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Discussion Starter #1
Im new to triumphs, but have been rebuilding vespa and lambretta 2stroke engines for several years. This one has me stumped. My bike (1970 T100R)has been getting progressively harder to start over the last few weeks and has been burning a lot of oil- like a quart every 2 weeks ish - last night I changed the oil - 100ccs 20/50 in the chain case and 500ccs 80/90 hypoid gear oil in the gearbox. Then went to bed. THis morning, not only is the clutch stuck and wont disengage but I cannot get it started - it was running yesterday. Would a change in the gear oil do this? I cant even get it started with ether. I ahve good spark, plenty of gas, gas getting to the carbs...
Again, I am used to dealing with simpler engines, this is my first foray into 4T. I appreciate any information you can give, I ride the bike to work and while I can drive, its not preferable :D

thanks!
 

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Discussion Starter #3 (Edited)
Thanks for the input, unfortunately clamping the clutch lever down overnight didnt help. I also stuck 2 new plugs in and no joy. I know that it isnt uncommon for 2 separate things to happen at the same time, so Ill ask 2 different questions. Please be patient, Im not a moron when it comes to motors, I just am new to working on motorcycles and Im having trouble finding good resources for working on it. I have the Haynes manual (total crap) and the triumph workshop manual.

Anyway...

I just want to make sure that the clutch sticking isnt oil related, below is a photo of the 2 fill areas I used, the weights and measurements of oil. I totally drained both sides and refilled both locations with oil. If it matters, the gear oil I used is Kawasaki SAE 80W-90. API Service Classification: GL-5, GL-4 (HYPOID).



Are these correct?

Next, with the ignition, the battery is charged, points cleaned, new plugs, no start. Not even with ether. Is it possible that the clutch and lack of ignition are related?

Thanks in advance for any input.
 

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According to your manual the primary chaincase should get 300 cc. You have a levelling plug as well to ensure that you don't overfill. The gearbox should get 375 cc and also has a levelling plug so you don't overfill. Ensure you removed both parts of gearbox drain plug when draining.

Not sure how many miles you ride in "two weeks" but regardless, a quart of oil loss is excessive. Ensure you are not "wet sumping". Ensure oil is returning to oil tank and the oil level in tank remains constant.
When you drained the oil in the primary chaincase, only about 300 cc or less should have come out. Your clutch should not be immersed in oil as the drain levelling plug will help prevent this. Too much oil in the primary will cause the plates to stick.

Ensure carbs are cleaned especially pilot air circuit.

Clutch plates sticking is not related to engine not starting.
 

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Hi I suspect your trumpet is wet sumping ie oil is draining from the oil tank into the crank cases.. the illusion is that it is burning oil.. This causes hydronic lock and makes it difficult for the engine to start.... Two options available... 1) strip down the oil pump and replace the ball bearing and check hat the bearing seat is undamaged... Clean and replace as required 2) Purchase a oil tank tap with an inhibitor switch so you can't start the bike without the oil switched on... as regards the sticking clutch? Modem oil is not designed for the older type clutch material ... Try replacing the oil with a type suitable for older engines.... Castrol do specialist oils for the older stuff...
It's also worth noting that there is a misconception regarding valve clearance on older Triumphs that cause starting problems and running problems once hot, most manuals tell you to set the inlet valves at a tighter tolerance than the exhaust.. In fact it's the other way round as air flow cools the pushrods and rocker housing on the front of the motor and heats up the rods on the back... I have rebuilt several Triumphs including a T100ss , T120R and my personal ride a T150 which is bored out to a 1000cc and race specced.. TJ
Ps excuse typo errors as using iPhone and sausage finger.. :) Ride Safe


Sent from my iPhone using MO Free
 

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If the clutch plates refuse to release, remove and soak them in kerosene overnight.
Use a paintbrush to clean them and dry them. (dry clutch)

There appears to be a serious problem with the engine.
["has been burning a lot of oil- like a quart every 2 weeks ish".]

Lots of smoke or a leak?

I`m not familiar with 500`s, but in the second picture isn`t there a cap (filler hole) on the outer gearbox case for adjusting/connecting the clutch cable?
Seen here removed:
 

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You could put an extra 100 ml into the primary case anytime and it it would do no harm.Any excess will drain into the crankcase.I supect it would need at least 200 ml in the chaincase.20W50 oil is correct.
Don't worry too much about the sticky clutch plates.If you go for a ride,they will break free under power if you hold the clutch lever.You might only need to ride 10 or 20 feet.

I have no idea why the engine won't start.Have you got spark at the plugs?

Triumph twins don't wet-sump through drian-back through the pump.You dont need a valve on the oil hose.
 

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Discussion Starter #8
Youre right, it does only want 300ccs of gear oil. It hasnt entirely broken free, but you can tell it wants to. How did I arrive at 500ccs? I called my local Triumph guy and asked. He may have been thinking about another style of bike with a larger engine because I took the overfill plug out and about 150ccs came out.

Caulky: No. There isnt a plug hole on the side like on yours, its on the top, directly under the carb.

Triumph120V - I ride it about 150 miles a week, just to and from work. I am able to squeak away from time to time for fun so call it 175-200 miles / week. I have a leaking push rod tube that is blowing oil through the fins of my cylinder, enough so its is typically covered in oil (top of the list of things to fix when I put it up for the winter) but I dont know that it equals 1 qt every few weeks.

Re: Wet sumping - would that prevent me from even starting with Ether? I have replaced the spark plugs and still cannot start.

Back in the days before we all got married and had kids, I rode vepsas and lambrettas with a group of guys and our creedo was if you ride it, you fix it. period. Im just getting started with this motorcycle, hampered for time with a 18 month old baby and hating the fact that I dont know the answers to n00b questions like this when I can rebuild a scooter motor with my eyes closed...
 

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What do your plugs look like?
Was the bike blowing smoke when running.
A quart still sounds too excessive for a pushrod leak unless you were leaving a puddle when parked.
Check your valve clearances and that the valves are properly opening and closing.
 

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Discussion Starter #10
one of the plugs looks decent coffee with cream, the other is pretty oily. Infact, now that the bike wont start it comes out with oil on the electrode.

That same side's exhaust pipe blew a ton of smoke. I noticed it most when I was getting warmed up in the am but it may have been smoking that much all the time, its hard to tell when youre driving.

I started it up and let it idle to warm it up for the oil change, it died mid idle I changed the oil and went to bed. THat was the last time it ran, just a few days ago.

Ill check the valve clearances. I suspect this is one of the problems for sure.

Thank you all for all your help. This is a really fun bike and I just want to keep riding it!
 

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Im new to triumphs, but have been rebuilding vespa and lambretta 2stroke engines for several years. This one has me stumped. My bike (1970 T100R)has been getting progressively harder to start over the last few weeks and has been burning a lot of oil- like a quart every 2 weeks ish
I gather you just bought this bike.Were there any claims that the bike recently had head work done,including valve-guide replacement?

A bad job on guide replacement,where the head gets scored,will cause oil leakage between the head and guide.You get plenty of oil smoke,which starts about one minute after start-up.Fixable without even removing the head,if you can seal around the guides under the lowers spring collars.

Can you see air bubbles in the oil returning to the oil tank?That would normally mean no wet-sumping.Another test is to run a hose from the oil tank breather into a cup of water.The hose must blow bubbles in the water,about 200 ml of air at 3000 rpm. Do this test with the engine cold ,then hot.

If there's no guide leakage and no wet-sumping,it's time for a ring job.

Compression pressure should be around 150-180 psi on a warm engine.
 

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Discussion Starter #14
I got the bike at the beginning of the summer. because I want to do the work on it myself, I took it to a shop to have it gone over and bring it to a level, stable place so I know what it sounds like and feels like when running "right". He put in new rings, new valve guides, and 2 new valves.

So...

youre probably right. What do I use to seal the bottom of the guides?

Since I cannot get my bike to start, what is the proper cold psi reading?

Thank you everyone for your input.
 

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The damage on a valve-guide job normally happens if the old guides aren't blasted clean before they are removed.Any carbon on the guide gets dragged through the head and scores the hole.As long as the new guide is still tight in the head,you can seal it.

You can take the valve springs off without removing the head.You'd need to bolt a tube (about 3/4" diameter) across the head with 1/4" UNC bolts x 2-1/2" long,where the rockerbox bolts on.Use string on top of the piston to hold the valves up,and lever against the tube with a fork or strong open-end spanner to compress the valve springs.

Some just use a high-temp silicone sealant around the guide,after it's well cleaned with brake-cleaner etc.
Try this:
*Clean it up with brake-cleaner or even Loctite primer.
*When it dries,soak Loctite 290 around the guide.Wipe off the excess after it's had a chance to soak in.The excess will remain liquid.
*Clean up the lower spring collar and fit it back with Loctite 567 around the guide under the collar.You could use silicone sealant instead of Loctite.

You're less likely to have a bad ring job.The cylinder should have been honed with approx 180 grit hone (150-220 grit).
If it was assembled with dry rings,they should seat almost immediately.
It's better to load the engine immediately,and not let it idle or run without load for long.
It's not good to use a synthetic oil,until the rings are well-bedded.
Even a high-detergent mineral oil can cause cylinder glazing,if the engine isn't loaded enough while the rings are bedding in.It's better to alternate between high load then closed throttle,about 3 seconds each,than to run at light to medium load.Try to keep the revs about 4000 rpm.

Even a less than perfect ring job shouldn't use as much oil as you have.I'd expect at least 120 psi with the engine cold.At 100 psi,it could be difficult to even start.
 
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