1985 Gyro X Restoration Help
Posted: Mon Aug 06, 2012 4:55 pm
Hi guys,
I have been browsing your forum for help the past month or so as I have been restoring a 1985 Gyro X that I believe was imported from Japan. Most of my work up until the past few days has been cosmetic, which was a pain since every square inch of the bike was covered in combinations of dust, dirt, and oil.
Now I have moved onto the mechanical side, which I thought would be a breeze since the bike was in running order 3 years ago. I cleaned up the carburetor and fuel/vacuum apparatus (not sure what it's called) with a good amount of carb cleaner and compressed air. I also replaced the disgustingly dirty stock air filter with some carefully cut out pre-filter element from Napa. I completely drained the fuel/oil lines and primed them before cranking the motor. However, I could not get the engine to turn over (or even begin to spark), so I started researching other issues. I downloaded a 1984 Gyro (NN50MD) manual from this forum, but it is a very different bike than my Gyro X (I have a vertical cylinder, the manual's has a horizontal). Anyways, I have used it for reference for parts that are similar between the bikes. Here are the things I have done with the engine so far:
I tested the compression of the motor and got a measely 75 psi, which is much lower than the manual's stated 175 psi for the NN50MD. Does anyone know what the recommended compression is for the Gyro X?
I then took off the cylinder head to examine the top end, and found something surprising: the gasket is made out of sheet metal.
Despite this, the engine ran fine 3 years ago with the same gasket.
The cylinder walls looked to be in decent shape, but I do not have the tools in my garage to check tolerances.
My main question I would like answered is if the 75 psi compression is appropriate to get a running motor. If not, do you think the POS gasket could be causing it? Or could it be that I might have to bore out the cylinder? I can supply you guys with more top end pics if necessary. If 75 psi is appropriate, what else do you think could be causing the motor to not turn over? Because I haven't been able to get any ignition so far. Any help would be greatly appreciated, as I have to get this project done in the next few weeks before I head back to school.
I have been browsing your forum for help the past month or so as I have been restoring a 1985 Gyro X that I believe was imported from Japan. Most of my work up until the past few days has been cosmetic, which was a pain since every square inch of the bike was covered in combinations of dust, dirt, and oil.
- After I cleaned up the front end.
- IMG_20120717_174449.jpg (159.48 KiB) Viewed 2723 times
I tested the compression of the motor and got a measely 75 psi, which is much lower than the manual's stated 175 psi for the NN50MD. Does anyone know what the recommended compression is for the Gyro X?
I then took off the cylinder head to examine the top end, and found something surprising: the gasket is made out of sheet metal.
- Is this hackjob of a gasket normal?
- IMG_20120803_165142.jpg (129.64 KiB) Viewed 2723 times
The cylinder walls looked to be in decent shape, but I do not have the tools in my garage to check tolerances.
My main question I would like answered is if the 75 psi compression is appropriate to get a running motor. If not, do you think the POS gasket could be causing it? Or could it be that I might have to bore out the cylinder? I can supply you guys with more top end pics if necessary. If 75 psi is appropriate, what else do you think could be causing the motor to not turn over? Because I haven't been able to get any ignition so far. Any help would be greatly appreciated, as I have to get this project done in the next few weeks before I head back to school.
