Onan B43M, B48M and P series in re powers [Archive] - Case Colt Ingersoll Lawn and Garden Tractor Forum

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Bob MacGregor
06-28-2020, 08:49 PM
Hi Troops,
Over the years the intake manifold bolt threads in the engine get stripped. When the Case/Ingersoll heat shields are installed with lock and flat washers the stock bolts don't engage enough thread in the bolt holes and strip the threads. There is a fix for this problem. The stripped bolt holes can be repaired with thread inserts commonly known as Helicoils. The depth of these bolt holes are different which is the reason for the different bolt lengths in my pics.
This is a problem with B43M, B48M and P series Onans installed as re power replacements for the B series engines.
Two of the 4 intake manifold bolt holes on the B43M in the pics had to have Helicoil thread inserts installed in them. I discovered this when I removed the intake to clean the carb.:geek:
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