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

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Riding on one cylinder***UPDATED With Pics*** - 4/20/2008 3:29:53 PM

FatGuyOnABike

Posts: 10
Joined: 10/16/2007
Status: offline

...sucks a$$.

Was cruising along at 60 MPH on the '87 FLHTC when I felt the engine intermittently lose power. I pulled over and noticed the engine 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 when I got home was pull the plugs. The rear plug 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.

< Message edited by FatGuyOnABike -- 4/21/2008 5:03:07 PM >

_____________________________

2004 BMW R1150R
1987 H-D FLHTC
1986 MG 1000 SPII

Post #: 1

RE: Riding on one cylinder... - 4/20/2008 3:46:34 PM

Y2K

Posts: 715
Joined: 6/11/2005
From: SW WA.
Status: offline

Stuck valve maybe?

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Electraglide Roadtripper

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RE: Riding on one cylinder... - 4/21/2008 12:47:44 AM

Ribcracker

Posts: 298
Joined: 2/13/2008
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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

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S.T.D.E

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RE: Riding on one cylinder... - 4/21/2008 3:55:41 AM

dog155

Posts: 4656
Joined: 11/5/2006
From: Windham,Maine--God's Country
Status: offline

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!

(in reply to Ribcracker)

Post #: 4

RE: Riding on one cylinder...***UPDATED*** - 4/21/2008 5:02:14 PM

FatGuyOnABike

Posts: 10
Joined: 10/16/2007
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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
KB 9.5:1 pistons

Any insight would be appreciated.

< Message edited by FatGuyOnABike -- 4/22/2008 4:04:01 AM >

_____________________________

2004 BMW R1150R
1987 H-D FLHTC
1986 MG 1000 SPII

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Post #: 5

RE: Riding on one cylinder...***UPDATED*** - 4/22/2008 7:34:04 PM

89 FXRS

Posts: 161
Joined: 12/8/2007
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You are lucky that you don't have a hole in your piston.

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RE: Riding on one cylinder...***UPDATED*** - 4/23/2008 7:35:11 AM

FatGuyOnABike

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Joined: 10/16/2007
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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.

_____________________________

2004 BMW R1150R
1987 H-D FLHTC
1986 MG 1000 SPII

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RE: Riding on one cylinder...***UPDATED*** - 4/23/2008 7:05:32 PM

Dr.Hess

Posts: 594
Joined: 8/15/2007
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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.

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Dr.Hess
1986 FLHT: S&S carb, Andrews EV1
1987 XLH Hugger (Wife's): MegaSquirt Fuel Injection
http://www.drhess.net

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RE: Riding on one cylinder...***UPDATED*** - 4/27/2008 4:42:29 PM

gigiflip

Posts: 48
Joined: 11/5/2006
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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 errosive blowby 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.

(in reply to Dr.Hess)

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RE: Riding on one cylinder...***UPDATED*** - 4/27/2008 5:33:42 PM

FatGuyOnABike

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Joined: 10/16/2007
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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 of play at the connecting rod/crank journal when 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 I twist the piston. It's not much, but I believe it should be tighter. The engine 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 engine Monday 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.

_____________________________

2004 BMW R1150R
1987 H-D FLHTC
1986 MG 1000 SPII

(in reply to gigiflip)

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RE: Riding on one cylinder...***UPDATED*** - 4/28/2008 7:18:43 AM

Dr.Hess

Posts: 594
Joined: 8/15/2007
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Fatguy, if I was to propose a mechanism for your failure, I'd say that the motor was running too rich, built up all that carbon on the piston, which increased compression, leading to the pre-ignition. That's just a theory. The too much play in the bottom end is bad too. For $2650, I don't see how you can go wrong. I'd guess that rebuilding what you have would cost close to that these days.

_____________________________

Dr.Hess
1986 FLHT: S&S carb, Andrews EV1
1987 XLH Hugger (Wife's): MegaSquirt Fuel Injection
http://www.drhess.net

(in reply to FatGuyOnABike)

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RE: Riding on one cylinder...***UPDATED*** - 4/28/2008 10:26:44 AM

BB Sue

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Joined: 1/15/2008
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I thought the same... when I looked at getting the motor in mine pulled apart, checked, and all the worn stuff in her redone, the crate motor seemed like a better alternative for the same bucks, plus you have a known quantity to deal with, where the bike (which I got 3rd hand) was a total unknown - whether it was babied or beat. Now I can break it in the way I want, and know it'll give me a few miles...

Sus

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RE: Riding on one cylinder...***UPDATED*** - 4/28/2008 2:38:42 PM

daven9113

Posts: 91
Joined: 8/28/2007
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Fatguyonabike,

Look into the engine remanufacturing from H-D. Gets the engine back to stock. I don't know the details and cost comparison to buying new and putting it in yourself. Just another option if it was mine.
dave

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RE: Riding on one cylinder...***UPDATED*** - 4/29/2008 4:02:07 AM

FatGuyOnABike

Posts: 10
Joined: 10/16/2007
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I was standing next to the manager of a local Harley dealer yesterday when he called HD to ask if the crate motor would fit my chassis. After being on hold for nearly 45 minutes, we got the answer. As per HD, the crate motor will not fit in my 1987 FLHTC, as they say it will only fit '92 -99's (except Dyna's). In addition, they will not perform the remanufactured engine swap. I will be confirming this at another HD dealer later this week. I know there are other motors and options out there, but I'm not putting $6000 plus in a 20 year old bike that's worth $4500. Hot rodding is out of the question. I already own two bikes that will smoke most hot rodded HD's any day of the week. And, they can actually stop safely!

As it stands, I will have the heads done to stock specs, put it back together, then ride it until it blows up. Maybe I'll sell it. I have my eye on an '03 FLHTP with only 3000 miles on it.

_____________________________

2004 BMW R1150R
1987 H-D FLHTC
1986 MG 1000 SPII

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RE: Riding on one cylinder...***UPDATED*** - 5/5/2008 10:33:38 AM

Slowride262

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Joined: 7/30/2007
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Looks like a cracked piston to me.

(in reply to FatGuyOnABike)

Post #: 15