Home › Forum › Ask A Member › 1975 Chrysler 10hp 2 stroke refurbish questions
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adiastra.
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May 2, 2018 at 12:31 am #9797
Ok here is my engine.
https://www.youtube.com/watch?v=MAINXaCK2mc&t=45s
I purchased it in running condition off craigslist for $150. I found that it overheated so I started learning about these engines (im new to marine engines)That video was taken after I replaced the fuel pump gaskets, inline fuel filter and impeller (which was the main issue)
I have followed this video about tuning the carb https://www.youtube.com/watch?v=6bTsQC0zDIc as best as I can, and have been watching as many of Ben’s videos that relate to my motor as I can. As such I have also ordered condensers and will pop off the flywheel and replace the condensers/clean the points.
Everything is going well and I believe this engine will do what I need it to do.
The only question I have is about a slight cracking sound that can be heard at high revs. This is a sound I have heard before on dirt bikes but it just sounds harsh. If this is normal then all is well, but im just not sure. Is there a good video of what a high revving small 2 cycle outboard sounds like? I just dont want to get on the water and blow this thing up.
Side note I have 91 octane in in and we have E10 here. All the rubber on this engine seems to have been replaced fairly recently (the fuel pump gasket was the new version, the hoses are supple and soft). Not sure if that makes a difference as it relates to my question but figured I would include that info.
May 2, 2018 at 1:58 am #75179Sounds to me like it is "four stroking" which is normal when the engine is revved in a no load condition. You really shouldn’t run it much above a fast idle without a load.
May 2, 2018 at 2:07 am #75181…agree with RCO….please do not rev without a load…put it in water and let us know how it runs..;)
May 2, 2018 at 5:06 am #75191The motor itself sounds good but I can hear what sounds like the reed valves howling away. Two-stroke intake systems are typically noisy because of the reeds and in the fifties, all Johnson/Evinrude motors came with silencers for the intake system and we all know how nice those motors sound!
May 2, 2018 at 11:22 am #75194quote RCO:Sounds to me like it is “four stroking” which is normal when the engine is revved in a no load condition. You really shouldn’t run it much above a fast idle without a load.I listened to the video several times and didn’t hear anything unusual. But "four stroking" is a definite possibility, which is normal as said. The main thing I heard was my body cringing as I listened to that thing revving so high under no load. Must be a good motor because it didn’t blow up–yet.
I will say one thing, that is a very smooth running motor, practically no vibration.
May 2, 2018 at 12:14 pm #75197Awesome, sounds like a pretty clear diagnosis. Thanks so much guys. I will never reve it that high again without load, I promise 🙂 I listened to this https://www.youtube.com/watch?v=0wzph3hL6EE and while not even close to the same, i could hear the similarity enough to to fully agree with what you are saying.
Now is there any thing else I should be doing to this motor before I lake test it? Plugs and wires are good, as I said i have condensers on the way and will clean up the points when im under the flywheel.
I kind of feel like its in great shape and I should just be happy with it as is. I am glad I did what I did because I learned a bunch about my motor in the process. Which should help me diagnose any issues in the future.
May 2, 2018 at 12:22 pm #75198quote FrankR:quote RCO:Sounds to me like it is “four stroking” which is normal when the engine is revved in a no load condition. You really shouldn’t run it much above a fast idle without a load.I listened to the video several times and didn’t hear anything unusual. But “four stroking” is a definite possibility, which is normal as said. The main thing I heard was my body cringing as I listened to that thing revving so high under no load. Must be a good motor because it didn’t blow up–yet.
I will say one thing, that is a very smooth running motor, practically no vibration.
Just a note, the sound is not in this video. I did a higher rev test and heard it, once I heard it I backed off. Lucky for me i did not hurt anything and, as I said, I will not do that again.
I cant believe what a killer deal I got on this thing.
May 2, 2018 at 12:49 pm #75203quote adiastra:Awesome, sounds like a pretty clear diagnosis. Thanks so much guys. I will never reve it that high again without load, I promise 🙂 I listened to this https://www.youtube.com/watch?v=0wzph3hL6EE and while not even close to the same, i could hear the similarity enough to to fully agree with what you are saying.Now is there any thing else I should be doing to this motor before I lake test it? Plugs and wires are good, as I said i have condensers on the way and will clean up the points when im under the flywheel.
I kind of feel like its in great shape and I should just be happy with it as is. I am glad I did what I did because I learned a bunch about my motor in the process. Which should help me diagnose any issues in the future.
That motor has been run hot enough to burn the paint. Just my personal opinion, through experience, that the head gasket and exhaust cover gaskets should be changed. If nothing else, at least re-torque the bolts. Your choice, just sayin’….
May 2, 2018 at 12:55 pm #75204quote FrankR:That motor has been run hot enough to burn the paint. Just my personal opinion, through experience, that the head gasket and exhaust cover gaskets should be changed. If nothing else, at least re-torque the bolts. Your choice, just sayin’….Where do you see burnt paint? The paint on the power head is in perfect condition.
May 2, 2018 at 2:18 pm #75209I see brown-ish paint on the powerhead, and the rest of the motor is white. Opinions may vary
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