possible top end rebuild needed at 60k

march69 : Hello, Richard here 2002 Silverwing almost 60,000 miles. Bought it with 16,000 5yeara ago. What am I doing wrong? Mechanic says spark plugs were 'black '. 70 compression #1 cylinder, 130 #2 cylinder. Said valve adjustment might fix compression, otherwise it's a 'top rebuild'. Always change oil at 3K, keep good rubber in her and replace belt at factory intervals. I didn't realize (read the manual dumbass) that valves needed inspection every 8K. I was hoping to put 100-200k miles on her

The SW is a parallel twin, not a V, so there is no front and rear cylinder and the valve inspection is every 16k.
Are you sure he's talking about your bike?

steve_h80 wrote:

The SW is a parallel twin, not a V, so there is no front and rear cylinder and the valve inspection is every 16k.
Are you sure he's talking about your bike?

Forgive me. Cylinder #1 70psi cylinder #2 130psi. And thank you for the valve inspection 16k clarification. I guess I figured shops would check the valves when I've asked for a point to point inspection or when I have the belt changed which is also every 16K.

I hope the valve adjustment fixes the compression; with shim under bucket valves, the clearance closes up as the valve recedes into the head, which makes any valve noise quieter rather than louder. Eventually you get to a situation where the valves can't close and you lose compression, you also run the risk of burning a valve as it can't cool effectively.

The valves on the Swing are easy to check once the plastics (seat/footpegs/maintenance cover/engine cover) are removed, and the engine is easy to turn to the right position with the belt cover removed. Based on the design, I would not expect the clearance to change quickly as the Swing is low revving and the shim/bucket layout is usually very robust. The same layout is on my 09 ST1300 and that hasn't changed in 50,000km of running (I have checked it twice).

I'm not sure if anyone has had to do a top end rebuild on a SW. ????

Your problem is curious. A friend of mine once put Slick 50 oil additive in his Rover PI 3.5. Turned out to have 'gunged' and starved the top end of oil. I sometimes find my plugs a bit dark but new plugs and filter seems to fix it. It doesn't trouble me.

Terry's suggestion could be a good idea. Make the top end rebuild a last resort. Try a fuel system cleaner, it may get rid of any nasties lurking in there.

Hope you find a solution.

Cue the usual recommendations for a Seafoam enema.

My guess is the gunked up plug is a consequence of low compression leading to incomplete combustion, so nought to do with the fuel system.

In 17 years of Silverwing ownership and membership on all of the known english speaking Silverwing forums over that time, I’ve never heard of anyone needing a valve adjustment. 

But then it is possible that something unusual happened to cause your #1 cylinder to lose compression.

Please let us know how you get on with this problem. We all benefit from shared information.

What's Seafoam?  

My thoughts on a fuel cleaner were along the lines of burning off any carbon build-up on the valve seats.

"Durin' na wowar" we used to cane our engines to within a blow-up in order to clear the engine of carbon. Not sure if that would work on more modern engines but you never know.

Loosemarbles wrote:

"Durin' na wowar" we used to cane our engines to within a blow-up in order to clear the engine of carbon. Not sure if that would work on more modern engines but you never know.

Ah-ha! You mean an "Italian Tune-up"!

Well that made me laugh out loud.

I remember when engines were made entirely of cast iron.

Could be a tight valve but could be damaged by now.  Do a wet compression check add a little oil in each cylinder and see if compression increases a good bit.  Worn rings it will come up quite a bit worn tight  valve not so much.   A leak down test  could be also used to show worn rings. Some special tools required. Not what most DIY have. 
 

Burnt exhaust valve.  

My Yamaha generator was giving me fits just wouldn't start at times checked almost everything and yet?  It had a tight intake valve 15 minutes later after adjusting valves runs like new.    70 psi is very low if it were a single cylinder engine it wouldn't even start.

Once you get the bodywork off, the plugs and cam cover are pretty quick and then you get access like this. You can even see the edge of all four exhaust cam buckets. VFR owners can only dream of easy access like that...

VFR V4 and rear head so deep under there. Had 1999 Magna 750 a good bike but liked to rev higher to make power and carbs. Never got that deep just removing filter housing looked very difficult. A good engine and no vibration self balancing due to design. A nice bent set of feeler gauges will will work on SW head.
I've adjusted valves on FJR1300 and it's not easy pulling cams, it's tight. Timing chains are a pain and getting it all back in time is fun. A shim kit is is nice to have but 90% you will never need. I've sanded shims to get the proper clearance and put the rough side under the bucket worked for me.

Terry Smith wrote:

I hope the valve adjustment fixes the compression; with shim under bucket valves, the clearance closes up as the valve recedes into the head, which makes any valve noise quieter rather than louder. Eventually you get to a situation where the valves can't close and you lose compression, you also run the risk of burning a valve as it can't cool effectively.

The valves on the Swing are easy to check once the plastics (seat/footpegs/maintenance cover/engine cover) are removed, and the engine is easy to turn to the right position with the belt cover removed. Based on the design, I would not expect the clearance to change quickly as the Swing is low revving and the shim/bucket layout is usually very robust. The same layout is on my 09 ST1300 and that hasn't changed in 50,000km of running (I have checked it twice).

Sorry for the lag time in reply. Yeeeeehaw!! I've got a brand new Silverwing. You were right the valve adjustment brought the compression up and she's running like a top. In fact the shop said she hadn't had a valve job since 2010. I bought her in 2015. Like an idjit, I thought when I asked a shop to do a 'point to point' that that would include them telling me if I needed a valve adjustment. I know better now. Back to my original plan of putting at least 100k on her before looking at another bike (if Honda releases the Deauville again, that might be it) for now she's plenty fun and can't be beat for storage to and from work. Thank you all for the comments. I really appreciate it. Richard.

Thanks for the update and for closing the loop Richard. Glad to hear things are straightened out for you without major work or expense.

Ride On. Happy to hear it's all good. At 60K that's nearly 4X times the normal valve interval check and things can go wrong. I do need to inspect mine soon at 28K .