Rhylsailer99
Well-Known Member
£109 from amazon. I am guessing I will need to apply heat to soften the tbread lock or will they come out ok with the impact driver.
Is it powerfull enought to remove Bukh flywheel
- Thread starter Rhylsailer99
- Start date
Poignard
Well-Known Member
I never had any difficulty removing BUKH flywheel bolts using this much cheaper alternative
Rhylsailer99
Well-Known Member
I will try that method first, did you apply heat to the bolts firat?
KevinV
Well-Known Member
IF that achieves the claimed figures then be aware it's easily capable of shearing bolts clean off - my similarly specced dewalt certainly can (and has). Heat, then alternate short bursts of tighten/loosen.
As above - consider it a last resort, especially if the tool is new to you.
As above - consider it a last resort, especially if the tool is new to you.
Poignard
Well-Known Member
PCUK
Well-Known Member
Allen key and scaffold pole?
Poignard
Well-Known Member
And a couple of fat blokes standing on the endAllen key and scaffold pole?
neil_s
Well-Known Member
You will need to secure the flywheel from rotating if you use an Allen key. I wrap a few turns of light rope around the perimeter and tie it off to the engine bearer. I use an Allen key adaptor with my long socket set tommy bar. You will need a torque wrench to do the bolts up again, afterwards. I have heard that you shouldn't re-use the bolts, but I can't find any reference to this in the Bukh service manual so I have reused them a couple of times, now, - my flywheel hasn't fallen off!
LittleSister
Well-Known Member
I too had thought I'd read that the flywheel bolts should not be re-used, but later came across something (on this forum?) saying otherwise. I also recall reading that they are not standard bolts, but Unbrako ones (branded, extra strong ones). I now don't know what the true situation is.
You definitely do not want your flywheel coming off when the engine is running - likely to make a catastrophic mess of hull and/or bodies.
Replacement bolts from Bukh spares stockists are less than a fiver each, and I would have thought that £30 for the set is probably worth it for peace of mind.
ducked
Well-Known Member
I have found, in this sort of situation, that sharply tapping the end of any lever used with a hammer to be more effective than simple leverage.And a couple of fat blokes standing on the end
LittleSister
Well-Known Member
Yes, the vibration transmitted through bolts, etc. can be useful in releasing seized or very highly tightened parts.
vyv_cox
Well-Known Member
Unbrako socket bolts (Allen type) are marked 12.9 (1200 MPa, YS 90% of UTS). I believe that most Allen bolts are the same grade, although I have come across black painted ones that are almost certainly not. Unbrako claim that theirs are the best but I suspect that any from a reliable source would be as good. Socket Head Cap Screws | Unbrako https://share.google/c4OzcKnzwX9ItGxDj
When I had a Bukh I removed the flywheel several times and used the existing bolts each time, after an inspection for cracks or deformation.
When I had a Bukh I removed the flywheel several times and used the existing bolts each time, after an inspection for cracks or deformation.
Rhylsailer99
Well-Known Member
Thats what I was thinking. I will try heat and a socket wrench 1st. Maybe I can do the job without even removing it at all, vut I doubt that.
Rhylsailer99
Well-Known Member
I wonder if it would be a good idea to change the front crank case seal. I do have an oil leak that I cannot pinpoint. The oil ends up in random places around the front of the engine.
vyv_cox
Well-Known Member
I cannot see heat being effective at all. Presumably the threads are seized in some way, by corrosion or thread lock. Heating the bolt heads cannot reach the threads until the whole flywheel is red hot.
Poignard
Well-Known Member
By the way, what is the job you want to do, that you think you might be able to do without removing the flywheel?
If it is removing/replacing the cooling water branch, that can be done without removing the flywheel; using a hex key with its short leg shortened.
If it is renewing the engine mounts, then removing the flywheel certainly makes the job much easier.
Rhylsailer99
Well-Known Member
Engine mounts are shot at, and where they bolt into the fiberglass the bolts turn to dust, only the top quarter of the bolt comes out.
I have also noticed that the current mounts are not the standard round bukh ones and I suspect the holes do not match the new ones
.I have done some research and will probably have to re drill new holes and tap a thread and hope the plates inside the fiberglass are not rotten.
It has become one of them jobs that keep escalating, ie the flanges on the prop are rusted together solid and I need to disconnect before I start removing mounts. I have a new set of mounts now and also have a box of used red brackets spare that look better than mine, so I will use them.
James_Calvert
Well-Known Member
Just mentioning it because others haven't yet...
The flywheel is heavy, take care when you get it off.
The flywheel is heavy, take care when you get it off.
Charlie Boy
Well-Known Member
the flywheel should have been torqued on; 4-4.5kgm (28.9-32.5 ft.lbf) and thread lock used. Those figures are lifted from the manual.
It may be that a serious thread lock has been used in which case you may need to heat the head of the bolt gently before undoing.
You can purchase a hex key fitting for a torque wrench, looks just like a normal socket fitting but with a hex key tip
It may be that a serious thread lock has been used in which case you may need to heat the head of the bolt gently before undoing.
You can purchase a hex key fitting for a torque wrench, looks just like a normal socket fitting but with a hex key tip
ducked
Well-Known Member
Maybe if you put some serious current through it, using a starter battery, there would be some localised resistive heating at the threads. If youu can get a carbon arc electrode that would avoid any risk of welding your contactor inplace. Probably prudent to take precautions re the battery exploding
