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Discussion Starter · #1 ·
A simple replacement of a damaged plastic cap on my left crankcase cover is turning into a nightmare.
First of all, does anyone know how to remove the larger silver plastic cap in this picture without scratching or damaging the paint on the left crankcase cover?
I've tried just about everything I can think of and it just won't budge. Worse, I'm starting to damage it. The replacement cap definitely has threads and screws in, but even the tools I'm using that fit the slot perfectly just won't loosen the darn thing.



The cap is part is #7 in the diagram below (shown with a HEX slot, which would probably make things a lot easier. Unfortunately mine just has a straight concave slot on it like in the picture):



To make matters worse, I stupidly started to remove the crankcase cover itself (I know...what was I thinking?) until oil started dripping. I only lost about a half a cup before I was able to tighten the bolts up again, but now I'm thinking I'll probably have to drain the oil and replace the crankcase gasket now that it's been saturated with oil, right?
 

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To remove the plug, use a flat punch or chisel and spin it out. Stay in the slot as close to the edge as possible without risking hitting the opening on the case if you slip. Tap it with a hammer. Make sure you have a replacement.

That works for screws also. I used the technique to get this seized recessed screw out of a master cylinder without damaging the cover -



As far as the gasket goes - you are fine. Keep an eye on it, but just because you got oil on it doesn't mean you need to replace it.
 

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Interesting that the Honda parts fiche is now showing the two hex rather than slotted caps.

Here is some discussion we had a while back about the caps. Even the Honda technician had problems removing mine without damaging it.

To get your old cap off, it's necessary to get a tool with good, solid fit in the slot. I would try a large, thick steel washer. Ideally one that almost but doesn't quite fit. Then tap it to wedge it into the slot (I think the cap will be wrecked no matter what you do). Then get an adjustable crescent wrench and snug it up on the washer at 90 degress to the axis of rotation. Then, remove the cap by turning counter clockwise.

Replace cap and O-ring with a hex type. Note: the O-ring for the hex cap is different than the one for the slotted cap. It is thinner in cross-section I believe.
 

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Those timing caps (which are made of aluminum, not plastic) are very tight from the factory. As jkv357 posted, use a punch on the outer edge of the slot. A few solid taps with a hammer will break it loose.

Whether you replace it with the hex key style cap or the original slotted style cap, using some Anti-Seize compound on the threads which will make it easy to remove next time.

Hex key style cap & O-ring - 90087-HB5-000 CAP (30MM) $10.06 - 91305-KF0-003 O-RING (27X2) $1.96

Slotted style cap & O-ring - 90087-KPP-860 CAP (30MM) $3.67 - 91356-KGH-901 O-RING (30MM) $0.50
 

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anything disposable like that can be had
by any strong sharp edge [as excellent above]
even a good flat blade screwdriver..
if you hold the blade pressing down/way from
the job it cant jump out when you use impact
into the shaft from the other hand..

dont go for too narrow an angle on the shaft
as the impact downward with some angle
will break it.. not a bad idea to hit it
the other way [inward] a couple of times
first,, then take it out..

this type of minor challenge between you
and the thing, is also part of the 'fun'..

naturally you would first attempt to outwit it,
such as stichill's makeshift special tool...
 

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Discussion Starter · #7 ·
All great suggestions from the very folks I was hoping to hear from on the subject. Thank you all.
My 2011 CBR has been so reliable that I haven't had to do much wrenching on it other than oil changes and 2 fender eliminators in the past 5 years.
It seems that every screw and bolt has grown accustomed to not being disturbed and they balk at any attempt to remove them.
After finally solving a particularly recalcitrant bar end last week I was hoping such problems were not the norm, but indeed it seems that my CBR has become quite obstinate in it's advanced age.
I'm surprised that cap is actually aluminium, as it's the mildest form of the metal I've ever encountered and is shockingly prone to easy damage.
Alas, while the CBR is a great bike in many respects, the individual parts that make up it's greatness certainly tend to veer towards the cheap.
I'm sure all of your excellent suggestions will lead to my eventual victory over this $3.67 part from hell.
So before I start sounding even more like shisoshin here, I will simply thank you all again for your much-appreciated advice and suggestions and have at the beast.
I can't tell you enough what a pleasure it is and has been to be a member cbr250r.net since I purchased my 2011 CBR, where such great folks with excellent advice are just a mouse-click away when you need them.
 

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Discussion Starter · #8 ·
SUCCESS!!
Thanks so much for the suggestions to use a small chisel and hammer on the outside edge of the cap's slot.
After a few taps the cap began to move and I was able to unscrew it and install it's replacement (adding some Loctite anti-sieze compound on the threads of the new one as Mike suggested) with no damage at all to the crankcase cover.
I'll be ordering one with a HEX key during my next parts order session, keeping the slotted one as a spare since it's so easy to damage these things.
Hoping good karma deservedly comes your way soon my friends.
You guys are the BEST!
 

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I've had these [email protected] CAPs for over ten years, the first time I did significant damage to one of them (the 30mm cap), and that was also the last time I bought them. I don't know if the ones with hex solves the problem, I don't think so. Greasing doesn't solve the all problem either. It's not that the metals stick (Aluminum to Aluminum, it can happen, but here this is not the case). Because the threads screw is fine, the pitch is small, and the O-ring creates a pre-load, so it is very easy to lock these CAPs, this is a classic friction lock. So now I have a "special technological A tiny 'socket' hole" on my caps, a hole that was created the first time I used a punch tool, which it's easily helps to open the caps, and the problem is gone.
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That pick axe looks brutal to use to open this small cap, Tamir, but it seems like that’s what it it takes.

I bought a replacement cap and gasket earlier because my cap was damaged, but I failed to get it loose and ended up scratching my crankcase cover. Real bummer, I gave up after that.
 

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That pick axe looks brutal
Yes it's a bit brutal, but it's effective.
Some say that changing to a cap with a hexagonal socket gives a more elegant solution
These grooves are not good.
I bought a replacement cap and gasket earlier because my cap was damaged, but I failed to get it loose and ended up scratching my crankcase cover. Real bummer, I gave up after that.
Yes, after the first time(I bought NEW), about ten years ago, I adopted the solution with the punch tool , and since then I no longer change these caps.
 
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