Crankshaft hole cap

[Dr D 21]

Decided to check the valve clearance today, unfortunately the Crankshaft hole cap is solid. Tried tapping in spraying with lube but still no joy. Any ideas how to free this. Thought I could warm the engine and try. Obviously then leave overnight before checking the clearance. Thanks in advance.

 

DD

[Argyll 1,334]

You could try tightening it first in order to break the seal. Doesn't work that often (for me at least) but it is commonly recommended.

[Grumpy old man 4,670]

I had the same issue. I got over it by using a good T Bar and a good fitting key, then with pressure on the T bar tapping at the plug both dire t and through the socket. Failing that use an impact driver or the worst come to the worst hammer and punch. You could try boiling water on the casing 🤔.

Good luck

[Dr D 21]

Thanks, I will try after Christmas day, might be able to sneak to the workshop by then. Shhh😉

[Slowboy 20,345]

They are surprisingly expensive…. Ask me how I know🙄

 

use a bit of heat or cold and don’t use too much rotating force. They are made of a very soft aluminium.

[outrunner 4,457]

Another thing to try is putting a bit of grinding paste on the hex key to make sure it has a good grip before turning it, helped me with that, and other tight fasteners in the past.

 

Andy.

[fj_stuart 4,739]

I feel your pain. I've knackered two such caps on my CBF. I'd try an impact driver but prepare for the hex to round. It's an inherently bad design. You're trying to turn a 30mm thread with a 10mm hex (or some such) If it sticks a bit you're in trouble. As Brian says the aluminium is particularly soft. Better if it were steel. I lubricated the threads on the CBF but they still bind over time. My advice to all would be to remove the cap regularly to keep it free.

[Xactly 5,335]

16 minutes ago, fj_stuart said:

I feel your pain. I've knackered two such caps on my CBF. I'd try an impact driver but prepare for the hex to round. It's an inherently bad design. You're trying to turn a 30mm thread with a 10mm hex (or some such) If it sticks a bit you're in trouble. As Brian says the aluminium is particularly soft. Better if it were steel. I lubricated the threads on the CBF but they still bind over time. My advice to all would be to remove the cap regularly to keep it free.

Good advice. I removed both caps on mine when new and put Coppaslip on the threads. I intend to check them annually.

[Jondajon 12]

It doesn’t really help in your present situation, but for the future...the recommended torque is only 4nm! (3 ft.lb). I suspect that whoever had last checked valve clearances had tightened this cap far too much.

[dave 959]

Any inspection cap that has an O ring to seal it requires a constant low force to persuade it to let go. Now the plug has rounded off lightly tap the cap recess with a blunt chisel or screwdriver. 

[Steve Case 939]

I soaked mine in wd40 the night before, then next day used an impact driver with the best fit allen socket I had.

 

I also put some grease on the rubber o ring before putting it back.

[Dr D 21]

Thanks, lots to try. I think I will order a spare in case I have to go for the nuclear option.

Steve did you use a manual (vessel) impact driver or an electric one? I have both. I wondered if the electric  might be to much. 

 

DD

 

 

[fj_stuart 4,739]

You got me paranoid so I checked the covers on my CBF & SV. The CBF was ok - I lubed it when I got the bike this summer. The SV cover hadn't been off for a couple of years and was a bit tight. It felt that it was the O ring that had stuck to the cover & casing rather than the threads. I re-assembled it with some red (rubber) grease.

[Dr D 21]

Thanks for all the advice. Let it soak in wd40 overnight, I then put a long bar on the hex socket and taped with a hammer while applying pressure. It came undone after a few taps. I will order a new one, half tempted to turn up something a little better than this. Mr Honda is normally spot on with mechanical stuff but this is not a good design.

 

DD

[jeremyr62 2,537]

I think the design is fine, they just skimped on the aluminium alloy they used. It's far too soft.

[Steve Case 939]

cheap ole mechanical impact doubrey, always use it on cover screws that haven't been loosened in a while, and everything else.

 

I would suspect the reason they are sticky is the dealer has never touched them, can always rely on a dealer to avoid doing anything they don't feel like.

[Steve Case 939]

Oh and the Japanese aversion to using grease on anything!

[listener 11,157]

On 27/12/2021 at 16:52, Steve Case said:

Oh and the Japanese aversion to using grease on anything!

 

Ironic - Sumo-King grease pump from Osaka, Japan (but "made in Taiwan"). 

 

 

[Dr D 21]

Thanks both, it had been dealer services up to this point (28k) so the cap should have been out at least once !!!!. Yes I best get some sumo grease on order. She is all serviced now, valve clearance ok, new fork oil, tyres, coolant change, brake fluid change, swing arm out and suspension greased. That should set it up for this year's commuting. I now know that everything comes appart. Even though the book was fully stamped I think some of them may have been fly by services.

[Steve Case 939]

You took the forks and swingarm out? Blimey thats commitment, hats off to you my friend.

All the best and happy commuting.

[outrunner 4,457]

5 hours ago, Steve Case said:

You took the forks and swingarm out? Blimey thats commitment, hats off to you my friend.

All the best and happy commuting.

That is something I do once a year to grease all the suspension bearings, I also do the centre stand spindle and change fork oil every 2 years.

 

Andy.

[TartanX 12]

I’ve just come across the same issue trying to get the cap off. Who ever has had a go at it before has already started to round off the edges so that the 10mm Allen Key is bit too slack. I’ve tried packing with a combination of rubber packing and grinding paste ( a bit heath robinson I know ) but to no avail . The cap is tight as hell and I’m frightened to put much more pressure on the key for fear it will really round off . Any other suggestions before I totally bugger it ? 
I’ve been soaking cap in penetrating oil for about a week. Been tapping it to try and loosen whilst attempting to turn it. Would use of a heat gun on the area be worth a shot do you think ? 
Appreciate any advice further to those listed above. Cheers 

[shiggsy 529]

Buy a replacement cap and then use a hammer and punch to drift the old one off.

[Slowboy 20,345]

11 hours ago, shiggsy said:

Buy a replacement cap and then use a hammer and punch to drift the old one off.

That’s what I had to do with mine, having done all the other things with release agent (Halfords shock and release) and heat.

[TartanX 12]

Yep ,ended up having to butcher it to get it off. My god it was tight. Had to take the grinder to cut couple of slots in it and hammered it slack with my trusty chisel. Very poor design and whomever had tightened mine previously were obviously a lot stronger than they thought.