Several years ago, I received a message from Les Mercer, who lives in England, describing a serious problem with his ST1100. He had done a thorough investigation, but wasn't having any luck determining the source of the problem.
He wrote,
"I have now got a problem that has dumbfounded the mechanics at my three local Honda dealers, so I wondered whether you were up for a challenge!
I stopped riding the bike just before Christmas. At the time it was running fine. I put it away in the garage and left the battery on trickle feed to top up what the alarm takes out. About 6 weeks later I tried to start it, pressed the starter button, got a momentary attempt to start the engine then the dashboard lights dimmed and nothing. I took the battery off and recharged it, put it back on and got the same result. I tried with another known good battery, same result. I tried jump starting from my car but same result.
I took the solenoid connector block and solenoid off, and throughly cleaned all the contacts and then checked it. It certainly gave a loud click when the button was pressed, and the resistance across the in/out terminals to the starter went to zero. So that looked OK.
I took the starter out of the engine, connected an earth lead between engine casing and starter motor case, pressed the starter button and it worked perfectly. I checked the mating faces where the motor bolts to the engine casing and they were clean and so giving a good earth, which I also checked with a multirange meter. I refitted the starter motor, pressed the button - same result.
I switched off, put the bike in 5th gear and rocked the bike to and fro in case the starter clutch had jammed. But I could not turn the engine at all. I then started worrying that, even though I had proper strength antifreeze in the coolant system, maybe the head or block had cracked and a cylinder had filled with coolant.
So I took all four spark plugs out to check. There was no sign of liquid in any cylinder. I tried the starter again, now that it did not have to overcome compression. Still the same result. I sprayed a small amount of WD40 into each cylinder and left it for an hour and then tried again - same result.
So again I put it in 5th gear and tried rocking the bike but it would not budge. I then got two friends to push whilst I sat on it and tried to bump start in 5th gear, but with the plugs out, in the hope this would spin the motor over. Instead it just locked the back wheel. The engine seems to be seized solid!
I took the inspection cover off the timing case and used a torque wrench on the crankshaft nut up to the maximum 64Nm for the bolt, and still the crank would not turn.
So there you have it - the engine is either seized or jammed with no obvious reason for either to have happened.
Any ideas that you may have will be very gratefully received."
I gave Les some suggestions of things to look for, (bent valve, broken timing belt, etc.) but none of them seemed to be likely solutions. He informed me that the bike could be shifted into neutral and the rear wheel would move, so the problem wasn't in the transmission. Hmmmm. Then, three days letter I received a happy message from Les with the subject line,"Seized ST1100 problem SOLVED!"
Hi guys,
"I contacted a guy called Ray Hinds in Reading, UK, who buys a lot of ex-police and military Pans and BMWs, refurbishes them and sells them. He replaced the severely rusted swing arm on my Pan just after I bought it (I didn't find the website warning about that until too late!). He obviously has had a lot of experience with old Pans. When I phoned him, I only got as far as saying that I had garaged the bike for 6 weeks and now it would not start and he immediately butted in to tell me the problem and the cause.
He said "I bet the bike has done between 50-60,000 miles" (it has done 59,000). "and that it appears seized".
He has come across this problem many times and on occasions the bike had only been parked for a week or two.
At that mileage, the alternator rotor is prone to seize in the stator. This can be an expensive repair because you have to take the motor out of the frame to replace the alternator. And good second hand alternators are rarely found at breakers or on eBay (although coincidentally there is one on eBay today.) A new alternator is over £400 for an ST1100 and about £800 for ST1300.
He suggested warming the alternator with a hot air gun and then a good dose of WD40 through the air vents and then rock the bike to and fro in top gear. I did this for about 30 minutes, and it freed off. I could spin the motor over on the starter with the plugs out. But I drained the battery doing so and so have put it on charge and hopefully tomorrow I will have a running Pan.
So now we are all a bit wiser. Thank you to those who have kindly made suggestions, and for those who have their excellent websites, perhaps you might like to add this nugget of knowledge to the site."
Likewise, thanks to Ray Hinds and Les Mercer for this bit of wisdom. Obviously, Les's bike has the 40-amp alternator, since there are no vents in the 28-amp model.
One point, though. The alternator can, indeed, be removed from the ST1100 without removing the engine, as documented in the 40 Amp. Alternator Installation article on this website.
Last updated on January 28, 2014 © 2010-2014 M. E. Martin, All rights reserved