help no compression !

[Johnwhit]

went out today on the way home at about 70mph it started making a pinking noise when I opened the throttle. it then started lacking power & died on the right cyl. rode it the last few miles home on one cyl and swapped the plug /injector to see if it swaps onto the other cyc. it wasnt making any scary engine noises on the way either
I then checked the compression and its not registering any preasure on the right pot.
I took the tapet cover off and cranked it over and everything looks ok - so its not a broken cam chain.

the sparkplug isnt covered in oil and I stuck as to what to do next.
I need the bike running and havnt much cash to throw around....I'm realy stuck now.
any suggestions on what to do next ? I'm in worcester so if anyone knows of a local good honest Steptoe and ideas on what's up & an idea on cost ?
cheers
John (1150gs 41000mls 2002)

 

[Steptoe]

It sounds like you've damaged a valve. I see a few, but funnily mostly RT's.

Usually no other damage ( unless your very unlucky), so cost of parts are a valve ( or two) and a headgasket.

 

[Johnwhit]

thanks for the reply steptoe.
I wish you were at our end of the world.
when I have calmed down I may pull the head & have a look, nver pulled a head off a bike before but I shold be able to sort it.

anyone know of someone in woecester area that could look at it for a reasonable price ?

cheers again Steppers -- im starting to calm down a bit now!!!

 

[Steptoe]

, nver pulled a head off a bike before but I shold be able to sort it.

!

Here's a [URL="http://www.ukgser.com/forums/showthread.php?t=93209"]GUIDE[/URL]

 

[Deleted account 240901001]

..anyone know of someone in woecester area that could look at it for a reasonable price ?

!

Genesis motorcycles..Sanders lane/road (?) Bromsgrove. Top notch outfit.

 

[TJ]

thanks for the reply steptoe.
I wish you were at our end of the world.
when I have calmed down I may pull the head & have a look, nver pulled a head off a bike before but I shold be able to sort it.

anyone know of someone in woecester area that could look at it for a reasonable price ?

cheers again Steppers -- im starting to calm down a bit now!!!

I had the same problem last year in Italy only on the left side.
No other damage so I guess I was lucky.
Got the bike up to Steve (Motoscot) in Luton, all done in a couple of days and very reasonably priced too. He's on the site if you do a search.

HTH

 

[Johnwhit]

took the exhaust off to see if I could look at the valve and the exhaust ones look carboned up but from what I can see with a torch & turning the motor over to watch them open & close I cant see amy obvoius damage but I can only see part of it.

when turning it over on the starter i feel the bottom exhaust valve blowing the air back out as it come up to compression so that is deffenitly the culprit.

my question is could if be carbon stopping it seal & can I get away with spraying something into the exhaust port to clear it us or am I off my head & it needs the head pulling ?

if I do I take it I need (ontop of my standard socket set) a 5mm & 8 mm allen to fit onto my wrench ?
do I need to get those torque allen keys or can the valves be removed with out taking that bit off...
& do I need to lap the valves when I put them in with grinding paste..

sorry for amm the questions dudes but if I need to pull the head I need all the advice I can get


cheers
John

 

[sockpuppet]

The allen sockets are cheap. Few quid off ebay, For £15 i got a sealey set with more torx, allen and spline drives to shake a stick at.

 

[ciderman gs]

pull the head and drop the valves if the seats are not pitted and your valve is just carboned wire brush the valve and lap in with paste and you should get away with it.

 

[Matt Padgham]

I,ve just had a very similar experience. Travelling back home, about 65 miles away, engine suddenly starts to lose power and running very rough almost as if on one cylinder. Got home OK, running very rich from the looks of the exhaust, will not tick over under 2000 rpm and is pinking.
Bike's a 98 r1100gs, 57000 miles. Same conclusion of broken valve - what do you think?

 

[Johnwhit]

doesnt sound the same , mine didnt show any clue of running rich as the constantly open valve stoped it sucking in air/fuel, but i'm a bit clueless

try what i did first , swap the plugs / then injectors over to see if it swaps sides. i also looked inside the throttle body and saw it was pumping out a fuel mist so that may give you a clue.

what also made me know it was machanical was the lack of compression on the down pot. I took the other side plug out and cranked it over a few times and its easy then to tell if it has compression, if you have access to a compression tester that will tell you straight away.

i'm stripping mine tomorrow and will post for help as I go along
cheers
John

 

[Johnwhit]

forgot to say,
get it running at a steady rpm & pull an injector connector off at a time. on the side that it keeps running as if you havnt remove will show what side it is.
dont rely on the exhaust hot test as mine was hot both sides when I got home (ouch) but the injector plug proved one cyl wasnt working at all

 

[littleredrooster]

I,ve just had a very similar experience. Travelling back home, about 65 miles away, engine suddenly starts to lose power and running very rough almost as if on one cylinder. Got home OK, running very rich from the looks of the exhaust, will not tick over under 2000 rpm and is pinking.
Bike's a 98 r1100gs, 57000 miles. Same conclusion of broken valve - what do you think?

If it's pinking, it can't be a broken valve.

Broken valve = no compression = no pre-ignition.

Could be the noise of the broken bits rattling around the pot, however.....

 

[Johnwhit]

well I took the head off and found the exhaust valve broken
im hoping the liner is ok, dont want to try take it off tdc for a look with the cable tie clamping the cam gear to the chain. I'm just going to pray its fine !

anyway ill be putting an order in the morn for two exhaust valves. dont think its worth doing the inlet at the same time (bit broke or am I being foolish & should do all 4 ??)

only question is head bolts , the book says tighten all nuts to 20nm then 90deg - is that saying do the four head bolts to this torque then an additional 1/4 turn ?

cheers dudes
John

 

[TJ]

well I took the head off and found the exhaust valve broken
im hoping the liner is ok, dont want to try take it off tdc for a look with the cable tie clamping the cam gear to the chain. I'm just going to pray its fine !

anyway ill be putting an order in the morn for two exhaust valves. £75 each...when mine was done...dont think its worth doing the inlet at the same time (bit broke or am I being foolish & should do all 4 ??)

cheers dudes
John

Almost the same as mine John.

Wouldn't mind knowing why it happens..Lets hope your lucky and no other damage.

 

[Johnwhit]

dudes,
the exhaust valves cost more that I thought,
whats the thinking on only replacing the damaged valve or should i spend another £85 & get two exhaust valves.

am i being silly getting just one valve and just lapping the seat on the other ?

i will place my order later this morning , (help Streptoe - what do you suggest?)

cheers & thanks
John

 

[MattW]

well I took the head off and found the exhaust valve broken
im hoping the liner is ok, dont want to try take it off tdc for a look with the cable tie clamping the cam gear to the chain. I'm just going to pray its fine !

anyway ill be putting an order in the morn for two exhaust valves. dont think its worth doing the inlet at the same time (bit broke or am I being foolish & should do all 4 ??)

only question is head bolts , the book says tighten all nuts to 20nm then 90deg - is that saying do the four head bolts to this torque then an additional 1/4 turn ?

cheers dudes
John

It'll have started with a tiny little burn on the valve which overheats it and slowly erodes it away. Hopefully it just blew the broken bits out of the exhaust port. When you reassemble, I might be inclined to bolt it back together 'loose', rotate to BDC and pull the head again to check the liner.

I know it costs, but in your case I'd be inclined to get two new valves. They don't fail for no reason and it looks like yours has run hot (it'll be worth doing some investigation on this eventually) which will have probably stressed the other valve. Also check the exhaust valve seats very carefully (especially the one with the failed valve) - if they're burned at all, I'd consider getting them recut or even changed - you can't lap out damage like that - you'll end up bu**ering your new valve. This is an engineering shop job unfortunately....

 

[Number 6]

only question is head bolts , the book says tighten all nuts to 20nm then 90deg - is that saying do the four head bolts to this torque then an additional 1/4 turn ?

Yes.

re the other valve, pull it out and look at the face where it sits on the valve seat. If there's any sign of damage then replace it, if it's ok then just pop it back in. If there's no sign of damage to the top of the piston then the cylinders probably ok. Put it all back together, run it for a while and then do a compression check.

 

[littleredrooster]

You're almost certainly going to have to re-cut and regrind the seats after fitting new valves, otherwise you'll be back to square one in a very short mileage.

 

[MattW]

Just thought:
Remember to order a new head gasket if you haven't already - you can't reuse the old ones (especially an original pattern '94 one).