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Discussion Starter #1
I was kickstarting my T 140V tonight when the kickstarter jammed after a couple of inches movement. I've taken off the outer cover and found that the kickstarter quadrant is not jammed in the kickstart pinion teeth as I thought it might be. ( I had tried putting her into gear and rocking back and forth without success ).
I tried rotating the back wheel with first gear engaged and the plugs out- it wouldn't turn.
I'm a bit stumped now- has anyone got any ideas how I can find out what's happened?
 

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Try using 2nd or 3rd gear with the rear wheel.

Does your T140V [I don't know the year of your bike] have an electric start? Sounds like something has dropped into your timing gears.

Have you tried rotating in say 3rd gear backwards?
 

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Year of manufacture???????????????????
 

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Hi Ploughboy, Does rear wheel rotate freely in neutral? It should.

What happens if you pull in clutch & free clutch? Can you break free clutch with lever pulled now by turning rear wheel hard?

If yes you can turn wheel with clutch pulled the trans is not causing no turning of motor.

If you can NOT break free clutch turning rear wheel or by temporally refitting outer cover & motor will not turn over you have to try to rotate motor by other means.

Remove spark plugs & look in plug holes with a flashlight (torch) & see if you see anything or cyl full of liquid or something odd like that.

Such as removing inspection cover if you have one on primary or remove primary cover & turn motor with wrench on crank nut. Start by turning nut clockwise as not to unscrew nut. If crank won't turn with a wrench. With spark plugs out crank should rotate fairly easily with wrench.

You may see a chain problem or something else with primary off. If crank doesn't turn that's bad. Something inside motor is stuck.

If crank turns & you see slack in chain change direction then we're looking at some odd thing going on in clutch or something.

The point here is to locate the problem area with the least amount of disassembly.
Don
 

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Discussion Starter #6
Try using 2nd or 3rd gear with the rear wheel.

Does your T140V [I don't know the year of your bike] have an electric start? Sounds like something has dropped into your timing gears.

Have you tried rotating in say 3rd gear backwards?
Hi tridentt150v- I've got some rotation at the back wheel ( forwards and backwards) now when she's in fifth gear- maybe a quarter of a rotation, then it stops. It's a '78, kickstart. The back wheel rotates freely in neutral.
 

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Discussion Starter #7
Thanks for those thoughts TR7RVMAN.
I'll work through your suggestions, but now, having replaced the outer cover I seem to have nothing happening when I pull the clutch lever. There's no resistance at all. Have I missed something obvious replacing the cover?
 

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Hi Ploughboy, I just put my '73 Tiger in 5th gear & rotated wheel. Much less than yours. I have larger rear sprocket 46t. Looking at spoke nipples, I get just over 2 nipples free rotation of rear wheel.

When you say nothing happens when you pull clutch lever, what do you mean? No resistance at all?

Is cable hooked up inside outer cover? Visible through trans filler hole. What do you see when you look through inspection cover on primary for rod adjustment. You should see pressure plate lift about .115"(at little more than 3/32").

I should have mentioned last time to check main shaft nut for tightness. A very loose nut will lock trans if main shaft moves towards left side. When trans is locked from a very loose nut it will not allow rotating rear wheel. Since you say wheel rotates the shafts are not locked by poor alignment at the moment. If you feel for it & have a skinny enough finger you can put finger through filler hole & feel a loose nut if you know what to feel for. The few loose nuts I've seen could be moved with finger easily. You can also grab adjuster nut for clutch rod very tightly with needle nose pliers & push/pull on it & see/feel the pressure plate move. If it's loose it often moves easily with the pliers. Back off rod adjustment first a few turns & lock nut before doing this test.

I'd look into why clutch lever moves oddly now.

Remember even if motor is seized solid, The clutch should free normally like it always does with clutch lever pulled.

If clutch frees as it should & motor still won't turn over when you kick it or rotate rear wheel, it's time to remove primary cover & put a wrench on alternator rotor nut & see if motor turns then.

Sounding like the motor seized or primary chain is broken & stuck or the like. Or tensioner broken & jammed up somehow.
Don
 

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Discussion Starter #9
Hi Don
I've taken off the outer cover and the primary cover now. The primary ckain and tensioner look fine and the chain rotates with the back wheel ( in fifth) as far as the wheel moves till it sticks again. I have noticed that when the left hand piston comes to the top of it's travel the inlet valve head can be seen down the spark plug (too much I think)hole and the piston seems to hit it. I have put a small piece of wire under the valve head and the piston will trap it so you can't pull it out. I've taken the tappet inspection cover off and that valve seems seated OK, so not sure what's happening?
 

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Hi Ploughboy, Hmmm.... That is interesting. I don't have the knowledge off the top of my head to say if the valve is open to far or not from the photo. I'd have to compare to my bike. I know you can see the valves pretty well when open as I've looked at them many times.

A few thoughts. When motor is stuck, put a rod, screw driver or dowel down cyl. Mark it & compare with other side to see if piston is coming up too far. Coming up too far is another subject we'll only get into if that is found.

If you've not changed valve adjustment yet, valve clearance can give some clues.

I gather from what you say the valve is still moving & not stuck fully or more open?

If.... you can get the right intake fully open what is valve clearance on left? It should be at least close to normal clearance. If clearance is very loose that can indicate a bent valve. Like .020-.030+". If clearance is zero valve may be held open some or a lot. You say it looks normal closed, but is it?

If push rod jumps out of the tappet or rocker balls & sets on edge of ball(s) it will over lift the valve & might interfere with piston. But if it's still stuck on top of ball ends the rocker/valve should look pushed down. You can look with a torch inside the rocker box & visually see top of push rods & see if they are socketed into rockers as they should be. I don't know why push rod would come out, all of a sudden during starting other than the valve stuck in it's guide, then came free & push rod is unseated somewhere.

When you back piston down slightly, can you see witness mark on piston where valve contacted it.

You could try backing off rocker adjusting screw & see if motor moves farther compared to the marks you made on test rod earlier.

BUT!!! Keep upward tension on rocker arm to keep the push rod notched in. If you let rocker get too much clearance with screw removed or backed out too far, it might let push rod jump out.

I've been crazy busy with elder care lately so I'm even more fuzzy minded that usual & my time is consumed by that. It might be a few days before I can pull my plugs & check look at my valve/piston clearance.

At this point you are into serious diagnosis. So go slow & easy. We want to find root problem & correct it or it can happen again.
Don
 

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I had to check the amount of valve movement when I recently re-built my T100R as the people that fitted the camshaft pinions (as I didn't have the tool at the time) unfortunately fitted the pinions on the wrong keyways, so I spent some time staring down the plug holes to watch the pistons hitting the valves and working out why the valve timing was way off. I had no-where near the amount of movement in your photo. Different engine, yes, but that looks to be way too much valve intrusion to me. Plus, you seem to be looking at the edge of the valve head - is the valve bent?

Equally, the valves in my TR7RV don't seem to intrude as far as shown in your photo. Does not look right to me.

As Don says, if the balls have come out of the pushrods and are locating on the sides of the cups you'll get this effect too. Something's not right.
 

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Its either a bent valve or a valve seat has come loose and is jamming the valve open = a bent valve usually :(

either way, you need to start stripping the bike and rebuilding.
 

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Discussion Starter #13
Firstly thanks to everyone for their thoughts and suggestions, BUT I have discovered the problem and I'd love to know how it happened! ( other than my incompetence.)
Yes its a pound coin!
So I recently had new valves and guides, a rebore and new pistons, so obviously I put the head back on.
And didn't notice a pound coin in there?? And then she ran really well for 500 miles or so till the kickstart jammed? There's no damage to the piston, valve barrel or head. There's no other way for anything to have got in there, is there?
Anyway, at the risk of being drummed out of the forum for making stuff up, that's what I found. Has anyone else found weird stuff in the engine?
Can the engine have run normally with that in there? I've partially reassembled it to check and the engine rotates smoothly so that picture of the valve being very visible seems normal and it's the same on the other side.
 

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Hi Ploughboy, At least the mystery is solved....

What is the white oval? Kind of looks like bottom PRT seal?? At work things falling into the motor during assembly is always a concern. Or falling into air filter housing during service & getting sucked in. If even a very small item or pebble gets stuck in valve seat the piston comes up & bends valves. Some of the Mercedes had plastic bushings break apart in intake manifold. Would smash spark plug, but 75% of time would not bend valve.

I've seen my share of small washers & nuts stuck in top of piston, but never a coin!!

My 2 year old grandson loves to hang out in the garage & "work" with Dad. He likes to "install" things in the oddest places. Have to keep an eye on him, but he loves this stuff.

Regarding bent valves, I would turn head upside down at angle & pour solvent or petrol into the combustion chamber such it fills the valve pocket. Hold head like this & look into intake port to see if liquid is leaking through. It should not leak a trace. Do same to exhaust valve. If any leaks remove valve & spin it in guide to check for obvious bend & wobbling. If ok, clean seat & recheck. If still not good, lap valves with fine compound. Look at valve & seat for non contact which will be obvious where there is no fresh lapping marks. Lap until good. Or send out for grinding.

Sometimes the piston is damaged such it pinches top ring as edge of piston is bent down. From what I see doesn't look like much piston damage. After cleaning carbon, inspect for sharp edges & burrs from the coin bouncing around. Flatten, smooth any burrs or sharp edges.

Can you post photo of head. I'd to see what coin did to head.

Are you running air filters? Could coin have falling in air filter & got sucked through carb? Coin looks to large to pass through, then by valve but I don't know.
Don
 

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must have been during assembly? Coin doesn't look small enough to fall in the sparkplug hole? maybe as Don said, through the inlet?
I can't see how your motor would run for miles with that coin in the combustion chamber, has to be a very recent addition.
 

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Discussion Starter #16
Hi Don
I checked the valve and no leaking of petrol. The picture shows a small nark near the valve head and a little carbon off the valve, no piston damage. I think you and tridentt150V are right that it can't have been in long. It must just have got in and jammed when i kickstarted her. Probably when I was adjusting the carbs. ( I'm not running air filters)
The coin is a pound coin and the silver bit is the centre of it squished out leaving that goldy ring
BTW the other picture is of the two top push rod cover tube O rings (71-1283)
One is very tatty and the other less so but not in great nick. They were new 500 miles ago- have I overtorqued or is this normal?
 

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Hi Ploughboy, You should buy a bunch of lottery tickets as a lucky man! Or... you used your luck up on the Triumph.

Anyway, I can't tell for sure, but looks like some nicks in head which will smooth out nicely. Same with piston at edge of valve relief.

Good you found the problem & now have a repair path. Glad you didn't bend valves or have major damage.

Regarding the PRT upper seals, that is not from over torque. The torque wrench sets the torque. The PRT seal crush is a product of the thickness of head gasket in relationship to if head or cyl have been skimmed & all that.

Saying that I've seen these red soft seals do that even with proper crush . I'm personally not a fan of them. I personally like the Viton O-rings which can come in any color but from Rabers were usually brown or black.

Push rod tube seal crush is a whole subject unto itself. Did you test crush at assembly? Even .015" is enough. I feel over .035 is getting to the max I like. More than .040" is not recommended & can cause head damage.

The official spec in Triumph Bulletin # 324 November 1969 is crush .030-.040".

Deburring tappet block sealing surface & head bore for PRT is essential to preventing leaks. I usually put a thin smear of silicon on the round O-rings. Still they often will start to seep after about 5 years.

If you have too much crush even with thinner white bottom seals, you might think about thicker head gasket. Solid copper .080" thick.

Regarding air filters, unless you have a specific race track reason to not use air filters, you are asking for trouble. No filters can wear slides, carb bore rapidly also. Where I live you won't cover 3k miles without wear out carbs & cyl bores.

I don't know how that coin got into your motor, but you'd not believe what can get sucked through a carb. Pebbles you'd be certain too heavy to suck in is not uncommon. Again I don't know the size of the coin compared to passing by valve, but small bits are thrown into air all the time by passing motorists. I've had them hit my legs often. A gas cap once. That hurt! I have factory air filters. Always surprises me how much little twigs, bits of grass & insects is in them besides the expected dirt.

Don
 

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....I don't know the size of the coin compared to passing by valve....
Here you go Don, 23mm dia, 2.8mm thick and dropping in value every day. Agree on the lottery ticket, I can't see how the engine ran with this in there and no damage as a result. Pleased at the outcome though.
 

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Discussion Starter #19
Thanks Don, I'm away for a couple of weeks cheering Ireland on to winning the rugby world cup so reassembly starts then. I will use the viton rings as you suggest
 
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