2007 Bonneville Running Rough

[Petrinijd]

Hey gang, this is my first post on this forum so I hope I'm doing it right.
I bought this 2007 Bonneville back in January and it ran great at first. Then it started running rough so much so that it would die. After it sat for 10-15 minutes, it fired right up and I was riding for a coupe of days until the problem came up again. This began happening more frequently and now I cant even ride it around the block. Sounds like maybe its running on only one cylinder before it dies. I've changed spark plugs but that did not work. This is my first bike ever so I don't really know any of the signs that might point me to one problem or another.
Any advice that you can provide would be helpful.
Thanks
Jeff

 

[CarlS]

Jeff, welcome to TT. Check the coils; you may have a bad coil.

 

[Petrinijd]

Thank you Carl!
Can you recommend a vendor for these parts?

 

[CarlS]

I bought mine from Baxter Cycle. Baxter is not cheap but very honest, dependable and knowledgeable.https://www.baxtercycle.com/

https://www.baxtercycle.com/
Here are two more online suppliers. Both of these are owned and operated by Triumph riders and are good guys, I have done business with both of them over the years and have ridden with both of them.

https://newbonneville.com/
https://bellacorse.com/

 

[sikatri]

Also this link for Hermys Triumph eStore:

https://www.triumphestore.com/

 

[scr1200xc]

If I thought I was not firing on a cylinder, I would verify before buying parts. You can do basic tests on coils with an ohm meter, but it sound like your problem is intermittent, so it might not show up with that kind of testing. You can also get an in-line spark checker really cheap from any auto parts store and check for spark while the bike is running rough. Make sure it is actually a spark issue before you go chasing your tail on it. With a recently purchased used 2007 carbureted bike, you may just need to clean the carbs.

 

[Rocky]

If I thought I was not firing on a cylinder, I would verify before buying parts. You can do basic tests on coils with an ohm meter, but it sound like your problem is intermittent, so it might not show up with that kind of testing. You can also get an in-line spark checker really cheap from any auto parts store and check for spark while the bike is running rough. Make sure it is actually a spark issue before you go chasing your tail on it. With a recently purchased used 2007 carbureted bike, you may just need to clean the carbs.

I think that's good advice.

 

[Petrinijd]

Thank you all for the great advice. The bike only had 2,500 miles on it when I bought and had recently been in a shop for service.
Another item that might be noteworthy, I did leave the petcock open a couple of times overnight and gas went down into the cylinders. Would this trigger a carb cleaning as well?

 

[sikatri]

I’d definitely empty the fluids and change or clean the plugs at minimum.

 

[scr1200xc]

Thank you all for the great advice. The bike only had 2,500 miles on it when I bought and had recently been in a shop for service.
Another item that might be noteworthy, I did leave the petcock open a couple of times overnight and gas went down into the cylinders. Would this trigger a carb cleaning as well?

If leaving the petcock open resulted in fuel leak-through; that is a pretty strong sign that the cabs might be gummed up. Fuel will only leak through if the floats are stuck or the needles or seats are shot. Couple that with a 13 year old bike only having 2500 miles on it, making me suspect it sat a lot. Unless non-ethanol fuel was used, or the fuel system was drained when stored; there is a high likelihood that the carbs are gummed up. Don't take this as me being confident that this is where your problems lies. It is very hard to diagnose issues like this through a forum. All I can say is that I would be suspicious of carb fouling creating a fuel delivery problem. Personally, I'd check spark because it is easy to do, I'd check compression because it is also easy to check, then I'd be looking at fuel delivery (carbs).

Take this all with a grain of salt. I am not, nor have I ever been a qualified mechanic. I am just a cheap bastard who hates paying people to do things I can figure out how to do for myself, so i have spent a lot of time chasing/fixing problems with motors on bikes, boats, cars, mowers, etc...

 

[Petrinijd]

If leaving the petcock open resulted in fuel leak-through; that is a pretty strong sign that the cabs might be gummed up. Fuel will only leak through if the floats are stuck or the needles or seats are shot. Couple that with a 13 year old bike only having 2500 miles on it, making me suspect it sat a lot. Unless non-ethanol fuel was used, or the fuel system was drained when stored; there is a high likelihood that the carbs are gummed up. Don't take this as me being confident that this is where your problems lies. It is very hard to diagnose issues like this through a forum. All I can say is that I would be suspicious of carb fouling creating a fuel delivery problem. Personally, I'd check spark because it is easy to do, I'd check compression because it is also easy to check, then I'd be looking at fuel delivery (carbs).

Take this all with a grain of salt. I am not, nor have I ever been a qualified mechanic. I am just a cheap bastard who hates paying people to do things I can figure out how to do for myself, so i have spent a lot of time chasing/fixing problems with motors on bikes, boats, cars, mowers, etc...

From one cheap bastard to another, I appreciate the advice.