Triumphrat

quagmire

I took the bike up to our local Brit Bike Club's show sunday. What a nice ride! Yesterday I noticed that the bike was backfiring and felt sluggish. I took it out again today and the bike felt like it was running on one cylinder. All the wiring checked out this time. I took the plugs out and the left was fine, but the right looked like the one on the left:


The left still looks like this:


I dropped the needle down one notch, put a new plug in and it looks like the first picture on the right. What gives?
Also, when I took the plugs out of the cylinders immediately after I turned the bike off, the right side smoked thru the plug hole and the left didn't.


[ This message was edited by: quagmire on 2006-09-26 15:53 ]

__________________
Hey, What's this oil on the floor?

Mecchanica

The plug is oil fouled. Looks like the right side is letting oil in from either the inlet valve guide or the rings. A leakdown tester would be helpful here.
Drain the crankcase and measure the oil which runs out. If it's more than four or five ounces, then there is wetsumping occuring and you will need to pull and clean the oil pump. But.....since it's just one cylinder, more likely it's the guide or rings. Sorry about that. Try a retorque and readjust of the valves, just to eliminate a possible, if unlikely, cause.
And put the needle back in it's original position. The clean plug is good to a bit lean already.

__________________
Triumph old, Triumph new, any Triumph will do.

OzBloke

Quag,
I agree with Mechanica - the right side is an oil leak into the top of the cylinder, and left side is too lean.

I had exactly the same problem, and it was the exhaust guide. Not just worn, but the whole guide had come loose in the head.

A compression test should tell you if the rings are worn down - there would need be a significant difference in the pressures to show up so quickly as oil buring in the cylinder - ie loss of the oil rings and at least one compression ring.

Coming up to winter in the north - time to pull the head.

Pete

__________________
Per Ardua Ad Astra
(Through difficulties to the stars)

quagmire

I was afraid you guys would say that. The head was redone, all new valves and guides. The head was retorqued and the valve clearences checked When Don Hutchinson went over it a few weeks ago.

About the compression test, will my local automotive garage be able to do that? If so what kind of pressures am I looking for?

Thanks

peter

__________________
Hey, What's this oil on the floor?

johnnypence

you can pick up a compression tester for a reasonable sum (cheaper than getting someone else to get off his fat butt and do it for you) at wal-mart or pep boys. you just screw it in the spark plug hole and turn the engine over. i think your haynes manual will even tell you the compression PSI you want to see.

__________________
Sic semper tyrannis

quagmire

Johnny is this what I need:
Compression Tester

$30.00 not bad.

__________________
Hey, What's this oil on the floor?

johnnypence

unless i'm stupid or wrong, and i've been accused of both before.

__________________
Sic semper tyrannis

quagmire

Me too, but I don't think my wife counts. :-D

__________________
Hey, What's this oil on the floor?

flyrodder

I am certainly no expert on this, but I believe you are getting good advice to check the cylinder compression. After spending weeks of effort trying to track down a potential electrical problem and fiddling with the carb, I still could not get my bike to start easily or run right. I finally bought a compression tester and learned that one cylinder had zero compression. I squirted about a teaspoon of oil down the spark plug hole and retested. The compression increased to 90lbs, then dropped back down to about 10lbs. I had badly worn rings and piston in that cylinder, and also an intake valve that appeared to have been sticking. If I had not checked the compression I would probably have still been fiddling with the carb.

By the way, I got the advice to do the compression test from this forum.

Thanks to all of you for your advice on this forum!

__________________
flyrodder

jimballard

HI Quag,

Just to keep my reputation as the "village idiot" in good stead, let me ask you a very stupid question. Is your choke open all the way? Sounds silly, but one never knows. I can tell you a story about that some day.

Hope it's the choke: Jim

__________________
Jim Ballard

The older I get, the faster I was....until lately!! (Speed IS the fountain of youth)!