Engine change?

[Sgt Bilco]

Just going to have the heads off the old girl to check the valve guides as she blows a bit of smoke on start up occasionally. It's not a major issue really but she'll be doing some more big mileage over the next couple of years so needs doing. There is a chance it may be something more serious which could get pricey so the thought hit me that it may be almost worth dropping a second hand motor in as they are pretty cheap if we find anything untoward.

I then wondered whether a twin cam motor would fit in an older GSA. They can't be that different so anyone have an idea?

 

[Micky]

So how does this affect the 200,000 mile challenge

 

[RedRick Esq.]

So how does this affect the 200,000 mile challenge

Triggers broom springs to mind !

Beer soon ?

 

[Pukmeister]

My guess is that although similar, you'd probably run into other issues such as fuelling or ecu compatibility. The engine management might use different sensors for crank or cam angle between the two types, or handle the data from them differently. I guess a long boring trawl through the MaxBMW Fiche site comparing sensor part numbers might give a better insight if you are serious about it. The nuts and bolts of fitting the lump itself can't be much different, if at all.

Why not just source a set of used low(er) mileage heads for your bike and do a straight swap? You'd be sorted again very quickly and easily.

 

[Sgt Bilco]

So how does this affect the 200,000 mile challenge

I won't be changing the motor Micky but I was just wondering.......like you do so I thought I throw the question out to the masses. The motor is really good but occasionally just blows a wee bit of blue smoke on start up when hot. It's done it for a few years and although it doesn't bother me, and I don't thing anything serious is amiss, people parked behind can get a bit pissed off.

I've planned the 200k mark for the end of 2017 (on the original motor).

 

[Pukmeister]

I've planned the 200k mark for the end of 2017 (on the original motor).

 

[er-minio]

I then wondered whether a twin cam motor would fit in an older GSA. They can't be that different so anyone have an idea?

I think I've seen a thread about a (functioning) twin cam motor in an older GS on another forum I'm on.
I'll see if I can fish out the thread.

 

[Micky]

I won't be changing the motor Micky ......

I've planned the 200k mark for the end of 2017 (on the original motor).

Then I'm looking to beat ya

 

[er-minio]

These are the pics from the thread.
Forum is in italian, so little use here.

Basically the guy claims he removed the old engine on his 2009 GS and installed a twin cam engine + throttle bodies coming from an RT.
He mantained the original exhaust (no flappy valve).
He stated that he is still using the ECU from the older engine, and this sounds strange to me, my limited experience in messing with the Laser chips on the 1150s was that you get completely dead engine or fuel pump forever running when you switch on the ignition if you fuck something up (single spark chip on twin spark engine, etc).

Anyway, my mechanical knowledge is pretty limited if not non-existent... so don't shoot the messenger.

Original engine:

Twin cam engine:

Bike:

Reassembled:

 

[Micky]

Triggers broom springs to mind !

Beer soon ?

Ha ha .... five new handles and fifteen new brush heads

Beer soon? M'in the Tut'n Shive (Doncaster) tomorrow (Wednesday) at five with the lads .... otherwise before Christmas at Wadworth

 

[Steptoe]

Just going to have the heads off the old girl to check the valve guides as she blows a bit of smoke on start up occasionally. It's not a major issue really but she'll be doing some more big mileage over the next couple of years so needs doing. There is a chance it may be something more serious which could get pricey so the thought hit me that it may be almost worth dropping a second hand motor in as they are pretty cheap if we find anything untoward.

I then wondered whether a twin cam motor would fit in an older GSA. They can't be that different so anyone have an idea?

New exhaust valves, guides and guide seals. Maybe drop in some exhaust valve seats while you're at it.

Currently doing the same on a customers 1200..

 

[Deleted account 181015003]

I won't be changing the motor Micky but I was just wondering.......like you do so I thought I throw the question out to the masses. The motor is really good but occasionally just blows a wee bit of blue smoke on start up when hot. It's done it for a few years and although it doesn't bother me, and I don't thing anything serious is amiss, people parked behind can get a bit pissed off.

I've planned the 200k mark for the end of 2017 (on the original motor).

If that's all its doing just run it as it is, the worst that can happen is it will use some oil. Try parking it on the centre stand as much as possible and it should reduce the start up smoke.

 

[Flipfly]

These are the pics from the thread.
Forum is in italian, so little use here.

Basically the guy claims he removed the old engine on his 2009 GS and installed a twin cam engine + throttle bodies coming from an RT.
He mantained the original exhaust (no flappy valve).
He stated that he is still using the ECU from the older engine, and this sounds strange to me, my limited experience in messing with the Laser chips on the 1150s was that you get completely dead engine or fuel pump forever running when you switch on the ignition if you fuck something up (single spark chip on twin spark engine, etc).

Anyway, my mechanical knowledge is pretty limited if not non-existent... so don't shoot the messenger.

No surprise with your 1150 experience as the single and twin spark are programmed differently due to the extra plugs.

The single cam and twin cam both run twin plugs and I would guess similar mapping (maybe within the ranges of control offered by the lamda sensor).

I reckon it'd be a relatively simple thing to do.

Chances are Chris that it just needs rings and maybe the valve seats

Edit, beaten by the guru

 

[chrisjk]

I would have thought piston seals or worn valve guides as likely possible causes for the smoke in the exhaust.

 

[er-minio]

No surprise with your 1150 experience as the single and twin spark are programmed differently due to the extra plugs.

Yep.

The single cam and twin cam both run twin plugs

Initially when that thread came out, the only twin cam engine I had available to have a look at was the one on my HP. And the HP engine is single spark. So I was a little confused.
I didn't know that twin cam GS/RTs are still twin spark.

Then, I also assumed there were other different things in the electronics. I was probably wrong.

and I would guess similar mapping (maybe within the ranges of control offered by the lamda sensor).

Yes.

 

[Sgt Bilco]

New exhaust valves, guides and guide seals. Maybe drop in some exhaust valve seats while you're at it.

Currently doing the same on a customers 1200..

That's what Mikeyboy will do and it should cure the issue. All the guru's I've spoken to agree with this reason. As I've said, it's running well, I'm not over concerned and I could leave it but when I'm on a trip, it doesn't do to have the tour guides bike smoking like a burning Messerschmidt. Might as well bite the bullet.

 

[Greenman14]

Compression test is OK? If this is the case maybe the problem isn't too severe. If the heads are off it might be worth a new set of rings, but where do you stop?

 

[Pukmeister]

Compression test is OK? If this is the case maybe the problem isn't too severe. If the heads are off it might be worth a new set of rings, but where do you stop?

New rings means glaze busting the bores to allow bedding in.

Aren't these barrels Nickasil coated ?

Probably cause more harm than good fitting new rings to worn bores, with or without breaking the glaze.

 

[Flipfly]

New rings means glaze busting the bores to allow bedding in.

Aren't these barrels Nickasil coated ?

Probably cause more harm than good fitting new rings to worn bores, with or without breaking the glaze.

If the bores are anything like previous incarnations of GS, the bore will be like new. The cylinders usually still show the honing marks. I'd not worry about fitting new rings to a GS.

 

[Shunt]

That's what Mikeyboy will do and it should cure the issue. All the guru's I've spoken to agree with this reason. As I've said, it's running well, I'm not over concerned and I could leave it but when I'm on a trip, it doesn't do to have the tour guides bike smoking like a burning Messerschmidt. Might as well bite the bullet.

Id of thought it'd be a great idea, Leave a blazing smoke trail, No one can winge that that they couldn't see where you went,