- Joined
- May 6, 2014
- Messages
- 1,981
- Reaction score
- 1,931
- Points
- 113
- Location
- Amoungst the Twisty Roads
About a month ago I read an article on RevZilla Common Thread by Andy Greaser about bringing an EX-500 back to life for the purpose of riding it at something called the Reliability Rally. The Reliability Rally is a weekend event of people who have spent less than $1,000 on their bikes. The article was interesting enough but I didn't think about it any further. Until 2 weeks ago. Andy posted a follow-up story about the Reliability Rally itself. I read the article and said to myself "these are my people". I immediately started a quest to find a bike that would fit in (my current customs fit the description, but their expensive modifications don't seem in keeping with the spirit of the event). I'll put a link to the articles below.
I started looking on Craigslist and FB Marketplace, as well as a few of the auction sites where you can get rideable wrecks with salvage titles. I didn't have anything in particular in mind, but as I saw bikes in the sub $1,000 (or near enough to it) I thought to myself "would I want to spend a weekend on that thing". That eliminated every bike that put my legs/feet in the birthing position. I was kind of thinking Bandit or Katana 600, air cooled Honda or maybe an early Hurricane 600. I did see an FZ6 with impact damaged forks and thought "R6 conversion"...but I thought the frame might have some hidden problems. Then Friday night I saw on Craigslist a bike that I would never want to own in a thousand years - but it looked so right. It spoke to me.
The bike is an '81 Honda CB900C. The CB900 was Honda's first DOHC engine (also released at the same time were the CB750 & 1100 DOHC bikes) and replaced the decade old design that started with the CB750 SOHC. But the CB900C is an oddity. It was designed specifically for the American market, and was intended to compete with factory "customs" from Suzuki and Yamaha (GS850 & XS850). These bikes had shaft drive and Honda too felt that it's new air-cooled flagship should have shaft drive. But Honda didn't want to invest too much into the design because the water cooled CBR's were already in design. So they cobbled together a system that would provide a shaft drive...to the right side of the bike. In doing so they also created a hi/low gear box that could be shifted on the fly - essentially giving the bike a 10-speed gearbox. The system proved to be robust, and it allowed the bike to have a significant mpg advantage over its competition. It also added 100 pounds to the bike. Also odd are front & rear air suspension (sharred with the GL). At 600 pounds it's a big bike...and it's long too. Anyway, the photo's caused me to click into the ad.
The ad stated that the bike only had 35,000 miles, but noted that the front brakes were inoperative, that the engine smoked and that the air suspension didn't hold air for long. Sounds good to me. Also a big plus, the bike was just 3 miles from me. On inspection I saw a bike that had lived an easy life, but maintenance wasn't the owners forte'. Yes, the front master cylinder was indeed inoperative. The rear tire was the wrong size (it was rubbing on the right side swingarm/driveshaft cover). It started and ran great - even on old fuel. I didn't note any smoke on start-up, but I did hear a cam chain that was in need of adjustment. "Would you take $500?" “Sure”. I told the owner that I needed a day to think about it and to look up how to resolve the issues I observed. I was most concerned about the unobserved smoke. Doing some research showed that these engines smoke for the same reason as any other engine; a head gasket leak or stuck rings. Since there was absolutely no smoke on start-up, that eliminated a valve seal. Also, the engine ran so smoothly that I couldn't believe that one or more of the cylinders wasn't firing. I'd rather swap a head gasket then rebuild a head...so I'm thinking "yes".
I went back Sunday afternoon to pick-up the bike. I made sure that I started it myself, and it started even better after being run the day before. No smoke. I let it fully warm up and didn't observe any smoke. Great. So I handed the gentleman my money and off I went. Given that I knew I didn't have front brakes I had my son (who drove me there) follow about 100 feet behind. I was gonna take my time getting home. The three roads I would need to ride on are sparsely traveled with 35 mph limits. The rear tire was rubbing so badly that brakes weren't necessary. Every time I let off the throttle the bike came to an intimidate stop. After a mile of riding I could smell smoke. I looked in the mirror and I could see smoke. I thought it might be from the rear tire. I had to give this (smooth running) engine quite a bit of throttle to keep it moving. Just a mile from home I turned on to my street. A quick check of the mirror showed a cloud of smoke like I had never seen before. Holy smokes, this thing smokes. I made it up my driveway and pulled right into the garage. Oil was pouring onto my garage floor...not dripping. The head was dry, but the #1 cylinder was drenched in oil. Clearly, this bike needs a head gasket. The rear tire was in fact smoking too. Also smoking was the rear brake - which was also locked-up. And I'm ok with all of it - these are all simple (but involved) fixes. For the 10 seconds this bike was running in my garage, the fog was think and breathing was not possible. I actually had to go take a shower.
Here's my theory on the head gasket leak. The rear tire should be a round profile 130/90. This bike has a square profile 140/90 (Engager by Kenda). It has obviously rubbed on the swingarm since the day it was installed. This tire looks well used, so I'm thinking that under light loads, the engine is fine. But the way this tire rubs, it has to overcome significant drag - imagine if the bike was pulling a 3,000 pound trailer (I'm not kidding it's that much drag) - requiring 1/2 throttle just to go 30 mph. That's what blew this head gasket.
I will disassemble the body parts, degrease and powerwash the engine and frame, and then begin tear down of the engine. My Clymer manual will be here tomorrow. So that's my winter project.
I started looking on Craigslist and FB Marketplace, as well as a few of the auction sites where you can get rideable wrecks with salvage titles. I didn't have anything in particular in mind, but as I saw bikes in the sub $1,000 (or near enough to it) I thought to myself "would I want to spend a weekend on that thing". That eliminated every bike that put my legs/feet in the birthing position. I was kind of thinking Bandit or Katana 600, air cooled Honda or maybe an early Hurricane 600. I did see an FZ6 with impact damaged forks and thought "R6 conversion"...but I thought the frame might have some hidden problems. Then Friday night I saw on Craigslist a bike that I would never want to own in a thousand years - but it looked so right. It spoke to me.
The bike is an '81 Honda CB900C. The CB900 was Honda's first DOHC engine (also released at the same time were the CB750 & 1100 DOHC bikes) and replaced the decade old design that started with the CB750 SOHC. But the CB900C is an oddity. It was designed specifically for the American market, and was intended to compete with factory "customs" from Suzuki and Yamaha (GS850 & XS850). These bikes had shaft drive and Honda too felt that it's new air-cooled flagship should have shaft drive. But Honda didn't want to invest too much into the design because the water cooled CBR's were already in design. So they cobbled together a system that would provide a shaft drive...to the right side of the bike. In doing so they also created a hi/low gear box that could be shifted on the fly - essentially giving the bike a 10-speed gearbox. The system proved to be robust, and it allowed the bike to have a significant mpg advantage over its competition. It also added 100 pounds to the bike. Also odd are front & rear air suspension (sharred with the GL). At 600 pounds it's a big bike...and it's long too. Anyway, the photo's caused me to click into the ad.
The ad stated that the bike only had 35,000 miles, but noted that the front brakes were inoperative, that the engine smoked and that the air suspension didn't hold air for long. Sounds good to me. Also a big plus, the bike was just 3 miles from me. On inspection I saw a bike that had lived an easy life, but maintenance wasn't the owners forte'. Yes, the front master cylinder was indeed inoperative. The rear tire was the wrong size (it was rubbing on the right side swingarm/driveshaft cover). It started and ran great - even on old fuel. I didn't note any smoke on start-up, but I did hear a cam chain that was in need of adjustment. "Would you take $500?" “Sure”. I told the owner that I needed a day to think about it and to look up how to resolve the issues I observed. I was most concerned about the unobserved smoke. Doing some research showed that these engines smoke for the same reason as any other engine; a head gasket leak or stuck rings. Since there was absolutely no smoke on start-up, that eliminated a valve seal. Also, the engine ran so smoothly that I couldn't believe that one or more of the cylinders wasn't firing. I'd rather swap a head gasket then rebuild a head...so I'm thinking "yes".
I went back Sunday afternoon to pick-up the bike. I made sure that I started it myself, and it started even better after being run the day before. No smoke. I let it fully warm up and didn't observe any smoke. Great. So I handed the gentleman my money and off I went. Given that I knew I didn't have front brakes I had my son (who drove me there) follow about 100 feet behind. I was gonna take my time getting home. The three roads I would need to ride on are sparsely traveled with 35 mph limits. The rear tire was rubbing so badly that brakes weren't necessary. Every time I let off the throttle the bike came to an intimidate stop. After a mile of riding I could smell smoke. I looked in the mirror and I could see smoke. I thought it might be from the rear tire. I had to give this (smooth running) engine quite a bit of throttle to keep it moving. Just a mile from home I turned on to my street. A quick check of the mirror showed a cloud of smoke like I had never seen before. Holy smokes, this thing smokes. I made it up my driveway and pulled right into the garage. Oil was pouring onto my garage floor...not dripping. The head was dry, but the #1 cylinder was drenched in oil. Clearly, this bike needs a head gasket. The rear tire was in fact smoking too. Also smoking was the rear brake - which was also locked-up. And I'm ok with all of it - these are all simple (but involved) fixes. For the 10 seconds this bike was running in my garage, the fog was think and breathing was not possible. I actually had to go take a shower.
Here's my theory on the head gasket leak. The rear tire should be a round profile 130/90. This bike has a square profile 140/90 (Engager by Kenda). It has obviously rubbed on the swingarm since the day it was installed. This tire looks well used, so I'm thinking that under light loads, the engine is fine. But the way this tire rubs, it has to overcome significant drag - imagine if the bike was pulling a 3,000 pound trailer (I'm not kidding it's that much drag) - requiring 1/2 throttle just to go 30 mph. That's what blew this head gasket.
I will disassemble the body parts, degrease and powerwash the engine and frame, and then begin tear down of the engine. My Clymer manual will be here tomorrow. So that's my winter project.
From scrap to street: Preparing a crashed Ninja for a junk bike rally - RevZilla
Fixing up a Ninja 500 to enter the Reliability Rally, an event for cheap bikes only.
www.revzilla.com
Reliability Rally report: Sub-$1,000 motorcycles, 400 miles, two days, one trophy - RevZilla
A battered EX500 competes against a rally full of junk bikes in West Virginia.
www.revzilla.com
Last edited: