Springs and how important they are.
This has to start with a bit of history.
My daily comuter is a 1982 GPz1100, which now sports 148000km.
On the way home from AMID this year, it lost power and after much
searching, I found it had burnt a valve. The cause of the burnt
valve proved to be carbon buildup resulting from exessive oil usage.
So yes I have a 30 year old high mileage Jap bike that uses oil.
That gave me 2 options :
1. Rebuild the topend...approx R12000.
2. Drop in a used motor...approx R5k - R6k
2 weeks ago I saw an advert on Gumtree for the parts I needed.
Ended up I did a trip to Lichtenburg on Saturday to collect these parts..
And thats where my story begins.......
Saturday morning 06:00 leave Pretoria with half a tank of fuel.
Stop in Ventersdorp to fill up and notice a ticking from the right
cylinder and the bike is hardly idling. From 2500prm is perfect, but below
that its very erratic. I decide that since its ok above 2500, I'll push on.
Get to Lichtenburg, do the deal, load my new barrels, pistons, rings and head
into my panniers, and head for home.
After an uneventful trip further, arrive home just before 12:00.
Have a munchie and decide to look for the source of my poor idling.
Do some basic checks, cables, leaks, connections etc, all looks OK.
Check TPS, its a bit eratic, so I jumped in with a dremel and openned it
up. Cleaned it all out, sealed it and put it back. Its more consistant, but idling still
all over the place.
Disconnect the lambda sensor, same issue. Start messing around with plugs, stick coils
etc and decide that I may have a dodgy plug.
Sunday morning I buy 4 new plugs (R270) and fit them.....problem still there.
By now the ticking on the right cylinder is irritating so I decide to dive in and
address this while I'm busy, so off with the valve cover...and this is what
I was presented with..
That was enough for me for the day, so tonight I pulled the head to assess
if there is any further damage.Theres something mildly intoxicating in popping off
the head of a bike thats done 95000km and it looks like it hasnt seen 10000.
I'll have to lightly lap the valve in and put it back together.
I've done some trawling around the web and have not seen this reported anywhere else.
So is this a first ? Anyone heard of this before, and most importantly, does anyone
have a spare knocking around. I havent checked, but I'm not hopefull that BMW is going to
have any of these floating around.
Oh and I'm extremely happy with BMW for the way the collets fit into the retainers, preventing
a nasty valve drop incident, which would have been rather inconvenient and expensive to repair.
This has to start with a bit of history.
My daily comuter is a 1982 GPz1100, which now sports 148000km.
On the way home from AMID this year, it lost power and after much
searching, I found it had burnt a valve. The cause of the burnt
valve proved to be carbon buildup resulting from exessive oil usage.
So yes I have a 30 year old high mileage Jap bike that uses oil.
That gave me 2 options :
1. Rebuild the topend...approx R12000.
2. Drop in a used motor...approx R5k - R6k
2 weeks ago I saw an advert on Gumtree for the parts I needed.
Ended up I did a trip to Lichtenburg on Saturday to collect these parts..
And thats where my story begins.......
Saturday morning 06:00 leave Pretoria with half a tank of fuel.
Stop in Ventersdorp to fill up and notice a ticking from the right
cylinder and the bike is hardly idling. From 2500prm is perfect, but below
that its very erratic. I decide that since its ok above 2500, I'll push on.
Get to Lichtenburg, do the deal, load my new barrels, pistons, rings and head
into my panniers, and head for home.
After an uneventful trip further, arrive home just before 12:00.
Have a munchie and decide to look for the source of my poor idling.
Do some basic checks, cables, leaks, connections etc, all looks OK.
Check TPS, its a bit eratic, so I jumped in with a dremel and openned it
up. Cleaned it all out, sealed it and put it back. Its more consistant, but idling still
all over the place.
Disconnect the lambda sensor, same issue. Start messing around with plugs, stick coils
etc and decide that I may have a dodgy plug.
Sunday morning I buy 4 new plugs (R270) and fit them.....problem still there.
By now the ticking on the right cylinder is irritating so I decide to dive in and
address this while I'm busy, so off with the valve cover...and this is what
I was presented with..
That was enough for me for the day, so tonight I pulled the head to assess
if there is any further damage.Theres something mildly intoxicating in popping off
the head of a bike thats done 95000km and it looks like it hasnt seen 10000.
I'll have to lightly lap the valve in and put it back together.
I've done some trawling around the web and have not seen this reported anywhere else.
So is this a first ? Anyone heard of this before, and most importantly, does anyone
have a spare knocking around. I havent checked, but I'm not hopefull that BMW is going to
have any of these floating around.
Oh and I'm extremely happy with BMW for the way the collets fit into the retainers, preventing
a nasty valve drop incident, which would have been rather inconvenient and expensive to repair.
