Oil filter cover repair on the go
 

I was riding when oil started to leak, the oil filter thread no longer hold.

So i fixed it with springs and this is working fine this is an idea if you get stuck somewhere..

nice idea but get a M6 helicoil kit to fix properly. sudden oil on your rear tire is no fun.

once had a plug in my CB500/4 road racer strip in practice, did the race with it being held down with safety wire.... it held, finished 9th :)
fixed with helicoil for next race..

I remember one of the bolts on my 43f stripped the threads. I was able to fit a slightly longer bolt which seemed to use threads that were deeper in the casing. Bike ran fine after this mod but be carefull as I dont know where those holes lead to and what trouble may happen if you put too long a bolt in there. I probably just used a bolt that was 10mm longer.

The lower bolt is the special one that is open to an oil passage and it often the one that gets over torqued due to leaking because nobody uses a sealing washer . It can be tapped all the way through but has limited material for a good strength but can work .

The 2 top holes , IMHO should be tapped to the bottom of hole from the start (bottoming tap or thread form tap) and longer bolts sourced . This will prevent thread stripping considerably with double the number of threads taking the stress . Even torquing to spec the threads take a lot of abuse from repeated removal and retightening from oil changes over the years . I actually put studs in mine , blue loctited in place and use acorn nuts to hold the cap in place , thus no aluminum threads get worn from use and all issues are gone . The "special" hole needs a stepped stud though but I've gotten away with a rubber washer under the nut .

Eventually i fitted helicoil but they did not hold!!!! Although i fitted helicoil before? So i dont know how i could fix it for good now even if the swivel exhaust spring fitted hold well.

I drilled at 6.5 mm with the helicoil kit. So maybe i can still fit m6 insert ? If those insert need a 7mm drill.

I dont know
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Did both of those top holes strip out ? How deep are the threads gone ? take a small drillbit and see how much deeper the hole are and if longer bolts will work . Otherwise depending on wall thickness tap entire hole to 8mm x 1.25mm and use stepped studs . Thread the 8mm down into the holes with blue loctite , and the 6mm portion will fit through the cap . Then just use nuts and torque down way less than has been, it's the main reason they strip out .


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I'd suggest as well that to avoid cuttings getting into engine internals that the tap be loaded up with grease and cleaned out every few turns. Might be OTT but it's what I'd do just to be sure.

Good to know thanks. I tapped and inserted helicoil with WD40 this is why i beleive they did not hold then.

The stepped studs will work on the clutch cover as i dont think i could find studs long enough to go through all the way to the crankcase?

Otherwise what about threaded insert to replace heli oil?
Yamaha suggested to fit those for me but at a cost of 300 euros....

I normally use keenserts for repairing threads if there is enough material https://www.mcmaster.com/key-locking-threaded-inserts . I absolutely hate helicoils due to failures common and then you have an even bigger hole to fix . For something with low torque specs and will only be tightened once they're not that bad , just not for repeated re-torquing .

The step stud would need to be 65-75mm IIRC . Take an 8mm bolt(cut the head of) or chunk of threaded rod and drill and tap it for 6mm x 1. then Loctite a 6mm stud or threaded rod into it ( red or orange -#277 Loctite) , walla , long stepped stud . Helps to have access to a lathe .

A person could even just drill the 8mm bolt/all-thread using a 5mm drill and turn the 6mm stud/all-thread down to 5mm and press it into the 8mm hole so the ends are flush and weld it on the end so it won't pull out . Or just turn and thread your own stepped stud on the lathe using an 8mm x 80mm bolt -10.9 grade , leaving the 8mm threads on one end and rethreading the other after turning it down to 6mm.


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