4 stroke engine,carburation, EFI, and exhaust discussion
by Dirteater » Tue Jun 09, 2020 5:11 pm
I was washing my bike last night and found these cracks. They are where the swing arm bolt goes through the engine cases, chain side. It's a 2017 390rrs with 101 hrs on the clock. No big crashes or any thing that I can think of to cause this to happen. I'v checked the engine mounting bolts and they are good. Has anyone else ever seen this before?
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- Beta Cracked Eng Case 6.jpg (39.78 KiB) Viewed 2692 times
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Dirteater
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by craigy » Tue Jun 09, 2020 6:26 pm
Swing arm bolt tight? Swing arm bushes worn? frame cracked at the swing arm bolt mounting area? I looks like you are getting some flex of the swingarm bolt which is stressing the cases. I've seen similar on a KTM 400SC. Cracks were welded and no further cracking occurred.
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craigy
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by Muddaholic » Wed Jul 08, 2020 10:58 pm
That sux man ... But it looks like it can be welded by a good... as in very good Tig Welder. Looks like you will have to pull the swing arm and the bearing. But again, it is fixable....
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Muddaholic
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