also posted in the new member introduction. I was advised it is best to document projects in this thread to keep track.
When I bought the bike it was able to start (maybe 20% of the time), and would roughly idle at most for about 20 seconds. No mechanical clanking sounds. I was advised it could be a carburetor issue.
Here is how it sounded when I tried starting it up.
So I took those apart and realized one was missing a butterfly and the small flap on the other (the doggie door looking thing), was completely seized shut. So, I ordered a used replacement set that appeared in better condition on eBay, along with a couple carb rebuild kits.
One of the carbs just wouldn't stop leaking no matter what I did (rebuilt with the original parts and the replacement parts and various mixes and matches of both).
So, I ordered the Mikuni VM28 replacement carbs to get a "sure thing". I apologize in advance for any purists who will be offended by my decisions.
While waiting for the Mikuni carbs to come in, I decided to tackle the ignition timing. I could not for the life of me get the timing right and learned it's possible the timing advance mechanism could be out of phase. It proved much harder to remove than expected. Eventually, in the process of pulling it out, I pulled the rocker arm shafts with it, which meant I needed to take the cylinder head cover off to reinstall the shafts correctly. That's when I learned the cover doesn't really come off so long as the engine is bolted in place and it needs to be lowered to make enough clearance with the frame. So, I unbolted the engine and successfully got the cover off, but still didn't have enough room to work withto get the shafts back in place...so...
I removed the whole engine from the frame and put it on my work bench. At that point, for whatever reason, (and I truly do not remember why I decided to do this), I just kept taking the bike apart. I think the rational was something like, "welp, I'm this far in, might as well continue" but it is all a blur.
So, now I have the bike torn apart in a million pieces all over my garage. I hope the sight of it isn't too upsetting.
Where do I go from here? My plan is to get back to the ignition: reinstall the rocker arm shafts, the ignition advance mechanism and timing points (in phase hopefully), and maybe clean up and polish the outside of the engine while I have it on the bench. I would like to do that sooner rather than later while I have some recollection of how the timing advance mechanism was assembled.
After that, I think I might bounce around between cleaning and replacement tasks. Since, I have the entire bike disassembled, now seems like the best time to do some things like getting the frame sandblasted and powder coated, addressing the rust on the rims and spokes, replacing the brakes and tires, rebuilding the forks, repaint the fuel tank, etc. Then once everything is clean and tidy, rebuild it from the ground up - Mikuni carbs and all.
That brings me to my first two questions for this group.
Question 1: How much rust is too much rust?
As in, at what point would I be better off replacing a part versus trying to restore a part? Below are a few images for example.
Question 2: Should I do a top end rebuild just because?
I was talking with a mechanic about my project bike, and he recommended doing a full top end rebuild while I have the engine out. Is that a good idea or does it only make sense to do that if I have a specific reason; like there is a specific problem, and a top end rebuild is the most likely solution to fix the problem.
I have started my first project bike. I have no prior experience or formal training. Sorry if this is redundant. I also posted in the new member introduction. I was advised it is best to document projects in this thread to keep track.
When I bought the bike it was able to start (maybe 20% of the time), and would roughly idle at most for about 20 seconds. No mechanical clanking sounds. I was advised it could be a carburetor issue.
Here is how it sounded when I tried starting it up.
So I took those apart and realized one was missing a butterfly and the small flap on the other (the doggie door looking thing), was completely seized shut. So, I ordered a used replacement set that appeared in better condition on eBay, along with a couple carb rebuild kits.
One of the carbs just wouldn't stop leaking no matter what I did (rebuilt with the original parts and the replacement parts and various mixes and matches of both).
So, I ordered the Mikuni VM28 replacement carbs to get a "sure thing". I apologize in advance for any purists who will be offended by my decisions.
While waiting for the Mikuni carbs to come in, I decided to tackle the ignition timing. I could not for the life of me get the timing right and learned it's possible the timing advance mechanism could be out of phase. It proved much harder to remove than expected. Eventually, in the process of pulling it out, I pulled the rocker arm shafts with it, which meant I needed to take the cylinder head cover off to reinstall the shafts correctly. That's when I learned the cover doesn't really come off so long as the engine is bolted in place and it needs to be lowered to make enough clearance with the frame. So, I unbolted the engine and successfully got the cover off, but still didn't have enough room to work withto get the shafts back in place...so...
I removed the whole engine from the frame and put it on my work bench. At that point, for whatever reason, (and I truly do not remember why I decided to do this), I just kept taking the bike apart. I think the rational was something like, "welp, I'm this far in, might as well continue" but it is all a blur.
So, now I have the bike torn apart in a million pieces all over my garage. I hope the sight of it isn't too upsetting.
Where do I go from here? My plan is to get back to the ignition: reinstall the rocker arm shafts, the ignition advance mechanism and timing points (in phase hopefully), and maybe clean up and polish the outside of the engine while I have it on the bench. I would like to do that sooner rather than later while I have some recollection of how the timing advance mechanism was assembled.
After that, I think I might bounce around between cleaning and replacement tasks. Since, I have the entire bike disassembled, now seems like the best time to do some things like getting the frame sandblasted and powder coated, addressing the rust on the rims and spokes, replacing the brakes and tires, rebuilding the forks, repaint the fuel tank, etc. Then once everything is clean and tidy, rebuild it from the ground up - Mikuni carbs and all.
That brings me to my first two questions for this group.
Question 1: How much rust is too much rust?
As in, at what point would I be better off replacing a part versus trying to restore a part? Below are a few images for example.
- Rims and spokes: I think the spokes should probably go, but I don't know if the rims are salvageable.
- Header pipes: I know that removing the rust won't restore the missing chrome, and re-chroming can be expensive. Would it be cheaper to buy a set in better condition from eBay? Are these functional as is (especially the one on the left)?
- Steering stem: This looks like a lot of rust, but obviously aesthetics aren't a concern. If I clean it up and apply some kind of anti-corrosive solution, is this fine to reuse?
- Luggage rack: This is the area of least concern since it's an optional accessory. However, I do think it's cool and would like to restore if it's reasonably practical to do so.
Question 2: Should I do a top end rebuild just because?
I was talking with a mechanic about my project bike, and he recommended doing a full top end rebuild while I have the engine out. Is that a good idea or does it only make sense to do that if I have a specific reason; like there is a specific problem, and a top end rebuild is the most likely solution to fix the problem.
