MikeJ
Member
Hi Everyone -
Just another post, mostly for entertainment value... Attached should be some photos. (It is amazing what other riders in this forum thread have done with other sizes of Honda engines!)
I made a major improvement to my bike recently. Some you of you may recall that I had a 79cc Harbor Freight engine (2.5 claimed HP) on my very-much-modified bike. The engine proved marginal at best at this >5500 feet above sea level altitude with its thinner air. I am sure it would run great at below 3000 feet. But I just don't have that option.
So I went to something overkill... A Honda GX-160. It is a 4-stroke, 163cc, horizontal shaft commercial grade engine. (I did a lot of measuring, reading and test fitting in a mock-up before ordering from Tulsa Engines. I did not want to make a very expensive mistake!)
Honda used to claim 5.5 HP from this stock engine; randomly selected production engines test out at 4.8 HP according to a new international standard for small engine testing.
So the engine arrived a couple of weeks ago. What is the second thing I do (after I examine it)? Take it apart, of course. Remove gas tank, remove muffler, and remove air cleaner. Then check it for fit. It fits in the bike!
Then I order parts from Affordable Go Karts. They sell up-performance parts for select Honda engines. After parts arrive, I remove the flywheel, remove all governor parts, replace flywheel, and remove the crankcase oil level sensor and associated wires. I install a higher-lift cam and stronger valve springs, and test fit a low restriction air cleaner and a low-restriction exhaust system. (One can safely assume Honda will no longer honor their usual three-year warranty.)
The engine gets mounted; hooked up the muffler, air intake, and provide fresh gasoline. 18 ounces of Castrol 10W-30 SJ oil goes into the crankcase. I pull and pull on the rope, but it just won't start. It backfires a few times. Now what? (Old-heads may know the answer....)
So I take the engine all apart again, front, back, and top WITHOUT removing the engine from its mount points (nice discovery!). I found the problem... I installed the new cam gear off by one tooth to the crankshaft. DUH! How careless! Fixed it, double-checked every nut, bolt, and gap again, then reassembled. Replaced oil and gas and pulled the rope. It fired! And sounded good! This is a really responsive engine; it has a really short throttle plate arm.
I let it fast idle for two hours just to listen for any strange noises and start the break-in process. This morning, I prep the bike frame (tires, look for loose nuts and bolts, adjust brakes, etc.). Put on riding gear (helmet, bright jacket, etc.) and take the bike out to local streets.
This engine has a LOT of pulling power, even at this altitude. I am impressed! Of course, that should be expected, also. The first ride was for only 20 minutes. Lessons learned: More adjustments are needed. The air filter is in the way of peddling, it needs relocating closer to the centerline of the bike frame. Have to work that. The exhaust needs relocating closer to the frame because my leg rubs against it when peddling; maybe routing it forward is the answer. Even with muffler wrap; the pipe gets much too hot for safe riding. (A replacement run-forward pipe from Affordable Go Karts has been ordered.) Third, the throttle control needs to be toned down. Right now, just a little twist of the throttle means big acceleration (don't need that mistake when approaching an intersection). The fix to that one is easy.
What will top speed be? Answer: Way too fast for me to even try. I intend to hold my speed to 30 mph. If I need to go faster, I will drive my quarter-ton pickup truck.
The first photo shows my build after this morning's run. This engine has a really hot exhaust; see the color of the pipe.
The second photo shows the engine, mounts, and clearance. The hard-to-see little stub of yellow wire near front of the engine is all that remains of the oil level sensor circuit. The red knob is the ignition kill switch. I should route the wire to a kill switch on the handlebars.
The third and fourth photos are of the right-hand side of the bike.
The fifth photo shows the protuding air cleaner and exhaust pipe. I have to get them closer to the centerline.
I worked on this bike and electronic circuits and flat tire problems as time permitted. There is always some little feature that can be incorporated. I intend that after the intake and exhaust problems are fixed, more riding time will follow. Will post more later.....
MikeJ
Just another post, mostly for entertainment value... Attached should be some photos. (It is amazing what other riders in this forum thread have done with other sizes of Honda engines!)
I made a major improvement to my bike recently. Some you of you may recall that I had a 79cc Harbor Freight engine (2.5 claimed HP) on my very-much-modified bike. The engine proved marginal at best at this >5500 feet above sea level altitude with its thinner air. I am sure it would run great at below 3000 feet. But I just don't have that option.
So I went to something overkill... A Honda GX-160. It is a 4-stroke, 163cc, horizontal shaft commercial grade engine. (I did a lot of measuring, reading and test fitting in a mock-up before ordering from Tulsa Engines. I did not want to make a very expensive mistake!)
Honda used to claim 5.5 HP from this stock engine; randomly selected production engines test out at 4.8 HP according to a new international standard for small engine testing.
So the engine arrived a couple of weeks ago. What is the second thing I do (after I examine it)? Take it apart, of course. Remove gas tank, remove muffler, and remove air cleaner. Then check it for fit. It fits in the bike!
Then I order parts from Affordable Go Karts. They sell up-performance parts for select Honda engines. After parts arrive, I remove the flywheel, remove all governor parts, replace flywheel, and remove the crankcase oil level sensor and associated wires. I install a higher-lift cam and stronger valve springs, and test fit a low restriction air cleaner and a low-restriction exhaust system. (One can safely assume Honda will no longer honor their usual three-year warranty.)
The engine gets mounted; hooked up the muffler, air intake, and provide fresh gasoline. 18 ounces of Castrol 10W-30 SJ oil goes into the crankcase. I pull and pull on the rope, but it just won't start. It backfires a few times. Now what? (Old-heads may know the answer....)
So I take the engine all apart again, front, back, and top WITHOUT removing the engine from its mount points (nice discovery!). I found the problem... I installed the new cam gear off by one tooth to the crankshaft. DUH! How careless! Fixed it, double-checked every nut, bolt, and gap again, then reassembled. Replaced oil and gas and pulled the rope. It fired! And sounded good! This is a really responsive engine; it has a really short throttle plate arm.
I let it fast idle for two hours just to listen for any strange noises and start the break-in process. This morning, I prep the bike frame (tires, look for loose nuts and bolts, adjust brakes, etc.). Put on riding gear (helmet, bright jacket, etc.) and take the bike out to local streets.
This engine has a LOT of pulling power, even at this altitude. I am impressed! Of course, that should be expected, also. The first ride was for only 20 minutes. Lessons learned: More adjustments are needed. The air filter is in the way of peddling, it needs relocating closer to the centerline of the bike frame. Have to work that. The exhaust needs relocating closer to the frame because my leg rubs against it when peddling; maybe routing it forward is the answer. Even with muffler wrap; the pipe gets much too hot for safe riding. (A replacement run-forward pipe from Affordable Go Karts has been ordered.) Third, the throttle control needs to be toned down. Right now, just a little twist of the throttle means big acceleration (don't need that mistake when approaching an intersection). The fix to that one is easy.
What will top speed be? Answer: Way too fast for me to even try. I intend to hold my speed to 30 mph. If I need to go faster, I will drive my quarter-ton pickup truck.
The first photo shows my build after this morning's run. This engine has a really hot exhaust; see the color of the pipe.
The second photo shows the engine, mounts, and clearance. The hard-to-see little stub of yellow wire near front of the engine is all that remains of the oil level sensor circuit. The red knob is the ignition kill switch. I should route the wire to a kill switch on the handlebars.
The third and fourth photos are of the right-hand side of the bike.
The fifth photo shows the protuding air cleaner and exhaust pipe. I have to get them closer to the centerline.
I worked on this bike and electronic circuits and flat tire problems as time permitted. There is always some little feature that can be incorporated. I intend that after the intake and exhaust problems are fixed, more riding time will follow. Will post more later.....
MikeJ
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