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2K views 11 replies 8 participants last post by  DriftlessRider 
#1 ·
Hi all,
I am new to this forum and to Triumphs in general. I recently purchased a 2008 Bonneville t100. Yesterday I noticed the oil light in the dash flashing, so I checked the oil and topped it off. I was planning on taking it to a shop on Monday when I have a day off.
This morning riding to work the light came on while on the highway doing 80 in 5th gear. I then lost all rpms and speed. I still had electrical power (lights etc) but the engine died. When I tried starting it up it cranked but wouldn’t ignite and had to be towed home. What do you think the issue is?

A friend of mine with much more Moto-experience than me Said to pull the plug and check for metal shavings as this would indicate a blown engine. I will do this when I get home from work.

Also, fyi, there was no visible oil leaking on the engine.
 
#5 ·
You're in the right place now.

Your oil light went on at 80mph and the engine shut down. That' not good and there's little you can do if you don't know what you're doing.

You can pull the plugs and see if there's metal on them, but if the bottom end failed you won't see metal on the plugs.

You can drain the oil and see what that and the oil filter look like, but you don't know what to look for or what you're looking at.

You need to get your bike to a competent mechanic and have it checked out.
 
#6 ·
When engines "blow" there is usually a catastrophic mechanical failure that will show itself.

When you tried to start the bike again, did it sound any different than before this happened? The fact that the starter can still turn the rotating assembly is a good sign that things "might" not be that bad.

Steven is right though, you will need to (or pay someone to) investigate to see what damage has occured. Pull the spark plugs and shine a flashlight down the hole. It should be brown/slightly black and the plugs have to be intact. If not, then bad.

Jack the bike up. Pull the plugs (or leave them pulled). Put the bike in fifth gear and rotate the rear wheel by hand. If you hear odd noises (other than air whooshing out of the spark plug tubes), then bad.

Ideally, you do need to drop the oil pan and inspect for debris.

You should do all of these things before trying to start the bike again, unless you are set on getting a new motor and don't care about this one.
 
#7 ·
I would just like to add to the excellent advice here, these bikes have plastic gears driving the oil pump, and they have a habit of splitting in half. They are under the clutch cover.

Having said that, the oil light stays on when oil pressure is lost. It doesn't flash, unless the pressure was coming and going at the time.
 
#8 ·
From what you described it sounds like exactly what Mr. Ripper stated. Failed oil pump gear. You may be ok. These are incredibly robust engines. Hopefully it got shut down before too much damage. I would put the side cover and inspect the oil pump gear. For reference, the failures occur from overheating and that is usually when someone lets the bike sit on the side stand and idle for extended periods of time.
Good luck. Hope the best for you.
 
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#9 ·
Yes, don't start it, check the oil pump gear, which is not too hard to find. That's an easy (relatively) place to start, and might well be the problem. You might be lucky and have caught this before it did serious damage.

If the clutch cover has not been previously removed (or possibly if it has), you'll need to order a new gasket for it. Watch out for the notorious wavy washer (search on this forum for it).
 
#10 ·
Thank you all so much for the excellent advice. I’m going to check out what I can tomorrow. I have an oil pan and magnet so I will drain that and check the spark plugs and the gears. I’ll be taking it to a mechanic on Monday as well. Again, thanks for the help!
 
#11 ·
The oil pressure light on any vehicle with an engine is on between 0 and say 7-10 psi. Off at higher pressures.
When the light comes on when driving, you must shut off the engine as soon as possible and coast to a stop before the engine seizes up.
On the bonnie it could be an oil pump gear failure, as they are nylon.
Most likely the pistons seized. Once you get the low oil pressure fixed, check the engine compression and see if it runs.
The pistons/ barrells may have become distorted after a seizure and may tend to seize again in the future. Keep your hand close to the clutch lever if you intend to keep riding it.
 
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