M900 Engine help - Page 2

Davy · 09-02-2017, 08:26 PM

Last pic. Do the valve heads look ok? One of the studs has been replace with a black one at some point, should I leave it or replace all 8

Dukedesmo · 09-02-2017, 08:46 PM

At least there's a decent amount of stud left to grab hold of. It's when they break off flush with the case that you've got problems.

And, they are the pesky silver studs...

Dukedesmo · 09-02-2017, 08:55 PM

Assuming it was working OK before then the valves are likely OK.

That said and given the bike is likely 20 years old, the heads and valves could do with a refresh; clean, check the guides & seats etc. but it involves removing the valves/shims etc. which is fine if you're into that sort of thing? (I'd have to as I couldn't leave it alone) but it all depends on how far you want or are capable of going?

Davy · 09-02-2017, 09:24 PM

It was running sweet before, it's actually a well serviced bike. I'll post more when/if I get the studs out..

Davy · 11-02-2017, 01:56 PM

Davy · 11-02-2017, 01:57 PM

Davy · 11-02-2017, 01:59 PM

Davy · 11-02-2017, 02:00 PM

Davy · 11-02-2017, 02:07 PM

Well that was nearly to easy. Lock nuts locked on and just screwed them off with the shifter NO heat,No damaged threads.
Took the grinder to the broken one and grinder two flat sides put the shifter on and bingo.cleaned the threads out. Threadlock on the new ones 2hours all done.

Albie · 11-02-2017, 05:04 PM

That's good to know

Dukedesmo · 11-02-2017, 05:18 PM

Nice one!

Especially because some have had a right bastid of a job shifting them, involving; swearing, pain, tears, breakage and spark erosion.

Whilst it's apart, see if you can see the oil gallery plug in the side of the crank as they can back out, hopefully and probably it'll be fine but it costs nothing to look down the side of the crank with a bright light.

On reassembly make sure you fit all new 'O' rings in the cylinders/heads and seat the base gaskets with threebond (but not too much or you might block some oilways).

Davy · 11-02-2017, 06:07 PM

The base gasket? Is that the metal shim you talked about? should I coat both sides of it then bolt the head down on that? Or just seat it as you said.
The oil gallery plug. Is it best looking for it through the horizontal/bottom cylinder at the crank, which side is it on right/left?

Dukedesmo · 11-02-2017, 10:23 PM

Quote:

Originally Posted by Davy

The base gasket? Is that the metal shim you talked about? should I coat both sides of it then bolt the head down on that? Or just seat it as you said.
The oil gallery plug. Is it best looking for it through the horizontal/bottom cylinder at the crank, which side is it on right/left?

Yes the shim, if it's still good (not kinked) then re-use with a thin coating of threebond on both sides (better than the hard red stuff they used back when it was built) but make sure you don't block the small oil feed hole that passes through on the RH side of the cylinders.

As for the oil plug, you should just be able to see it (or the hole it's in) on the left side of the crank, through the vertical cylinder hole.

Here's what it looks like, the big screw in the side of the crank;

Obviously you won't see it like that, in fact you might not be able to see it, only the hole it sits in and that's a good thing because if it works it's way out so that it's protruding from the crank (and rubbing on the bearings) then you have a problem but if it's flush or under then it's fine. From what I've heard if they haven't come out by a certain mileage then they won't.

This is how it should look (under the grubscrew);

You'll almost certainly be OK but you wouldn't want to put it back together if it's backing out because the engine won't last long if it does.

Also clean up the head to cylinder faces as much as possible where they meet because there are no gaskets so you want a nice fit, you can use a bit of fine valve grinding paste and 'wiggle' the head back and forth as much as it will to 'polish' the faces (clean off afterwards) so you have as good a chance as possible (with all new 'O' rings) of a leak-free head.

Davy · 12-02-2017, 08:48 AM

Had a real good look last night and all seems fine. I did check the strainer and it was clean too

Davy · 19-02-2017, 10:33 AM

Ok . So I'm at the stage where I'm ready to re-assemble the barrels and heads. I've got all my new seals and a tube of three bond,I've meticulously cleaned every mating surface.
So looking on line last night for torque setting. Is there a certain method to follow, or are they torqued up in stages. What to you guys do

09-02-2017, 08:26 PM	#16
Davy Registered User Join Date: Aug 2007 Location: Derry Bike: M900 Posts: 358	Last pic. Do the valve heads look ok? One of the studs has been replace with a black one at some point, should I leave it or replace all 8 __________________ 1994 M900 Black

09-02-2017, 08:46 PM	#17
Dukedesmo Registered User Join Date: Sep 2010 Location: Leics Bike: M900 Posts: 2,842	At least there's a decent amount of stud left to grab hold of. It's when they break off flush with the case that you've got problems. And, they are the pesky silver studs... __________________ M900, 916, LeMans II.

09-02-2017, 08:55 PM	#18
Dukedesmo Registered User Join Date: Sep 2010 Location: Leics Bike: M900 Posts: 2,842	Assuming it was working OK before then the valves are likely OK. That said and given the bike is likely 20 years old, the heads and valves could do with a refresh; clean, check the guides & seats etc. but it involves removing the valves/shims etc. which is fine if you're into that sort of thing? (I'd have to as I couldn't leave it alone) but it all depends on how far you want or are capable of going? __________________ M900, 916, LeMans II.

09-02-2017, 09:24 PM	#19
Davy Registered User Join Date: Aug 2007 Location: Derry Bike: M900 Posts: 358	It was running sweet before, it's actually a well serviced bike. I'll post more when/if I get the studs out.. __________________ 1994 M900 Black

11-02-2017, 01:56 PM	#20
Davy Registered User Join Date: Aug 2007 Location: Derry Bike: M900 Posts: 358	__________________ 1994 M900 Black

11-02-2017, 01:57 PM	#21
Davy Registered User Join Date: Aug 2007 Location: Derry Bike: M900 Posts: 358	__________________ 1994 M900 Black

11-02-2017, 01:59 PM	#22
Davy Registered User Join Date: Aug 2007 Location: Derry Bike: M900 Posts: 358	__________________ 1994 M900 Black

11-02-2017, 02:00 PM	#23
Davy Registered User Join Date: Aug 2007 Location: Derry Bike: M900 Posts: 358	__________________ 1994 M900 Black

11-02-2017, 02:07 PM	#24
Davy Registered User Join Date: Aug 2007 Location: Derry Bike: M900 Posts: 358	Well that was nearly to easy. Lock nuts locked on and just screwed them off with the shifter NO heat,No damaged threads. Took the grinder to the broken one and grinder two flat sides put the shifter on and bingo.cleaned the threads out. Threadlock on the new ones 2hours all done. __________________ 1994 M900 Black

11-02-2017, 05:04 PM	#25
Albie Fanactical volunteer Join Date: Oct 2003 Location: Kent Bike: M900 Posts: 9,030	That's good to know __________________ http://albies93m900.blogspot.co.uk/

11-02-2017, 05:18 PM	#26
Dukedesmo Registered User Join Date: Sep 2010 Location: Leics Bike: M900 Posts: 2,842	Nice one! Especially because some have had a right bastid of a job shifting them, involving; swearing, pain, tears, breakage and spark erosion. Whilst it's apart, see if you can see the oil gallery plug in the side of the crank as they can back out, hopefully and probably it'll be fine but it costs nothing to look down the side of the crank with a bright light. On reassembly make sure you fit all new 'O' rings in the cylinders/heads and seat the base gaskets with threebond (but not too much or you might block some oilways). __________________ M900, 916, LeMans II.

11-02-2017, 06:07 PM	#27
Davy Registered User Join Date: Aug 2007 Location: Derry Bike: M900 Posts: 358	The base gasket? Is that the metal shim you talked about? should I coat both sides of it then bolt the head down on that? Or just seat it as you said. The oil gallery plug. Is it best looking for it through the horizontal/bottom cylinder at the crank, which side is it on right/left? __________________ 1994 M900 Black

12-02-2017, 08:48 AM	#29
Davy Registered User Join Date: Aug 2007 Location: Derry Bike: M900 Posts: 358	Had a real good look last night and all seems fine. I did check the strainer and it was clean too __________________ 1994 M900 Black

19-02-2017, 10:33 AM	#30
Davy Registered User Join Date: Aug 2007 Location: Derry Bike: M900 Posts: 358	Ok . So I'm at the stage where I'm ready to re-assemble the barrels and heads. I've got all my new seals and a tube of three bond,I've meticulously cleaned every mating surface. So looking on line last night for torque setting. Is there a certain method to follow, or are they torqued up in stages. What to you guys do __________________ 1994 M900 Black