Engine fit/frame clearances? oil leak

[hoogerbooger]

last check before I decide to remove the timing cover ( on my B40F)...or not. I now know that I should be able to replace the kick-start oil seal and the LT lead grommet without removing the cover.

However, when I wrap up the kick start seal in paper towel to stop that leak running....I still get oil accumulating over night at the lowest point on the mating faces of the inner timing case & cover ( see picture) So I believe I have a case leak here.

As well as being the lowest point, it is the closest to the frame at only 0.15mm. And sand/grit was lodged there fairly solidly. However, at this closeness is vibration going to be an inherent difficulty to getting a seal? Should the engine be that close to the frame here?
 

[hoogerbooger]

BUMP

still looking for advice on this. Is anyone else willing to look at/measure the clearance to the frame at this location on their B40/C15 ?

I've just noticed the rear engine lug looks a mess. According to Rupert unworn parallel sides on the alluminium lug is what's needed to prevent movement......not cranking up the torque on the mounting bolt.....so not much I can do here.....however, wondering if this related to my very close clearance to the frame.....i.e may have ovalised bolt hole in the lug as well as worn sides...and the engine is sitting a bit lower??

[DAVE BRADY]

Hi,

Not had a B40 for a while but I do not remember the case being that close to the frame.
Try slackening off the engine bolts and see how much vertical movement there is.  This will at least give an indication of the amount of wear. As well as some wear in the softer cases there could well be some in the frame holes and on the bolts.

Dave.

[hoogerbooger]

OK had a look and will probably have a go. But I'm still interested if anyone can tell me how much clearance from the frame they have.

On checking, the rear mounting bolt wasn't obviously loose, but was fairly easy to tighten up a pinch.....so may be loose enough to move with vibration. I can use a jack and a block of wood  under lower engine mounting area, loosen all bolts and see if the engine will go up a bit.....Will see.....but it may be that the misshapen aluminium rear mounting lug is not going to help it stay in place with vibration...but at least I'll have identified an issue and potential cause of the outer timing case leak.

Now is there any guidance on tightening the engine mountings? Can they be too tightly done ?

[hoogerbooger]

Well, I loosened all mounting and head-steady bolts, with a jack and a block of wood under the engine. Jacked it a bit and rocked the bike a bit on the jack...then re-measured the clearance to frame.

Before = 0.15mm
On jack bolts loose = 0.65mm
Bolts re- tightened whilst on jack/now = 0.35mm

Still dam close to the frame.

If you look at the photo above you can see that the outer- timing cases is larger- forming a lip, the lip being the nearest bit to the frame.

As it looks like the cover will be coming off I'm wondering if I should remove some of that lip to gain more clearance. Probably double the gap or more.

Any views ? sensible or daft idea?

Would be very grateful if any B40 or C15 owner (with a non-leaking outer timing case) is willing to measure how much gap they have to the frame below the kick-start)

[Tigerfeet]

My C15 project engine was tight on the frame. When I took the engine out I found that the spacer washer on the bottom engine mount was missing, and not only had this made the engine align differently, but in tightening the bottom bolt with the spacer washer missing, the preveious owner had bent the frame rails. (A threaded rod with some nuts and big washere soon put that right.) 

[hoogerbooger]

Thanks Tigerfeet. Yes, also read this as a common frame issue in RR.....but then rushed to check and I do have the offside spacer.

As far as I can work out my spacer appears to be the correct width for a B40, although the parts catalogue doesn't actually give a size. Online the part 41-4036 can be found at 13.9mm. I measure just over 14mm i.e 9/16" in old money.

Would be interested to know what clearance you ended up with on the C15

[Tigerfeet]

I'll let you know - once I get it fitted...  A big step forward would be getting the parts back from the engineer who is installing and line reaming the camshaft bushes...