Need Help. What would you do? Surging and power loss

ScottyG

Joined
May 13, 2020
Messages
53
Age
67
Location
Centennial, CO
I recently purchased a 2002 ST1100 as a result of many of the fine comments on this board. I bought it with 36,000 miles on it and have put 3,000 of my own miles on it. I LOVE IT. I bought it for $2,500. The fun for value component is off the charts. HOWEVER, recently it starting developing a problem where the the bike surges forward without me turning the throttle and then sometimes it seems to have a drop of power like I'm riding a 350 cc bike. The hard part is I love to ride but have absolutely no experience with troubleshooting and even some of the most basics of maintenance discussed on this forum......so off I go to a Honda dealership hoping they can get to the bottom of it at a reasonable cost. As a start they check the plugs and coil and recommend replacement of the spark plugs and ensure that spark plug caps are rethreaded strongly to the coil wiring? They take for a test ride and feel everything is okay. When I pick up the bike and go for a ride the problem is still there. I call them and they say they will have to step by step go through the bike until the problem is solved. Makes complete sense....but given their labor rates, etc. , I could easily paying way more for trying to get this bike to work than what I originally paid for it. So I try to be smart and find one of the best independent shops around with more reasonable labor rates to give me a second opinion. He is Honda certified and seemed very, very, knowledgeable. He goes for a test ride and says he feels that the bike is dropping and running on 2 cylinder's and is very sure it is something in the electrical system. However he checks the coil resistance, spark plugs, and wiring harness, etc.......everything seems okay. After more head scratching, etc. he decides to look into the fuel system. Ultimately, he puts in Seafoam wondering if the gas in that tank is bad, etc. Take's it for a test ride and feel's it much improved. I pick up the bike, run another tank of gas through it and problem is way worse than before. Feeling brave after spending hours on this forum. I take off the plastic and look to do the fuel value vacuum by pass only to find out the that has already been done. It continues to run but it is super rough. If feels to me that it is a fuel delivery problem to the carburetors, but I'm TOO much of a rookie to attempt anything with them myself. In fact I'm amazed when some of say just pull off this and inspect and check this....I have no idea.

I interested in your comments and thoughts so I could a least talk the lingo with a mechanic to get to the bottom of this. Or did I make a rookie mistake in buying a 20 year bike when I don't have repair skills and perhaps I should trade in on something newer. I don't want to give up since so many times I have read on this forum of people who say they ridden 30,000 miles and all I have done is change fluids, tires, etc.

What to do?
Scott
 
Welcome to the forum from Cornwall UK! I would check the fuel filter and fuel pump to ensure that fuel is flowing properly and then check out the air filters to make sure they are not blocked. It may also pay to check the cap is venting properly as if air can't get in, fuel can't get out of the tank.
 
I'm living proof you don't have to be a master mechanic to fix many bike problems.
You're here, and that's a start. (Welcome, by the way!)
Do you own any tools at all?
Or are you near another member?
I know @KLRST is out your way, because he's always posting those gorgeous Rocky Mountain pics.
 
@ScottyG , the gas cap has a valve system that allows air to get in or out of the gas tank. When that vent in the gas cap fails, your bike is lacking power, because a vacuum is created in the gas tank. When the vacuum gets too strong, it could blown a sip of air inside, so the gas flow gets back to normal. Maybe this is what is causing the surge in power.

I would suggest a very simple test to see if this is your issue or at least to eliminate that possibility :
- Open your gas cap, close it, go for a ride.
Your pressure in the gas tank should then be normal, and the bike should run great.
After a while, as gas will get lower in that tank, a vacuum will develop, and in this case (when the vent in the gas cap is not working as it should in allowing new air to enter the gas tank) your fuel pump has to work harder, and you could feel you are lacking power.
Just stop, re-open your gas cap, close it, and see if it runs better.

Aaah, Yes... you need your key to open the gas cap door. You could use the 2nd key, if you have it, so you can leave the engine runnig while you re-open that gas tank.
 
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Hi Scott,

Let's just for the sake of argument assume it is a fuel related issue. What I would I check and in order of difficulty.
  • Fuel cap as Christian noted, but you can just leave the cap loose and ride around to know if that's an issue.
  • Air filter clogged - should be easy to check and not likely the cause, but who knows.
  • Bad gas - if there's any chance you got a bad tank, you can get a siphon tube from the auto parts store to empty and refill. Some guys swear by Seafoam and other additives, but I don't believe they do much. Just my opinion.
  • Fuel filter - could be clogged and not flowing fuel. Not terribly expensive, and easy to change.
  • Fuel cutoff - noted as removed already.
  • Fuel pump - should be a date on the top to indicate how old it is. There are some simple tests you can do to check the amount of fuel it's flowing. If your riding has been on hot days with a fairly low amount of fuel in the tank, the pumps do get sensitive to heat as they age. Not sure how to test other than maybe out of the tank with a heat gun to warm the motor? Mine heated up and died temporarily on a trip last month, so I'm familiar with that problem. $500ish, so you'd want to know for sure rather than guessing. Potentially there is someone nearby would could let you try using his spare pump. You could also use a remote bottle on a gravity feed if you can replicate some of the problems while sitting still.
  • Carbs - clogged jets from sitting normally impact the ability to idle as opposed to high speeds, but things don't run well. Torn membranes in the carb symptoms are documented on this forum and would seem more likely than plugged jets if the bike has been getting used and the fuel filter has been doing its job.
That's my initial thoughts. Oh, and welcome to the forum. There is more than enough knowledge here to get you up and running, step by step. I'd skip the dealer for now, this bike really isn't that complicated to work on. They really are nice bikes, so no it wasn't a bad idea to buy one, you just need to realize it's not new and will need some love.
 
ChriSTian_64 said:
Don't listen to our fellow UK members if they ask you to bring a torch near the open gas tank, to have a look inside.
By that, they simply mean a flashlight, not a flamming torch.
Click to expand...

Somebody called ?


Two questions @ScottyG :

Does the surging happen if you keep the revs high when riding. - ie ride in a lower gear ?

Do you have the pair of switches below the left hand fairing pocket for ABS and TCS ?
 
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Scott,
We were all where you are at some point in our lives, by that I mean fledgling mechanics. This stuff is not hard, and we will help you through the trouble shooting and tell you what to do to make your bike what it once was. As @Sadlsor said, there are ST owners out your way who will likely help you do some wrenching on your bike. In fact, you are only 12 hours away from @Igofar, and were I in your shoes, I would seriously consider loading my bike on a trailer and driving it to his shop through some of the most beautiful scenery in our country. You will get a lot of suggestions here, but remember, we are diagnosing your symptoms from afar, and some will be off the mark, and some will be right on. If you really don't want to do the work your self (and there is no reason not to), get a copy of the Service Manual for your bike and take it and suggestions from the guys here to your mechanic. I found a local mechanic to work on a thorny problem on my ST, I gave him the manual, he later told me he read it the night before doing the work, and his pricing was reasonable and his work excellent. He was an experienced Goldwing and Harley guy, so my ST was his first.
 
SMSW said:
Scott,
We were all where you are at some point in our lives, by that I mean fledgling mechanics. This stuff is not hard, and we will help you through the trouble shooting and tell you what to do to make your bike what it once was. As @Sadlsor said, there are ST owners out your way who will likely help you do some wrenching on your bike. In fact, you are only 12 hours away from @Igofar, and were I in your shoes, I would seriously consider loading my bike on a trailer and driving it to his shop through some of the most beautiful scenery in our country.
Click to expand...
Absolutely this! Larry will sort it out so that you will have the best-running ST that it can be.
He is about three times as far from me as he is from you, and I STILL plan to ride out there -- some day. But sooner than later.
Just don't tell @Igofar, because I want it to be a surprise!
(And, yeah - I'm kidding. I'll give him at least a 2-hour notice before showing up at his garage.)
 
ScottyG said:
HOWEVER, recently it starting developing a problem where the the bike surges forward without me turning the throttle and then sometimes it seems to have a drop of power like I'm riding a 350 cc bike.

He goes for a test ride and says he feels that the bike is dropping and running on 2 cylinder's and is very sure it is something in the electrical system. However he checks the coil resistance, spark plugs, and wiring harness, etc.......everything seems okay.
Click to expand...
Welcome Scott,

The two quotes above would seem to be related, and logical because each coil fires two cylinders, so its consistent with what it would feel like if one coil was intermittently bad. Checking the coil resistance is OK for a quick static check, but can't rule out a heat/RPM/load related misfire, so it doesn't prove the coils are both good. Unfortunately, about the only way for a backyard mechanic to confirm anything with the coils is to replace them (or one at a time) with known good units. Its also possible that the coils are OK, but there's something going on in the power connections and/or trigger signal to one or both coils.

All the other suggestions so far are very good as well, I just wouldn't rule out the coils completely just yet based on the simple static resistance test that was made.

One final question that I don't think has been asked, can you get the problem to occur just by revving the bike in the garage, or does it only happen when under load on the road? If you can get it to occur while stationary, a shop with an ignition scope could give you conclusive results on whether or not your coils are intermittently misfiring.
 
Bikeric said:
Welcome to the forum from Cornwall UK! I would check the fuel filter and fuel pump to ensure that fuel is flowing properly and then check out the air filters to make sure they are not blocked. It may also pay to check the cap is venting properly as if air can't get in, fuel can't get out of the tank.
Click to expand...
Thanks from the UK! Wouldn't that be great!....the fuel cap is not venting. I think I do that!
 
Sadlsor said:
I'm living proof you don't have to be a master mechanic to fix many bike problems.
You're here, and that's a start. (Welcome, by the way!)
Do you own any tools at all?
Or are you near another member?
I know @KLRST is out your way, because he's always posting those gorgeous Rocky Mountain pics.
Click to expand...
Fortunately, I have tools and am pretty handy. I have socket sets, spanner wenches, etc., etc., I just take off the plastic and look and say HOLY CRAP there a ton of wires, hoses, values....on and on.
 
Uncle Phil said:
My next suspect would be failing fuel pump or a torn diaphragm in the carbs.
I would be surprised if it is electrical unless you've got a spark plug wire loose on one end or the other.
Click to expand...
I sure hope the guy who thought it was fuel would check something like that. Even I can say well the fuel "pump" probably pumps fuel from the tank to the engine. However, I wouldn't know how to check it.
 
ChriSTian_64 said:
@ScottyG , the gas cap has a valve system that allows air to get in or out of the gas tank. When that vent in the gas cap fails, your bike is lacking power, because a vacuum is created in the gas tank. When the vacuum gets too strong, it could blown a sip of air inside, so the gas flow gets back to normal. Maybe this is what is causing the surge in power.

I would suggest a very simple test to see if this is your issue or at least to eliminate that possibility :
- Open your gas cap, close it, go for a ride.
Your pressure in the gas tank should then be normal, and the bike should run great.
After a while, as gas will get lower in that tank, a vacuum will develop, and in this case (when the vent in the gas cap is not working as it should in allowing new air to enter the gas tank) your fuel pump has to work harder, and you could feel you are lacking power.
Just stop, re-open your gas cap, close it, and see if it runs better.

Aaah, Yes... you need your key to open the gas cap door. You could use the 2nd key, if you have it, so you can leave the engine runnig while you re-open that gas tank.
Click to expand...

THANKS! THANKS! I did have a earlier incident right after I bought the bike. It was pretty hot here in Denver and I was looking over the bike after a ride. I opened the tank and it was low and looked like the gas was bubbling or boiling. THIS CAN"T BE GOOD! So I left cap off until everything cooled down and went to the forum and read some of the posts on the vented. So I worked with it and it seem to be venting okay and I haven't seen it again.
 
@ScottyG , I'm 57, bought my ST11 last year, that is my first road bike ever. My previous bike was a honda mini trail, CT70, 40 and some years ago.

I never done any vehicule mechanic before. I got tools, I'm taking my time. Lots of info and support on this site. Some youtube videos are also interesting to watch to learn some basic motorcycle maintenance, like replacing coolant, bleeding brakes, clutch, etc.
There is a lot of things that we can do ourselves.

As for the numerous fairing parts, they are easy to remove, but then you end up with plenty of fairing parts around you and plenty of fasteners that you probably don't remember where they go.

So, one method that I learned is to use plastic sandwich bags to put the fasteners in, one bag by fairing parts. You can identify the bags with a piece of tape on the bag, with the name of the fairing part on it. Sometimes, just 2 or 3 fasteners by bag. That 's OK. The important, is just to know with witch part they go.
The owner's manual gives the name of all fairing parts (and number of fastener I think).
Then, there are also a maintenance manuals for the ST1100 that you can get (from clymer) or even, the honda maintenance manual for the ST1100.

Honda also make another very interesting (and underestimated) motorcycle maintenance book for guys like you and me : apprentice mechanics : it is called the "common service manual".
They will explain, lets say for bearings, what are the different bearing types, how they works, where they wear, how to inspect them, what to look for, even how to remove and put the new ones, where to be carefull, etc.
In comparison, the others maintenance manual will only tell you to check a bearing and replace it if needed. That's it. Thats enough for an experimented mechanics, but for begginers it doesn't explain much.

There is a learning curve. But you have to start somewhere. The ST1100 is not too complicated, as a bike, to maintain.

Chris.
 
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Smudgemo said:
Hi Scott,

Let's just for the sake of argument assume it is a fuel related issue. What I would I check and in order of difficulty.
  • Fuel cap as Christian noted, but you can just leave the cap loose and ride around to know if that's an issue.
  • Air filter clogged - should be easy to check and not likely the cause, but who knows.
  • Bad gas - if there's any chance you got a bad tank, you can get a siphon tube from the auto parts store to empty and refill. Some guys swear by Seafoam and other additives, but I don't believe they do much. Just my opinion.
  • Fuel filter - could be clogged and not flowing fuel. Not terribly expensive, and easy to change.
  • Fuel cutoff - noted as removed already.
  • Fuel pump - should be a date on the top to indicate how old it is. There are some simple tests you can do to check the amount of fuel it's flowing. If your riding has been on hot days with a fairly low amount of fuel in the tank, the pumps do get sensitive to heat as they age. Not sure how to test other than maybe out of the tank with a heat gun to warm the motor? Mine heated up and died temporarily on a trip last month, so I'm familiar with that problem. $500ish, so you'd want to know for sure rather than guessing. Potentially there is someone nearby would could let you try using his spare pump. You could also use a remote bottle on a gravity feed if you can replicate some of the problems while sitting still.
  • Carbs - clogged jets from sitting normally impact the ability to idle as opposed to high speeds, but things don't run well. Torn membranes in the carb symptoms are documented on this forum and would seem more likely than plugged jets if the bike has been getting used and the fuel filter has been doing its job.
That's my initial thoughts. Oh, and welcome to the forum. There is more than enough knowledge here to get you up and running, step by step. I'd skip the dealer for now, this bike really isn't that complicated to work on. They really are nice bikes, so no it wasn't a bad idea to buy one, you just need to realize it's not new and will need some love.
Click to expand...
Thanks for all the encouragement. I was getting pretty down seeing the prime riding season in Colorado speed by. Maybe with some knowledge and experience it would seem like it "isn't that complicated to work on" but I feel like I'm looking a jet engine and everything got to work together.
 
ChriSTian_64 said:
@ScottyG , I'm 57, bought my ST11 last year, that is my first road bike ever. My previous bike was a honda mini trail, CT70, 40 and some years ago.
I never done any vehicule mechanic before. I got tools, I'm taking my time. Lots of info and support on this site. So youtube videos are also interesting to watch to learn some basic motorcycle maintenance, like replacing coolant, bleeding brakes, clutch, etc.
There is a lot of things that we can do ourselves.
As for the numerous fairing parts, theyvare easy to remive, but then you end up with plenty of fairing parts around you and plenty of fasteners that you probably don't remember where they go.
So, the best, you can use plastic sandwich bags to put the fasteners, one bag by fairing parts. You can identify the bags with a piece of tape on the bag, with the name of the fairing part on it, or just tape the bag on the back of the fairing part.
The owner's manual gives the name of all fairing parts (and number of fastener I think).
There is a learning curve. But you have to start somewhere. The ST1100 is not too complicated, as a bike, to maintain.
Chris.
Click to expand...
That's encouraged, I am 64 and bought a brand new Honda 650 Nighthawk. But because it was brand new I never had to "work" on it.....troubleshoot, figure stuff out., etc
 
jfheath said:
Somebody called ?


Two questions @ScottyG :

Does the surging happen if you keep the revs high when riding. - ie ride in a lower gear ?

Do you have the pair of switches below the left hand fairing pocket for ABS and TCS ?
Click to expand...

Today, it was doing it a lot in lower gears. I could be at 2500 to 3000 rpm in 1st gear and kind of being a dog and then I feel like the gas or another cylinder fires and it surges forward. HOWEVER, I've seen it happen at higher speeds as well. I was coming back from AZ in Feb going about 70mph and then it felt like it would drop out a little and start to hesitate or slow little, then I would downshift and then have to work a little to get the RPMS and speed back up.

Yes, under the left fairing pocket I have two switches "TCS control On/Off" and another that says TCS/ABS Warning Light
 
SMSW said:
Scott,
We were all where you are at some point in our lives, by that I mean fledgling mechanics. This stuff is not hard, and we will help you through the trouble shooting and tell you what to do to make your bike what it once was. As @Sadlsor said, there are ST owners out your way who will likely help you do some wrenching on your bike. In fact, you are only 12 hours away from @Igofar, and were I in your shoes, I would seriously consider loading my bike on a trailer and driving it to his shop through some of the most beautiful scenery in our country. You will get a lot of suggestions here, but remember, we are diagnosing your symptoms from afar, and some will be off the mark, and some will be right on. If you really don't want to do the work your self (and there is no reason not to), get a copy of the Service Manual for your bike and take it and suggestions from the guys here to your mechanic. I found a local mechanic to work on a thorny problem on my ST, I gave him the manual, he later told me he read it the night before doing the work, and his pricing was reasonable and his work excellent. He was an experienced Goldwing and Harley guy, so my ST was his first.
Click to expand...
I may have to do that. I have a buddy who has a trailer. I retired and would drive a long way just watch a guy work on these bikes. I could pass the wrenches and LEARN.
My Dad was great with everything around the house and taught be a lot about fixing stuff and tools....but if ever there was a car problem it went to an auto shop. I amazing when someone says...my alternator went out and replaced in a parking lot.
 
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