Triumphrat

johnnypence · 03-23-2006

i am pretty new to triumphs, and to high-maintenance bikes in general, so i'm looking for some troubleshooting advice.

i paid a mechanic to help me take my 72 tr6r from neglected, rotten, jury-rigged, strip-nutted heap onto the road safely (i'm NOT the guy who hotwired the ignition and stripped all the nuts).

the mechanic did a great job, and it has so far been very fun and performed well.

but today, i was BETRAYED! i went to run an errand on it and it would NOT start and run worth a darn. i strongly suspect something in the carberuation, but i don't know how to diagnose it.

symptoms:
kickstart produces "compression coughs" just fine, but no fire unless the carb is primed-to-dripping and the throttle is open about 1/4.

then, if i goose the throttle at all (at the mechanic's advice, i now use a slow, steady throttle goose instead of the blip-blip i want to do), it quits.

also, if i DON'T goose the throttle, it quits.

after the engine quits, it then takes another hundred kicks to get the same results.

changing air/gas screw settings actually seemed to have some effect, but i have blown out my knee and i'm just too tired to mess with it anymore.

is there an issue where the cylinder heads have to be in a certain position? how would i figure that out?

does weather have anything to do with it? the mechanic removed the choke cable, saying that i'd only need it on the coldest days. last night was "cool" -- like maybe in the 30s, but now it's low 60s outside. dampness?

i'll go ice my knee and check back in a few hours.

[ This message was edited by: johnnypence on 2006-03-23 09:47 ]

hobbit · 03-23-2006

I removed the choke from mine 25 years ago, and rain, wind, shine or snow, I've never needed it.
What do the plugs look like?
Could be ***** in the carb, if you have a drain plug in the bottom of the float bowl, remove it gently & see if theres any water or debris in there . . . If there is, that's an indication of the problem.
The timing would be another thing to check, my old bsa had a habit of vibrating the backplate round regardless of how well I screwed it into place.
Whatever it is, if it's been running well up to now, I reckon it's going to be something fairly straightforward to sort.

johnnypence · 03-23-2006

plugs are brand new and getting spark -- when it does run, it runs on both cylinders. they may be gunked up if there's gunk in the fuel or getting into the carb though.

thanks. i'll poke around on that suggestion for a few minutes.

******
plugs were pretty grimy and timing did not sit right where it should according to the boyer diagram. cleaned and adjusted.

it didn't start by the third kick, so i walked away while i could still walk. will try more later.

[ This message was edited by: johnnypence on 2006-03-23 11:54 ]

hobbit · 03-23-2006

If it's been standing for a time, could've got rusty inside the tank. When I rebuilt mine I fitted inline fuel filters and gave the tank a good scrub out.

93-Daytona · 03-23-2006

Hi Jonnypence, had the very same problem myself with my '69 TR6 Tiger. Sounds very much like a ignition coil problem. With the Boyer unit fitted it's best to have two 6v coils rather than 2 of the original 12v coils. Check this first, then check to see that the linking wire from coil to coil is secure.Then see if you can loan two 6v coils in known good condition,and try them, trial by substitution can save tons of time and guesswork.The symptoms you describe is exactly what mine did. With the plugs removed and fitted to the caps and placed on the head,spark would still show at the tips when the ignition key was flicked off and on, so it took me a few hours to finally work out the problem. Just because I could see ample spark I went straight to the carb checking also the manifold, and checking the valve adjustments, especially the inlets. Everything checked out, so I next checked the ignition timing, not that the plate nor rotor can really ever come loose,but checked anyway. Then I decided to swap coils, BINGO!
Not only did the bike fire and idle perfectly, but it started 1st kick with no throttle! The exhaust note sounded crisper also.
I too saved the TR6 from a slow demise and spent NZ$8000 over a 6 year period getting it to 'original' condition, right down to new Triumph manufacture pipes and mufflers, got them as new 'old' stock. A collector now has the bike and rides it most weekends.
The important extras I added were, Boyer Unit, Spin on oil filter, Morgo Rotary Oil Pump, Hyde Mushroom Adjusters, Progressive rate fork springs, Solid State Rectifier, Oil pressure gauge mounted in another Tacho casing, 55/60 Halogen light, a FuelStar petrol canister and a Barnett clutch stacker plate. The bike covered nearly 60,000kms while I had it. In that time my only breakdown was a ripped fork Gaiter, 3 times! Ran it on Penrite HPR30 in the winter and HPR40 in the summer. Changed the oil every 5000kms. Used Auto Trans fluid in the primary,changed at 5000km also, and Penrite G/Box oil, changed every 10,000km. The bike NEVER leaked oil.
The passageways to and from the pressure release valve were bored slightly oversize to allow for the copious amounts of 'rotary' pumped oil to circulate without over pressurizing the tract to the exhaust cam followers. When 1st fitted the pump caused a leak at the base of the exhaust push rod tube, the boring cured this.I removed the head and barrels for a 'look' at 40,000km, no sign of wear at all, cams,followers,guides,pistons or rings. Cylinders were remeasured and compared to 1st assembly notes, almost no wear at all. Having consistant ignition control and heaps of quality oil being well pumped and filtered adds a huge amount of life to an engine. With the engine running at idle and the oil tank cap removed it was very satisfying to see a literal 'firehose' of oil returning to the tank. None of this bubbling,intermittent dribbling oil that the original plunger pumps produce!
Let us know how you get on. Hobbits suggestion of rust in the tank is worth looking at also just for peace of mind. The filter in the banjo of the carb is very fine and easily blocked. In line filters are a good idea also.
Cheers,Kerry

johnnypence · 03-23-2006

it does in fact have some light rust in the tank. my mechanic said i would want to take care of it 'before too long" -- i'll get in that carb over the weekend and check it out if things don't get better tomorrow.

for now, the main thing is my knee. ow.

bonnietiler · 03-23-2006

You know that when the choke lever is on..that is cable is tight, then the choke is off..it works in exactly the opposite way to how you would imagine. This is why most people remove the airslides in the choke mech, and just use the carb 'ticklers'

OzBloke · 03-23-2006

Just another possible avenue to follow.....

Make sure there are no air leaks betwen the carb(s) and the intake manifold/head. Loose bolts, cracked balance pipes, broken seals/gaskets, etc, can cause similar symptoms - especially given your comment about the air screw having some positive effect.

Couldn't hoit to check....

Pete

KADUTZ · 03-23-2006

Has any one checked battery voltage under a load Boyers wont function properly without sufficent voltage.
How old is the battery,what size is it ,when was the bike last run?
Carbs dont go bad sitting over night or for a few days a battery can

texspeed · 03-23-2006

Try taking out the air screws and spraying carb cleaner in the orifices. Then re-install the screws till gently seated and turn them out about two turns. Remove the bowl drains and see what comes out, also remove the lines from the petcocks and turn them on to see what type of flow you have. Are there any fuel filters on the bike? The logical thing would be to know what your dealing with first....fixing one thing downstream may work for awhile, but whats upstream needs to be known. Clean tank, clean filter/screen, good needle and seat and functioning float, clean jets/passages, good intake manifold seal, adjustments correct.....and so on. That it ran good and now it's not means carbs/fuel system in my book. If you have a short screwdriver you may be able to remove the bowls and check float function and also you can spray carb cleaner into the jets and passages.....I've found that the air screw trick above works alot of times though...helps that it's easy to do. :-D

[ This message was edited by: texspeed on 2006-03-23 19:58 ]