Bogged down in high altitude?

hotrod1 said:
I was surprised because the PO looked like he kept good care of the bike.
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Well, keeping a vehicle clean (and indoors) is no guaranty for proper service...
At least you've found the obvious cause of the trouble, get a new filter in (OEM is perfectly fine IMO) and keep your eyes open for other signs of neglect... like the brake fluid in the clutch hydraulics...
 
ST1100Y said:
Well, keeping a vehicle clean (and indoors) is no guaranty for proper service...
At least you've found the obvious cause of the trouble, get a new filter in (OEM is perfectly fine IMO) and keep your eyes open for other signs of neglect... like the brake fluid in the clutch hydraulics...
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......and anything that is 'out of sight, out of mind';). While you have that tupperware off, I would SERIOUSLY un-plug that Voltage regulator, Clean the contacts, stuff the female end with dielectic grease THEN plug back in. Do that with ALL the accesable plug-ins while the tupperware is off. It WILL save the cost of an alt., reg., or both down the road!;)
 
Installed new fuel filter, old one looked neglected as well. Started her up and went for a ride. Cold engine was still sluggish. Idle seemed improved and ran a little smoother. Seemed a little more responsive when warm, although I just took it for a short ride. My next step is to replace plugs, oil, and filter. Bought a new timing belt because this bike has been in 100+ temps for 20 years. I like the di-electrode grease idea. Thanks, Rod
 
hotrod1 said:
Cold engine was still sluggish.
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Might require a little choke on starting, now with all the fresh air coming in... :lol:

Idle seemed improved and ran a little smoother. Seemed a little more responsive when warm, although I just took it for a short ride
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Should give it the change to fully warm up (~20 min), but could still be in need of some carb sync too...
 
hotrod1 said:
Installed new fuel filter, old one looked neglected as well. Started her up and went for a ride. Cold engine was still sluggish. Idle seemed improved and ran a little smoother. Seemed a little more responsive when warm, although I just took it for a short ride. My next step is to replace plugs, oil, and filter. Bought a new timing belt because this bike has been in 100+ temps for 20 years. I like the di-electrode grease idea. Thanks, Rod
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.......Welcome,.......yeppers, way cheaper than an alt. or reg,..........and ANY aging bike NEEDS this done.......not just our STeeds;).
 
UPDATE;
Before leaving for TenSTock, new iridium plugs, oil change. Everything seemed great, after 150 miles the bike lost all power, pulled off of the freeway and she died. Started one more time......then dead. Had it towed to a dealership (scarry$$), thought I missed the STock. The mechanic had it diagnosed in 15 minutes: fuel valve/fuel filter dampner. He bi-passed the valve. Bob from Pa, at the stock says he rebuilds them. Apparently a common problem with the ST 1100.
Got back on the road, no issues and made it to and from the stock.
Should I leave it bypassed or fix the valve.............

What is your suggestion????

Thanks, Rod
 
It's up to you... the only purpose the valve serves is to not flood the carbs and possibly the cylinder in the event of a tip over. Many of the 1100 riders have theirs bypassed.
 
Just returned from Estes Park , Colorado. Bike ran great up to 12,000 feet with fuel valve bypassed. I now believe Colorado has some of the most beautiful areas in the world. Absolutely magnificent vistas, and animals. I did not want to come home. Thanks for all the input from every one. Rod
 
I was recently going through passes in WY and UT at elevations between 9500 and 10400 feet, and noticed nothing. Mine is a 96 with only 50K miles, owned since new.

Not sure if this can be it, but due to my negligence in letting bad fuel sit in carbs overwinter, the bike needed a complete carb clean this spring, an expensive fix, since I paid a Honda shop to do it. Maybe the cleaning led to my high altitude performance.
 
hotrod1 said:
The mechanic had it diagnosed in 15 minutes: fuel valve/fuel filter dampner.
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Well, John did suggest to also check the auto fuel valve/petcock...

Apparently a common problem with the ST 1100.
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I object on "common problem"... as m/any other parts on an automotive can/will the diaphragm age, dry out, get brittle... and suffer a rupture one day...
From the safety-POV this valve should be restored and put back in duty...
 
The mechanic who diagnosed the problem said some Gold Wings and GL's have the same issue, he has seen it many times. I agree about the repair, I ordered a repair kit and now its working well. The old diaphragm had a small tear on the edge. It's all back in service now and I am considering NatSTock......Rod
 
Your right, I just read the thread again. John was spot on. Since it worked going back to the valley, I did not think that was the problem.
 
Just as lights, kill, side-stand and brake-light switch is the fuel supply a safety relevant issue... one wouldn't like to have a bogging/stalling engine right during a passing manoeuvre or while trying to cross a busy intersection ;-)
I always go over all relevant parts, precautionary, complete overhaul/check-up like in aviation... in this I've small "preflights" as well as "annual majors"... a small item failing can really spoil a nice vacation/ride... and I'm not in the mood to end up stranded on some remote, abandoned alpine road... having to bear the never-ending rants of a significantly sulking TB aside... :lol:
OTOH does the ST reward already a little TLC with bomb proof reliability... I ride them rigs since '92 and they'd just never let me down...
 
I BET YOU HAVE A WEAK FUEL PUMP. I HAD THE SAME PROBLEM . I ALSO HAD A 78 GOLDWING AND RAN WEAKER AT HIGHER ALTITUDES BUT LOWERING A GEAR AND RUNNING HIGHER RPMS, IT WOULD STILL GO . I COULD NOT GET MY ST INTO ANY RPMS OVER 3000 WITH OUT IT BOGGING. I BELEIVE THAT THE HEAT FROM THE ENGINE EXPAND THE GAS CAUSING PRESSURE IN THE GAS TANK. THATS WHY THERE IS A BIG SWOOSH OF AIR WHEN THE GAS CAP COMES OFF. I THINK THE TANK PRESSURE HELPS AND MASKS A WEAK FUEL PUMP. WHEN MY ST STALLED (2X) ON A TRIP BOTH TIMES IT WAS AFTER DRIVING FROM HOT AREA TO A LOT COLDER AREA. WHEN I OPENED THE GAS CAP THERE WAS NO GAS TANK PRESSURE. WHEN THE GAS COOLS AND TANK PRESSURE IS REDUCED. BEFORE I CHANGED MY FUEL PUMP EVERY TIME I PULLED OF THE GAS LINE (HOT) TO CK FUEL PRESSUE, I HAD TO LOOSEN THE GAS CAP TO STOP FUEL FROM COMING OUT( BIKE WAS SHUT OFF). MY FUEL PRESSURE WAS LOW, HAD LESS THAN 1 PSI AND A WEAK FLOW. I HAVE DRIVEN A FEW CARBURATED BIKES IN HI ALTITUDES BUT I COULD ALWAYS GET THE RPMS UP TO RED LINE / NOT THE ST WITH THE BAD FUEL PUMP
 
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