"Maxima Speed" (maximaspeed)
03/30/2020 at 20:55 • Filed to: None
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"Maxima Speed" (maximaspeed)
03/30/2020 at 20:55 • Filed to: None | 4
| 9 |
This weekend I finally had the opportunity to dedicate several days to determining why my 1973 Honda CB350 had experienced a sudden loss of power last summer. I made great progress. Life update leads into motorcycle update so if you came purely for #twowheelsgood content just scroll down.
During a ride in July or August of last year (cant remember, too long ago), my bike suddenly lost power, oil was pouring out of the breather tube, and the engine would not stay running for any length of time. I hauled it home and due to life being crazy I couldn’t address the situation. The bike languished. I had large expenditures of money and it seemed like every time I had a little surplus money something came up. Replaced a camshaft on the ‘04 Solara, had a car accident and bought another Solara, had a root canal that I payed out of pocket, then in November I lost my job. My employer was trying to force me into assisting with tax evasion and I couldn’t assemble enough evidence in time to take to the IRS. Technically I quit but it was due to pressures from my employer to either comply or be fired. This left me without any income as of November 23rd 2019.
Now, I had seen this coming and had been saving all the money I could so when it finally came down to the wire I knew I had enough that if I scrimped along I could last until I found a job. I assumed that I would be able to find some job, any job, in my career field. At 27, I live with my parent but have helped shoulder the financial burden of running the household paying a sum equal to my fraction of living expenses. It works out well as my parents like having me around, I can help out and not feel be a burden, and yet at the same time not pay as much as if I was renting my own place. This gave me a little more time than I would other wise have had.
By early February my income was just running out when I received an opportunity (thanks to Tom McParland) to join a start up as an automotive purchasing consultant on a sort of piece work basis. This allowed me to keep paying the bills and put gas in my car for the occasional outing. During this time of unemployment I had the fortune to meet a wonderful lady who I started going out with. While completely worth it, some more experienced individuals will have noticed that having a partner (or socializing in general) cost money even when sharing expenses lol. This meant I still did not have the extra income to repair the motorcycle. I drained the fuel out of the Honda in December or January and replaced with fresh gasoline mixed with Stabil to ensure that things didn’t gum up.
Then in late February, early March came the breakthrough. I was suddenly in the process of getting a new job. A desirable job with the state which would have ample opportunity for advancement and potentially life long career growth. After a lengthy interview process (it felt long at least). I received an offer and eagerly accepted. On March 16th I started work. I love it it. Always working on something new and the recent health situation has made for a unique set of challenges for our organization to support. Finally this weekend I had the perfect combination. A c ompression tester, n o weekend plans, good weather for working outside, and the motivation to actually figure it out.
Didn’t want to start it yet because I wasn’t sure what the issue was and didn’t want to cause damage. I did a cold c ompression test and the right cylinder returned results within acceptable parameters for a cold test. The left cylinder however was returning ZERO psi. Nothing. Hmmm strange. Must be a prodigious leak I reasoned. Valve timing off? Keep in mind ive never done this level of engine troubleshooting before. These were uncharted waters .
I commenced to set the valve clearances/timing to no avail. I decided to see if I could start the engine and determine the issue from there. It stated with no trouble. The r ight cylinder ran great but the left cylinder was clearly not firing or even generating compression. My dad and I both reasoned that maybe the intake valve was in the open position as the engine would generate suction but not compression. Clearly the engine was losing so much air that it wasn’t the piston rings as there should be at least a little pressure. For some reason I was stuck on the valve idea for a long time even though literally all I had to do was turn the engine over with the valve cover off and see whether or not they were moving. By this time i m into day two.
I incorrectly thought that I needed to take the cam cover off. In the process I damaged the gasket, ugh. Eventually I realized I could check the valve movement from the valve cover *facepalm*.
After categorically determining that the valves were in fact moving I was left with two options, either the valves were so out of time that they were open at completely the wrong time (not likely) or there was a giant freaking hole somewhere. I once again plugged the spark plug hole with my finger, feeling and listening for any air. Thats when I heard it, the hiss of escaping air, very faint. “ It must be a big leak” I again thought. I listened where the sound was coming from, it wasn’t coming from either valve side, it was coming from the cylinder itself. Then the common sense lightbulb struck me. I brought the piston to top dead center and looked inside with a flash light. At first I wasn’t sure what I was seeing, it was supposed to be a flat smooth surface. I know that much about engines. Then realization........ “oooooh” thats a giant freakin hole. Thats no bueno.
So thats where I am now. The bike is most certainly down for quite some time. I’m disappointed that the bike is going to take valuable riding time to actually get running but I actually am looking forward to the learning process of completely rebuilding an engine. Im currently pricing parts. Since I have to tear it apart I may upgrade something’s along the way. For sure will try to find forged pistons as the (what looks like) cast piston doesn’t exactly inspire confidence. Stay tuned for more updates on the rebuild project as time goes by. Thanks for reading!
Bonus pics : Cherry Blossoms near work are in bloom today . Im taking the good camera (this was just the cellphone) back tomorrow and I will be doing some reshoots. I would like to get the above shot with a better camera.
sony1492
> Maxima Speed
03/30/2020 at 21:18 |
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Sounds like things were brought there for a moment with the car and job, but glad to hear its turned around and looking up.
Who is the Leader - 404 / Blog No Longer Available
> Maxima Speed
03/30/2020 at 21:37 |
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Glad to hear things turned around for you and appreciate you sharing what was surely a difficult time.
I do have one question. What happened to the bit of the p iston that is no longer extant? Was it rattling around in the chamber or what?
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Maxima Speed
> Who is the Leader - 404 / Blog No Longer Available
03/30/2020 at 22:28 |
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Thanks for reading! Good question. Cant hear it rattling around and the oil is clean as new. I guess I’ll find out when i tear it all apart
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Who is the Leader - 404 / Blog No Longer Available
> Maxima Speed
03/30/2020 at 22:29 |
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You really gotta wonder, where did it go?
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Maxima Speed
> Who is the Leader - 404 / Blog No Longer Available
03/30/2020 at 22:34 |
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It has to be sitting in the oil pan is my guess.
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Who is the Leader - 404 / Blog No Longer Available
> Maxima Speed
03/30/2020 at 22:41 |
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Since you said it didn’t dissolve into dust in the oil, there aren’t many other places it could go.
Piston Gnomes
Fuckkinja
> Who is the Leader - 404 / Blog No Longer Available
03/30/2020 at 22:50 |
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The pieces are bouncing around either the crank or the trans. Make sure to flush out the crank bearings really well before reassembling. A piston swap is pretty easy on those bikes.
DipodomysDeserti
> Maxima Speed
03/31/2020 at 00:12 |
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My 450 is currently completely apart. Thankfully the issue was a cracked timing chain tensioner bracket (spotted by a 1st grade STEM student) and the rest of the internals are kosher. My 175 needs a new ignition coil. Part of the joys of riding old bikes.
AdverseMartyr
> Maxima Speed
03/31/2020 at 09:02 |
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So, the easiest, quickest, (and quite possibly cheapest) thing to do is throw a different engine in there.
Maybe due to it’s age finding another engine might be a bit more difficult, but I’m guessing there were a lot of these, and that Honda made them virtually unchanged for a long period of time.
I’m not at all an expert on engines, but something made that piston shatter. So either it hit the spark plug or the valves. But it has to have left metal which could be who knows where, and if the crank is sharing oil space with the transmission then it could be in with all of your gears.
My experience replacing valves & piston rings on a 1990 S uzuki twin makes me guess you could replace the piston head by pulling the head & sliding the cylinder off the piston, but it wouldn’t tell you anything about the bottom, and it wouldn’t let you get the metal out.
I’m guessing you would need to do a complete disassembly, and it’s probably more expensive to buy all the gaskets, and other parts you would need than it is to find another engine.