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Makotosun
Center case sealant deterioration
- turbodan
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Center case sealant deterioration was created by turbodan
I recently split my '74 360 motor apart, 15k miles and 50 years after it left the factory. It's been running great but it couldn't hurt to freshen some bearings up and give it a once over. I was curious about the condition of the ancient sealant at the center case joint as well. Upon disassembly I was surprised to find two stroke oil had been pushed forward into the hollow cavities adjacent to the crankcase near the front engine mounts.
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If you've never had yours apart, it would be prudent to open it up and freshen the goop sealing the case halves. If it leaks oil I'm sure it will leak air as well.
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If you've never had yours apart, it would be prudent to open it up and freshen the goop sealing the case halves. If it leaks oil I'm sure it will leak air as well.
The following user(s) Liked this Post: JayB, Snglsmkr
15 Feb 2024 10:25
#1
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- MarkT
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Replied by MarkT on topic Center case sealant deterioration
Very common place for an air leak on a DT360.
1963 YG1-T, 1965 MG1-T, Allstate 250, 1970 CT1b, 1971 R5, 1973 AT3MX, 1974 TS400L, 1975 RD350, 1976 DT175C, 1976 Husqvarna 250CR, 1981 DT175G, 1988 DT50, 1990 "Super" DT50, 1991 RT180, 2017 XT250
15 Feb 2024 10:38
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- LongStride
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Replied by LongStride on topic Center case sealant deterioration
Not uncommon to see oil in there, curious though, even on a modern bike fairly common, and not showing leak any where else on the case half , always puzzled me
2ET703 Central Texas
15 Feb 2024 16:50
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- MarkT
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Replied by MarkT on topic Center case sealant deterioration
I have a habit of pressure testing before disassembly... several 360's and 400's I've worked on have an air leak around the front motor mount for some reason.
Here's a DT360 that had a pretty significant air leak... over 1 psi per minute.... hard to see but spraying copious amounts of soapy water around the front motor mount resulted in large soap bubbles forming around the upper mount bolt hole. I outlined in red just outside the bubble.
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Here's a DT360 that had a pretty significant air leak... over 1 psi per minute.... hard to see but spraying copious amounts of soapy water around the front motor mount resulted in large soap bubbles forming around the upper mount bolt hole. I outlined in red just outside the bubble.
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1963 YG1-T, 1965 MG1-T, Allstate 250, 1970 CT1b, 1971 R5, 1973 AT3MX, 1974 TS400L, 1975 RD350, 1976 DT175C, 1976 Husqvarna 250CR, 1981 DT175G, 1988 DT50, 1990 "Super" DT50, 1991 RT180, 2017 XT250
The following user(s) Liked this Post: JayB, Ht1kid, LongStride, Sneezles61
15 Feb 2024 18:22
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