93 Trident T300 750

[Gaffer]

Hi Folks

Looking for some help please, recently bought 93 Trident 750, I was told bike had been in storage for over 10 years. Started and ran very well but having decided to replace fluids etc, I discovered fuel contamination in sump, I checked operation of vacuum petcock which seemed to be fine, following oil drain and refill with flushing oil I carried out a cold compression test which resulted in 125-125-140 psi, whilst cranking third cylinder a 'plinking' sound was heard so test was halted. Plugs replaced (iridium) once clean, however engine will not restart apart from some loud backfiring, all plugs sparking but plug 3 was fouled badly just from short flush run to warm oil up. Could this strange noise have been a sign of valve damage I wonder and why will it not even run now considering what little work was carried out? Any ideas/suggestions gladly received.

 

[Rocky]

It sounds like dirty carbs to me, but that's only a wild guess - even though the engine ran originally.
10 years is a long time to be sitting.
I doubt that it's valve damage, but anything is possible I suppose.

 

[Gaffer]

It sounds like dirty carbs to me, but that's only a wild guess - even though the engine ran originally.
10 years is a long time to be sitting.
I doubt that it's valve damage, but anything is possible I suppose.

Thanks Rocky, was hoping to avoid stripping carbs as its a bit out of my comfort zone, hopefully someone at my local owners club might be willing to help me out.

 

[triumph david]

I am late to this post, sounds like the carbs are gummed up, i would check that first.

 

[Gaffer]

I am late to this post, sounds like the carbs are gummed up, i would check that first.

Thanks David, trying to get away with a deep soak using sea foam, I've heard mixed reports on it, but failing that, strip down it is.

 

[shanered6]

i used the carb cleaner and filled the carbs to the brim on my super 3 and it did a great job !.... although i did end up stripping them but that was for another reason .

 

[Gaffer]

Cheers Bud
Nice to know I'm in with a chance, just waiting for new air filter then I'll stick them back on and try for a burn, keep you all posted

 

[dearborn]

Licensed Master Motorcycle Mechanic here, 40+ years experience. Generally, air bleeds on carbs are what get gummed up first after sitting for long periods from fuel evaporation, though fuel passages suffer, too. Everyone tries the lazy way; spraying some stuff into the carbs, but it's a waste of time. Only sure way to clean them is to strip them, clean them and replace o-rings, gaskets. etc. Fail to do it right the first time, and you'll be getting a lot of practice taking them off and on and playing around with them and spending a lot of time in the garage, (shed). Pay close attention to condition of floats and I'd bet that the fuel tap needs rebuilding/replacing. It would be a good idea to remove the cover to see if the cam chain and valves are operating properly, have no damage, and are still properly timed, too. Just be sure to turn the engine over by hand, not by using the starter motor. If #3 plug was fouled by fuel=carb/ignition fault. If #3 fouled by oil= valve stem oil seal, valve guide, head gasket, cyl. head damage, oil return in head blocked/restricted.
After your "carburectomy", check spark, check ignition timing if you get it started. Plug wires suffer from age, too.
When diagnosing always start simple, eliminate the simplest things first. My guess is the carbs need cleaning and you may have a valve stem oil seal that has hardened and failed with age/sitting. Fuel tap should be rebuilt/replaced. And THOROUGHLY clean the fuel tank too or you'll keep filling up the carbs with crud. You can buy a cheap ultrasound cleaner for $50 or so from the Chinese tool store that will do a great job, but will only do 1 carb (dismantled) at a time. Spraying carb cleaner and poking with wires does a crappy job, so don't bother. You can do this; be methodical, follow the service manual, triple check your work, buy whatever tools you need to do the job correctly. You'll be fine

 

[Gaffer]

Licensed Master Motorcycle Mechanic here, 40+ years experience. Generally, air bleeds on carbs are what get gummed up first after sitting for long periods from fuel evaporation, though fuel passages suffer, too. Everyone tries the lazy way; spraying some stuff into the carbs, but it's a waste of time. Only sure way to clean them is to strip them, clean them and replace o-rings, gaskets. etc. Fail to do it right the first time, and you'll be getting a lot of practice taking them off and on and playing around with them and spending a lot of time in the garage, (shed). Pay close attention to condition of floats and I'd bet that the fuel tap needs rebuilding/replacing. It would be a good idea to remove the cover to see if the cam chain and valves are operating properly, have no damage, and are still properly timed, too. Just be sure to turn the engine over by hand, not by using the starter motor. If #3 plug was fouled by fuel=carb/ignition fault. If #3 fouled by oil= valve stem oil seal, valve guide, head gasket, cyl. head damage, oil return in head blocked/restricted.
After your "carburectomy", check spark, check ignition timing if you get it started. Plug wires suffer from age, too.
When diagnosing always start simple, eliminate the simplest things first. My guess is the carbs need cleaning and you may have a valve stem oil seal that has hardened and failed with age/sitting. Fuel tap should be rebuilt/replaced. And THOROUGHLY clean the fuel tank too or you'll keep filling up the carbs with crud. You can buy a cheap ultrasound cleaner for $50 or so from the Chinese tool store that will do a great job, but will only do 1 carb (dismantled) at a time. Spraying carb cleaner and poking with wires does a crappy job, so don't bother. You can do this; be methodical, follow the service manual, triple check your work, buy whatever tools you need to do the job correctly. You'll be fine

Thanks I appreciate the response, slowly finding my way around this problem.

 

[triumph david]

Rob, how are you coming with those carbs? Got her running yet?

 

[Gaffer]

Rob, how are you coming with those carbs? Got her running yet?

Thanks Dave

Sorry forgot to update thread, I ended up biting the bullet and had the carbs sonic cleaned, new plugs fitted and now running like a dream, thanks to all members for your input, no doubt I'll have need of your help again in the future, Cheers

 

[triumph david]

Rob,just about every time a engine is sat up for a long time the carb is the first thing to require complete rebuild especially with ethanol fuel. Keep the shinny side up, and send some pictures.