T140V 1976 Composite Gasket

[solomon]

Just to say, using a battery drill had good very low-speed control. You don't want an 850w power drill blasting off at uncontrollable high revs. The battery drill is light too, helping keep things under control.

If the drill revs too fast, you won't get the 45⁰ crosshatched honing.

Take it very easy. Don't dwell on a spot while rotating tool. Whole process was only a few goes up and down.

If there are any tiny 'bumps or humps' the tool will much better flatten them than sandpaper.

 

[Rudie]

Don't dwell on a spot while rotating tool.

Particularly at the top and bottom of a bore, too easy to end up with an hourglass shape bore. If you use a hone on a drill, pass it out of the bore completely at each end.

Thoroughly wash cylinders afterwards

Scrub in hot soapy water, wipe dry with clean paper towel, repeat until the paper towel is completely clean. Then do it again ...

 

[Migsan]

Particularly at the top and bottom of a bore, too easy to end up with an hourglass shape bore. If you use a hone on a drill, pass it out of the bore completely at each end.


Scrub in hot soapy water, wipe dry with clean paper towel, repeat until the paper towel is completely clean. Then do it again ...

Thanks @solomon and @Rudie
The barrels surface seems withouth imperfections I might have a go with the sand paper just to gently remove the glaze. What grit would be best for the job 150?
Cheers

 

[solomon]

I think the stones on the honing tool I used were 150.

Just a thought. If your three piston rings had lined up with gaps above each other, there's the potential for there to be less wear down the cylinder at this point. That's to say, a vertical ridge. If there is, I'm not saying there is, that might cause the rings to again settle in this formation.

Using the honing tool might remove any ever-so-slight ridge. Sandpaper won't.

The tool is £15. Your could buy a cheap electric screwdiver.

The honing tool way might sound a bit overwhelming, but was first time I'd done it. Prepare well beforehand, watch a few videos. Do one confident, even speed,pass up, and down. Stop. Look. Repeat as necessary. Won't go wrong taking it slowly.

I know Lunmad's video uses a bit of sandpaper...

 

[Migsan]

I think the stones on the honing tool I used were 150.

Just a thought. If your three piston rings had lined up with gaps above each other, there's the potential for there to be less wear down the cylinder at this point. That's to say, a vertical ridge. If there is, I'm not saying there is, that might cause the rings to again settle in this formation.

Using the honing tool might remove any ever-so-slight ridge. Sandpaper won't.

The tool is £15. Your could buy a cheap electric screwdiver.

The honing tool way might sound a bit overwhelming, but was first time I'd done it. Prepare well beforehand, watch a few videos. Do one confident, even speed,pass up, and down. Stop. Look. Repeat as necessary. Won't go wrong taking it slowly.

I know Lunmad's video uses a bit of sandpaper...

I see your point @solomon! How about the tool to open the rings? I was reading on how easy it is to warp the rings, did you placed yours by hand?

 

[solomon]

I see your point @solomon! How about the tool to open the rings? I was reading on how easy it is to warp the rings, did you placed yours by hand?

I bought these, these sizes

Could do compression rings with fingers, but the oil rings were too difficult with the spring inside.

 

[solomon]

And made a plywood platform

 

[Migsan]

And made a plywood platform

View attachment 54815

Nice platform I Had one made like on Lunmad video as well! quiet handy. Allready ordered the honing tool! What kind of oil for honing do you guys use?
Cheers

 

[solomon]

Nice platform I Had one made like on Lunmad video as well! quiet handy. Allready ordered the honing tool! What kind of oil for honing do you guys use?
Cheers

No oil!!!!!!!
It's got to cut.
And, if oily, particles of metal harder to wash away.

 

[Rudie]

tool to open the rings?

Enter "piston ring pliers" in the search of the internet browser you use.

View attachment 54814

After all this work, why not just buy two proper piston ring clamps?

 

[Migsan]

Enter "piston ring pliers" in the search of the internet browser you use.


After all this work, why not just buy two proper piston ring clamps?

Totally right Rudolf! ordered the ring pliers and the ring compressors! In regards to the ring clearences in the manual mentions to check the gaps in the lowest part of the cylinder bore. How far down in the cylinder would that be? guessing it will be the tightest part. Also the gaps they mention are .010 to .014 my pistons are +20 should I stick to these values?
Cheers

 

[Migsan]

Totally right Rudolf! ordered the ring pliers and the ring compressors! In regards to the ring clearences in the manual mentions to check the gaps in the lowest part of the cylinder bore. How far down in the cylinder would that be? guessing it will be the tightest part. Also the gaps they mention are .010 to .014 my pistons are +20 should I stick to these values?
Cheers

Hi everyone
Just want to thank everyone specially @solomon and @Rudie for all the help!
Instaled the new rings after honing and so far so good no traces of oil in the barrels. Hopefully it should be good now
Breaking the rings now riding briskly between 2000 and 4000 rpm trying to get in as many hills has I can. Couldn't get a dedicated break in oil here but found a api SG 20W50. Allready retorqued after 32 miles ride. will retorque again and change the oil + filter when I complete 500 miles. Still getting quite dark plugs though. I have stay up floats and place the edge of the float 2mm below the edge of the bowl. I read that with this type of float the hose level method should be used but I struggled with it. maybe it's I am missing something on the carb tunning. Idles nicelly at 1000 rpm.
Cheers

 

[solomon]

That's great news. Me, I wouldn't worry about the plug colour just yet. Sounds you're doing a good job of running in the rings.

You could switch to the hotter plugs I recommened. Stopped mine fouling, although I've just switched back to 'normal' and it doesn't foul anymore. Have swapped silencers in the meantime.

I've 'just' got the old style floats, original Meriden. Never measured their height, so can't be constructive there.

Anyway, great thread. Helpful.

 

[Rudie]

new rings after honing and so far so good no traces of oil in the barrels.

oil
SG 20W50.

if mineral oil.

dark plugs
stay up floats
edge of the float 2mm below the edge of the bowl.

StayUp floats, float needle on its seat in the float bowl, the top surface of the float should be parallel with and just above the float bowl gasket surface.

2mm below the edge of the bowl is for earlier hollow white floats.

read that with this type of float the hose level method should be used

Using an outside hose linked to the float bowl through the bowl drain to set the fuel level is best and should be used irrespective of float type.

struggled with it.

Much depends on the inside diameter of the hose used - the smaller the diameter, the smaller the ratio between the area of the top of the fuel and its circumference, the more the level is affected by the friction of the surface tension. Use hose with as large an inside diameter as possible, keep banging the hose with something like the handle of a screwdriver until you are as sure as you can be the fuel height indicated is correct.

hotter plugs

Using plugs with a lower heat grade than recommended to mask a rich mixture fault is "treating the symptom, not the cause" and, at worst, can hole a piston when the engine becomes hot (high ambient temperature, using engine performance, etc.).

Better is to use plugs with the correct heat range but a centre electrode type less likely to foul - Triumph originally recommended Champion N3, NGK equivalent is B8ES; however B8EV, B8EVX and B8EIX have centre electrodes made of different alloys, are less likely to foul if the fuel/air mixture is not ideal (B8EIX particularly, BR8EIX is more common but has a 5,000 Ohm resistor, not what you want unless your bike has a component with digital electronics).

Nevertheless, best is to fix the problem causing the "dark plugs".

 

[Migsan]

StayUp floats, float needle on its seat in the float bowl, the top surface of the float should be parallel with and just above the float bowl gasket surface

Done 100 miles so far. I guess it should be more than enought to burn the residual oil from the assembly.

I had the float levels parallel with top of the float bowl. Reduce it to the 2mm mark and the plugs are still fowling. couldn't see any signs of fuel starvation. New set of plugs pulls really strong but after some 20-30 miles started to fell the engine gagging slightly and becoming less responsive to the throttle.
Mixture screw is 1,5 turns out.
My commando fowls the plugs as well but doesn't affect the running at all. Made the experiment of lowering the float level to 2mm and could see major diference on the plugs. In fact to lean now.
Tomorrow I was gonna check the neddle valve seats. Before with the original floats thats how I adjusted the hight. Could it be that if the neddle valve seat is not all the way in the float level measurements aren´t acurate?
Any thoughts?
Cheers

 

[Rudie]

gonna check the neddle valve seats.
Could it be that if the neddle valve seat is not all the way in the float level measurements aren´t acurate?

If the float valve seat is "not all the way in", the float will not set correctly.

However, the important measurement is the fuel level in the bowl, you need to set the float to achieve this. Correct fuel level, the float level is wherever it is, as long as - StayUp float - the float top surface is not any higher than parallel with and just above the bowl's gasket surface.