Triumph Rat Motorcycle Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
I’m new to motorcycles, but I’ve always wanted a triumph. Just picked up a non running 2003 bonneville t100for $400 from my neighbor. The guy couldn’t get it to start. I couldn’t get it start and upon further inspection I believe the right side piston has broken. It’s further down in the chamber than the left side piston and the bike will not start.
My question is do I keep it and if so how much would something like this cost? Or I have the option to give the bike back with a refund. The rest of the bike is pristine and I really like it but just don’t want to be in over my head. I’m a newbie so any help is appreciated, thanks!
 

·
Registered
Joined
·
290 Posts
The bike is already broken so you don't really have to worry about screwing it up, right? If you are not mechanically inclined or if you simply don't have a place to do it this type of endeavor may not be for you but if you want to learn buy a shop manual and get busy.
 

·
Registered
Joined
·
1,647 Posts
Sounds like the motor is toast. On the bright side the rest of it has to be worth the $400.00. This might not be the one you want to start your career of rebuilding motors with but it is fairly easy to swap out the motor for a used one. They go for around $1000.00 or a little less, you need one from a 2001-2004 790cc Bonneville or Bonneville T100. The motors went to 865cc shortly after your's was made, they fit but your carbs are set up for 790cc and it will be one less thing for a self confessed newbie to worry about. Scrambler, America and Speedmaster motors have a different firing order and your electronics are not compatible. All Thruxtons are 865cc. Don't worry if the replacement motor has plain case covers, your chrome ones will fit.
Don't know how close to you these guys are but this gives you some idea of costs.
 

·
Registered
Joined
·
116 Posts
You may want to explain more about your conclusion. It does not sound correct.

Does engine turn over on starter? Do both piston go up and down?

If it does not turn over on starter, will it turn when pushed in a high gear with both plugs out.?
 

·
Registered
Joined
·
6 Posts
Discussion Starter #5
The bike is already broken so you don't really have to worry about screwing it up, right? If you are not mechanically inclined or if you simply don't have a place to do it this type of endeavor may not be for you but if you want to learn buy a shop manual and get busy.
I’m decent when it comes to wrenching, I’ve restored a couple old cars I’ve just never messed with motorcycles before. I love the bike but not sure if I’m going to pursue fixing it. I might just engine swap it if I can.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #6
You may want to explain more about your conclusion. It does not sound correct.

Does engine turn over on starter? Do both piston go up and down?

If it does not turn over on starter, will it turn when pushed in a high gear with both plugs out.?
The engine does not start or turn over. I put a brand new battery in it. And I checked the position of the pistons via the spark plug holes. The left side piston is higher up than the right side. The right side spark plug was almost smashed from when the piston came off the arm. If my research is correct this are parallel piston bikes so shouldn’t the pistons be in the same position on both sides?
 

·
Registered
Joined
·
6 Posts
Discussion Starter #7
Sounds like the motor is toast. On the bright side the rest of it has to be worth the $400.00. This might not be the one you want to start your career of rebuilding motors with but it is fairly easy to swap out the motor for a used one. They go for around $1000.00 or a little less, you need one from a 2001-2004 790cc Bonneville or Bonneville T100. The motors went to 865cc shortly after your's was made, they fit but your carbs are set up for 790cc and it will be one less thing for a self confessed newbie to worry about. Scrambler, America and Speedmaster motors have a different firing order and your electronics are not compatible. All Thruxtons are 865cc. Don't worry if the replacement motor has plain case covers, your chrome ones will fit.
Don't know how close to you these guys are but this gives you some idea of costs.
Thank you so much man, yeah I’m going to give these guys a call. I’m not in any rush to get the bike done, when I got it I was hoping it was something simple like a new battery or plugs. The bikes got 30,000 miles on it so I’m wondering what else is going to need to be changed.
 

·
Registered
Joined
·
1,647 Posts
These bikes are pretty reliable, this one seems to be an exception. I'd check out service items like tyres and the chain and sprockets and try to find out a little more about when the motor quit. Did your neighbour own it at the time or buy it like it? One thing I'd do if I was doing work on my motor is install a TTP Safe Start. Google it. The earlier motors sometimes had an issue when starting in that the motor might kick back and it breaks the boss casting that the starter bolts to, end result need a new engine case. Later motors were strengthened but if I was going to the trouble you are I'd install one. It's one of those things that if you have it you will never know if it's saved you, but for peace of mind I'd fit one. Good luck with it.
 

·
Registered
Joined
·
1,411 Posts
I see no reason not to use a later 865 carbed engine. They will work fine with easy needle change to Thruxton needle change and main jet change if you modify the air intake or exhaust. I'm pretty sure people have converted 790's to 904's and used those carbs. Save the broken motor for parts. The cams are suppose to be better than later ones if you want to hot rod later on.
 

·
Registered
Joined
·
10,401 Posts
At 30,000 miles, there shouldn't be much wrong with it if it was maintained properly, which is an open question at this point. Weak areas, other than the usual expendables, are the ignition switch, regulator-rectifier, ignition coil, crank position sensor, and occasionally the ignitor. Foot pegs and rear wheel spokes have been known to break.

Selling just a few parts will net more than $400. You should be able to get $300 for the fuel tank alone, the carbs should be worth a decent amount too, if clean, and then there are the external bits that people break when they drop the bike, like the control levers. The speedometer and tachometer are probably worth $100 each. And so on. I'm not suggesting doing this, just saying that it's an option if you want to go to the trouble to do it.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #11
At 30,000 miles, there shouldn't be much wrong with it if it was maintained properly, which is an open question at this point. Weak areas, other than the usual expendables, are the ignition switch, regulator-rectifier, ignition coil, crank position sensor, and occasionally the ignitor. Foot pegs and rear wheel spokes have been known to break.

Selling just a few parts will net more than $400. You should be able to get $300 for the fuel tank alone, the carbs should be worth a decent amount too, if clean, and then there are the external bits that people break when they drop the bike, like the control levers. The speedometer and tachometer are probably worth $100 each. And so on. I'm not suggesting doing this, just saying that it's an option if you want to go to the trouble to do it.
The seller bought the triumph along with a Harley, and new Silverado 1500 from an estate sale for $10,000. Nothing came with service records unfortunately so really hard to tell. Everything else seems pristine on the bike except for a few scratches but that’s to be expected
 
1 - 12 of 12 Posts
Top