Bad News for me

[mrquadriga]

It is a sad day at our house. A couple of weeks ago my '80 1100L started performing very poorly. Not being mechanically inclined I waited without riding it until I could connect with an independant shop owner and trailered my bike over to his shop. This afternoon he called to tell me the details... cylinders one and four have 120 to 130 lbs(?) compression, two and three have 20 or less. I kept oil in it, changed it every 1500 miles and didn't ride it like I stole it. Still, the motor failed. It has 22000 miles on it and the finances aren't there right now to pay a shop to fix it and frankly I'm not sure it would be worth it. I DO NOT plan on taking it to a junk yard and will be picking it up tomorrow to bring home. Would you please weigh in with what it would cost to rebuild at about 60 dollars an hour labor charge. I need this type of information to help explain everything to the finance director of my household....my wife. This will help our decision. Many thanks to all on this site....-Pete

[Matt Vann]

It could be rings or valves. It depends if it was a wet or dry compression test. If it were me, I would do as much of the work as I could myself and farm the rest out to a machine shop that knows bikes. Believe me, I've spent plenty of time in front of a similar finance comittee.

[tfb]

The fact that the compression is shot to pieces on the inner two cylinders leads me to suspect that it may be something to do with overheating (cylinders 2 and 3 always have a harder time). So along the way you will need to try and ascertain if a particular problem caused your engine to expire (and fix it before you spend good money on the rebuild), or if it was simply getting worn out with good use.

Bascially there's nothing for it but to strip it down to find out. The good thing about pulling these engines apart is
1. it's very easy;
2. it will cost you nothing.

Once you've got it apart, you'll be able to see what needs doing.

But I know you'd like an idea of what you could be up for. Well, it all depends... at the very least, you will be up for 4 sets of piston rings, honing the cylinders, head and base gaskets, valve stem seals, and 4 exhaust flange gaskets. Here in Australia that didn't leave me much change out of $800 (and that was me doing all the labour except the cylinder honing & bead-blasting of the head).

If you need new pistons and a rebore, the costs take a significant hike. If you need a new set of valve guides pressed in, up some more. Then there are the many little extras along the way that you'll inevitably need, like 'pillar nut' O-rings etc. If the valves and/or valve seats have been burnt, throw in more $ for new valves and seat re-cutting, etc.

Look, I know this is probably sounding really scary and you're starting to sink into the gloom, but just take it a step at a time. First dismantle your engine (invest in a manual if you haven't already got one, or download a freebie one that covers the 1100 TSCC engine from ManualClub.com), and figure out exactly what you may need to do. Then get back to us here and we can give you the best collective wisdom on what to do next.

And remember, if you do most of the labour yourself, you will save lots of $, too. These are good, straightforward engines to work on, so don't be afraid of working on them yourself. Take your time, with a manual on hand, and all will be well.

[Jethro]

I'm very surprised to hear the motor gave up the ghost at 22k miles. I have two 1100E's that I ride within an inch of thier life every single weekend. On the 81, I melted the exhasut cam seats and the motor still had 100 psi per cyl. Not to mention I would change the oil every 5-10k miles... the 83 gets better attention, but still sees redline quite often during a ride.

Have you kept up with valve adjustments? Can the shop tell you if it's rings or valves? Any decent shop would be able to tell you. If he can't, ask him if he did a leak down test as well as a compression test.

[ScottMc1100L]

mrquadriga, like any other terminal situation, unless you have complete faith in your primary care mechanic, I'd get a second opinion.

Does sound a little serious for the mileage IMO.

[relic-rider]

MR. Q,
If this happened all of a sudden on 2 & 3, I might suspect a blown head gasket between these two cylinders. One leaks compression into the other and vise-versa on the other stroke. Or possibly the timing chain jumped a few and maybe the valves got bent by hitting the piston? Pulling the head to check this is easy and shouldn't take long. This can be done with the engine still in the bike. To bad you aren't a little closer, as I'd check it for you for nothing.

Dan

[mrquadriga]

Gawd! This place rocks! You see, I don't even know what to ask them and you folks have helped out. Thank you Jethro, tfb, Scott and relic. Relic, I might be willing to trailer down for some straight talk. Let me ask some questions of the shop and I'll post what he told me in here with an update. I'm writing your responses down so that I don't forget.....remember, I have no skill with a wrench! I HAVE the wrenches....just don't know how to use them. Stay tuned. And thanks to all....-Pete

[nabrams]

Relic-Rider and Jethro are exactly on-the-money. It could be misadjusted valves (not enough clearance between valve and cam - leading to low compression) and/or blown head gasket - I have had both of these situations on my 1981 Honda CB750.
Now, the valve clearance issue is relatively easy to diagnose and fix yourself - see other posts.
Diagnosing the blown head gasket is fairly easy (see other posts), but replacing it is another matter entirely. The engine has to come out of the frame and the head needs to be removed. It took me at least 20 hours to do this (It would take less than 10 if I had to do it again, now that I know what I'm doing). I'm just trying to give you a realistic idea of how much time you'll need to invest.
If it is a blown head gasket, a mechanic will charge several hundred dollars to replace it (for labor - the gasket is fairly inexpensive). So it makes no sense at all to hire him to do the job - for that money you could buy an entire engine from eBay.

[quakeholio]

Rebuilding is an option, but at a grand you can start looking for other bikes as well. It's not a choice I would like to face myself, but I have done it for less.

[tfb]

relic rider, I don't see how it could be a blown head gasket between cylinders 2 and 3, because we've got a cam-chain tunnel inbetween.

nabrams, to take off the head and cylinder block, it isn't necessary to pull the engine out of the frame.

Jethro's question about the valve clearances is definitely worth following up, esp. as you only need to pop off the cam cover to check them.

[rustybronco]

Jethro's question about the valve clearances is definitely worth following up, esp. as you only need to pop off the cam cover to check them.

GETS MY VOTE! and you can be taught how to use your wrenches.

[tfb]

GETS MY VOTE! and you can be taught how to use your wrenches.

Yep -- 22 cam cover bolts (or whatever the exact no. is) is a pretty good start.:-D

[mrquadriga]

Have you kept up with valve adjustments? Can the shop tell you if it's rings or valves? Any decent shop would be able to tell you. If he can't, ask him if he did a leak down test as well as a compression test.[/QUOTE]

Alright, distance traveled from when the lack of power started until I got home was about 10 miles. It was started probably a half a dozen times after that to see if it would clear up. Would faulty valve adjustments cause irreparable damage? And no, I know nothing about the valves being adjusted in the two plus years I've owned it. (ashamedly, I don't know what a valve is but let's not get into that right now) -Pete


P.S. If anything else, this will become a tutorial for me even if I just part it out to the fine folks here....

[relic-rider]

relic rider, I don't see how it could be a blown head gasket between cylinders 2 and 3, because we've got a cam-chain tunnel inbetween.

nabrams, to take off the head and cylinder block, it isn't necessary to pull the engine out of the frame.

Jethro's question about the valve clearances is definitely worth following up, esp. as you only need to pop off the cam cover to check them.

Yah, you're right there. If it leaked between the two it would send compression into the crankcase. So, that leads to the timing chain maybe jumping one or two links causing leaky valves. Something drastic happened here and valve clearances don't change that fast unless something suddenly went bad. Maybe the cam chain tensioner broke. Like these guys said, just pulling off the cam cover will probably tell the story. It's easy.

[Jethro]

Yes, I didn't realize this happend all of a sudden.

My 81 jumped time at one point. That would be my new vote with Dan.

Regardless, it's most likely not rings or a cyl problem, unless for some miracle the pistons both burned through at once.