Riding on one cylinder***UPDATED With Pics***
 

...sucks a$$.

Was cruising along at 60 MPH on the '87 FLHTC when Ifelt the engineintermittently lose power. I pulled over and noticed theengine would not idle, and vibrated much more than normal.Checked all the usual stuff, and then decided to try and ride out the last 5 miles home. I noticed a considerable loss of power, and the engine had to be revved so it wouldn't stall at red lights.

First thing I did whenI got home was pull the plugs. The rearplug looked good, but the front plug was wet and had some carbon deposits on it. With the plugs out, I cranked the engine with my fingers over the plug holes. The compression in the rear cylinder blew my finger right off the hole, but I was easily able to keep my finger on the front hole. I pulled the front rocker cover and cranked the engine. Both rocker arms seemed to move as they should, with no excessive play in the pushrods.

The top end was done at a New England Harley dealer 8,000 miles ago when a rocker arm broke and stranded the original owner. The guy ended up going for new pistons, Andrews cam, etc. I can't imagine what went wrong, but I'll know in a few days when I pull the head.

RE: Riding on one cylinder...
 

Stuck valve maybe?

RE: Riding on one cylinder...
 

if you have lots of carbon no the front sounds like you migh thave a bit stuck under avalve. Thing to look at is why is the front jug building up carbon when the back isnt. I wonder if you have a broken ring or the jug wasnt honed corectly for the new psiton, 8 k miles aint much really

RE: Riding on one cylinder...
 

I say you should at least pump some air in the cylinder to see if it is a valve stuck open or a broken ring.with that much fuel washing through the cylinder it could be the rings have lost their seal.you just might have had a fouled plug to start with.Good Luck!

RE: Riding on one cylinder...***UPDATED***
 

Looks like a broken exhaust valve. Lots of carbon on the piston, too. The previous owner had the top end done around 8,000 miles ago. Can't understand what went wrong, since I ride conservatively. When I purchased the bike, it had straight pipes. I put a set of SE's on it (the quiet ones) about 1,000 miles ago.

Here's what's in it as per the invoice:

Andrews EV27
KB9.5:1 pistons

Any insight would be appreciated.

http://www.asqtec.com/valves.jpg

http://www.asqtec.com/piston.jpg

RE: Riding on one cylinder...***UPDATED***
 

You are lucky that you don't have a hole in your piston.

RE: Riding on one cylinder...***UPDATED***
 

89 FXRS

You're right.

Since I don't know what caused this to happen after only 8k miles, I am probably going to rebuild the entire top end anyway. I might even go completely stock, so the HP will be more suited to the stopping power.

RE: Riding on one cylinder...***UPDATED***
 

A valve can stick in the guide or the guide can drop out of the head. In your case, I'm going to bet that the front exaust valve stuck in the guide. Why? Dunno. Too close tolerance when they put it together? Not factory parts? Just one of those things? Hard to say.

Going back to stock is always best for reliabiltiy in my opinion. While people who want to build up killer motors can certainly do whatever they want, they can't biatch when the blow up. I've known people with shovelheads that would smoke jap bikes all day long, but I personally think that if you want to go really fast, buy a 'busa and be done with it (after they scrape what's left of you off the interstate). I keep my bikes (and other vehicles) at a "well tuned" but basically stock level, after having gone hot rod in the past.

RE: Riding on one cylinder...***UPDATED***
 

I'm with you Hess for the same reasons. I used to be into hot VW's that would smoke V8's off the line. My 72 Superbug had 150RWHP out of crankcases that were designed for 60HP. I had to rebuild that motor every 12 months or you could guarantee I would put a pushrod throught the side of the case. All my vehicles get left pretty much stock so as to ease the pain in my hip pocket.

WRT the pictures, could detonation have caused the exhaust valve to break off? I ask this because there doesn't seem to be any errosiveblowby evidence past the exhaust valve on the valve seat. FatGuy, did you notice any engine knocking type sounds under load or when in too low revs?

Cheers.

RE: Riding on one cylinder...***UPDATED***
 

gigiflip.....I tend to agree. In addition, I want to spend more time riding than fixing. Guess I'm getting old.

I haven't pulled the valves out of the head yet. I am seeing quite a bit ofplay at the connecting rod/crank journalwhen I move the pistons left to right. I don't mean side-to-side play; it's more like the connecting rod bearings are quite worn. At top dead center, I can measure 1/4 inch of play when I move the pistons from side-to-side. There is also noticeable play at the wrist pin when Itwist the piston. It's not much, but I believe it should be tighter.Theengine did ping when I got on it, but never under normal riding.

I spoke with Chicago Harley today. I can get the polished aluminum crate engine for $2650.00 plus shipping (about $150). I'll sleep on it, then probably order the new engineMonday and be done with it. Should have it in 2-4 weeks. A stock carb and a new ignition system should leave me in good shape.

I'm looking forward to going stock.