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  • November 28, 2020, 12:05:55 PM

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Author Topic: Cleaning the 4-stroke engines  (Read 159 times)

Offline Mike Alimov

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Cleaning the 4-stroke engines
« on: May 06, 2020, 10:05:07 AM »
A few of my Saitos have developed oil varnish on the outside, and what's worse, on the valve stems, and I'd like to give them good cleaning before putting away for long-term storage.  I'd like to hear from those who have successfully cleaned their Saito engines - what method did you use? (I favor the crock pot myself, but only used it on 2-strokes, fully disassembled).  To what degree did you take the engine apart?  Did you remove the valves?  Did the engine run any different after cleaning?
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Online Massimo Rimoldi

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Re: Cleaning the 4-stroke engines
« Reply #1 on: May 06, 2020, 03:08:29 PM »
Hi.
If you have used the engine with a fuel containing castor oil I advise you to completely disassemble it and to check very well the cleanliness of the camshaft bushing. Check that the lubrication hole is completely open. Obviously it eliminates all combustion residues from valves etc.

Massimo

Offline Mike Alimov

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Re: Cleaning the 4-stroke engines
« Reply #2 on: May 07, 2020, 02:46:44 PM »
Thank you for your reply Massimo, but I still don't understand what method of cleaning you used (chemical, solvent, antifreeze, cold or hot?) and to what degree did you disassemble the engine, especially the top end (valves, etc).

Anybody else cleaned their Saito?
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Online Massimo Rimoldi

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Re: Cleaning the 4-stroke engines
« Reply #3 on: May 07, 2020, 03:13:00 PM »
Hi.
The engine has been COMPLETELY disassembled.  For cleaning I use cold solvent naphtha (CAS number 64742-89-8), but the crock pot system can do the job.

Massimo

Offline Mike Alimov

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Re: Cleaning the 4-stroke engines
« Reply #4 on: May 07, 2020, 06:24:20 PM »
Thank you!  I will try that tomorrow.
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Offline Mike Alimov

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Re: Cleaning the 4-stroke engines
« Reply #5 on: May 11, 2020, 01:45:32 PM »
A quick update for the benefit of the tiny crowd that might actually be following this.  I disassembled most of the engine, but did not remove the rockers, springs, or valves.  One of the paper gaskets for the valve cover got torn in the process.  The rocker axle screws were in there so tight, it would have required heat to loosen them. I did not want to apply heat, so left everything as is.  Cooked the top half and bottom half of the engine (crankshaft and bearings still in the case) in antifreeze overnight.  Everything came out clean.  Parts got washed, dried with the compressed air, lubed with air tool oil, and re-assembled.  Overall, I would say that 4-stroke engine overhaul requires more advanced mechanical skills than 2-strokes.
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