850 Engine Build Help Please

Status
Not open for further replies.
Joined
Nov 11, 2008
Messages
834
Country flag
Hi all,

I'm building up an 850 engine and have a couple of final points that are of concern. I'd be thankful of some help from the brains trust:

1. Crank thrust washer - Presumably to set the crank end float. I see it in the parts diagram, but not mentioned in the assembly steps and nothing in the parts bin that looks even remotely like it. (It's a BIG shim - pretty easy to spot.) End float measured with dial gauge and confirmed with vernier calipers is a whisker under 14 thou. Limit is 15 thou.
Should I be concerned?

2. Points lead sealing - Where's the seal for this cable? Can't find anything in the parts diagram or the supplied gasket /seal kit.
Is there one (grommet/seal)?

Any and all advice appreciated.
Dave.
 
0.014" is not worth worrying about being within the factory spec and surprised it is that low so maybe has a shim from the past.
That cable I thought simply had a sheath around it at the timing cover area for it.
 
Hi all,
2. Points lead sealing - Where's the seal for this cable? Can't find anything in the parts diagram or the supplied gasket /seal kit.
Is there one (grommet/seal)?

Any and all advice appreciated.
Dave.
#17

 
End float measured with dial gauge and confirmed with vernier calipers is a whisker under 14 thou. Limit is 15 thou.
Should I be concerned?

No, as the factory increased the end float specification to 0.010" - 0.024" when they began fitting two roller main bearings from late '71('2' series serial numbers) but the information didn't make it into the workshop manual until 850 Mk3 (below).
850 Engine Build Help Please
 
Thanks guys,

I'll leave it as is. Just a momentary panic there.
The points lead - I've just run some thin tube all the way through the wire hole - it's a very snug fit - and then ran the cable through the tube. Funny the seal is not included in the full gasket set though.

Thanks again,
D.
 
Thanks guys,

I'll leave it as is. Just a momentary panic there.
The points lead - I've just run some thin tube all the way through the wire hole - it's a very snug fit - and then ran the cable through the tube. Funny the seal is not included in the full gasket set though.

Thanks again,
D.
Bought my first Commando in 1974, wasn't aware that seal existed until today!
 
Thanks guys,

I'll leave it as is. Just a momentary panic there.
The points lead - I've just run some thin tube all the way through the wire hole - it's a very snug fit - and then ran the cable through the tube. Funny the seal is not included in the full gasket set though.

Thanks again,
D.
What seal do you mean? The points wire just needs to be insulated from the housing just to help minimise chaffing
And sealed enough to stop the ingress of road dirt
I generally squirt a bit of silicone in with the wire
 
Remind those wires need some slack inside the point cover , to allow the engine moving up/down with isolastic , so a free in the hole wire is not a bad thing
 
Remind those wires need some slack inside the point cover , to allow the engine moving up/down with isolastic , so a free in the hole wire is not a bad thing
Would it not be best to allow for that movement before the wire enters the engine, perhaps, so that the wire/points interface is constant and not subject to external movement and possible stress?
Possibly?
 
Thanks guys,

I'll leave it as is. Just a momentary panic there.
The points lead - I've just run some thin tube all the way through the wire hole - it's a very snug fit - and then ran the cable through the tube. Funny the seal is not included in the full gasket set though.

Thanks again,
D.
I use RTV, then a lazy loop for engine movement before tying it to the frame. JMWO
 
2. Points lead sealing - Where's the seal for this cable? Can't find anything in the parts diagram or the supplied gasket /seal kit.
Is there one (grommet/seal)?
Post #3 hit it on the head. Part # 17 listed.
Cheers,
Tom
 
Status
Not open for further replies.
Back
Top