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Discussion Starter #1
Hi All,

New member but I've already picked up a lot of useful information, so thanks!

I've got a 1979 T140D and it seems to be getting harder to start from cold. Once it's up and running, it fine all day, but it's getting really frustrating.

It's all standard, air filters are fine, running N5 plugs, super unleaded, and nothing obvious wrong.

Any ideas - anything to stop a grown man crying!!

Cheers
 

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Take a look at the linkage between the carbs that lifts the cold start plungers, it is sloppy at the best of times, maybe when you push the lever down on the LH carb the plunger on the RH carb isnt lifting properly?

Generally I will press the lever down first thing so that rich mixture is drawn into the engine when it gets turned over during the clutch free-ing process.

Petrol and spark plugs are the same as I use on my T140E.
 

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Besides the fiddly choke linkage, the rubber seats on the choke plungers can wear out resulting in always too rich condition.

Both of my Ds like choke full on, start engine, then choke 1/2 way off almost immediately, then choke off before riding away (less than a minute).
 

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Discussion Starter #5
Thanks for the quick responses!

I've had the chokes converted to a lever on the bars, as I was struggling to balance the bike, hold the choke on and kick the bike!

So, I'm "confident" that its operating on both carbs.

Do the rubber seats on the choke plungers come as an Amal spare? I'm about to order a couple of MK2 gasket kits, as part of the on-going efforts to cure this problem, or do they come in the kit?

When it finally decides to start, I back the lever half off almost immediately, and it runs fine after a couple of minutes warming up. It's then fine for the rest of the day.

I'm starting to think it's personal!
 

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Zimmo,

The plungers do not come with the gasket set. And they're kind of pricey for what they are. If you have the carbs off to do the rebuild, check the plungers first before you order new ones.

Also, how old is your battery?
 

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What ignition system you using? Original Lucas Rita?

Things to check:

Tappet/valve clearances.
Coils and high tension leads.
Ignition timing.
Ignition transducer/reluctor.
Ignition switch.
Battery.

All these things can have an affect on starting. Battery, tappets, and switch are probably the ones I'd look at first.
 

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It has been my experience, and I cant find the logic for it, BUT... On all my bikes it pays to turn on the petrol tap(s) a minute or so before trying to start a bike. This is not just time enough for it to fill the float chambers... On my older bikes I always flooded the carb using the ticklers which worked fine). It also works for my 1985 BMW. Which is a pig to start (for first start of the day) unless I give the fuel a minute or two. Effectively I can turn on fuel, put my gear on and wait, or wait whilst the starter motor is running, takes the same time.. Seems to be if you cant flood it, and are just using some kind of choke mechanism you need to wait.
 

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some bikes don't like the cold?

you stand in the cold with no coat and see how motivated you are.

the colder the gas the harder it is to ignite
 

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Discussion Starter #10
Well, I've worked my way through various different suggestions, but still today, about 20 kicks from cold!

As far as I understand, the Lucas Rita ignition needs the engine to be turning at 200RPM in order to start the bike. I'm guessing that cold, thick oil makes this a possible reason.

Does anyone know if the Boyer or Pazon systems work any differently, or maybe just better?

As you can imagine, it really is becoming a pain in the neck, especially as after even a 3 or 4 mile run, it then starts first kick.

HELP!!
 

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Here's the drill I use on my 78, same carbs. Switch on, choke lever down, throttle closed. One gentle prime kick. One hard kick or two. Usually starts. If after a couple of kicks it doesn't, its probably flooded. Then its choke lever up, throttle about half way open and it usually starts in a kick or two.
 

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not sure if you mentioned how your plugs look. if it is the enrichment plungers not seating well, I would expect a little soot on your plugs. I have a 79, and it was indeed the plungers causing the problem. They were about $35 each from Mitch Klempf. One thing I noticed when I pulled them out was that the little nipple on the ends was bent over, probably contributing quite a bit to the poor seating/leakage.

meanwhile, turns out I didn't need the new Tri Spark ignition I bought (for the same problem)...so let me know if you go that route, I'll take 20% off whatever they are going for these days (the Classic Twin).

John
 

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'79 Bonnie Special

Wondering how you made out. I also have a '79 T140D and had some starting issues at first as the battery was marginal. I put in a new battery and now it is a real gem. I would keep the Rita system as long as it works and I'm very glad to have it.

My bike had not been running in months due to winter and a new Buell, so yesterday I warmed up the battery, checked the fluids, tires, etc. I turned on the petcocks and let her set a few minutes to fill the bowls, flicked on both enrichers, and she started on the second kick and idled! After 20-30 seconds I usually switch off the right side enricher and gently ride away to let her warm up. After a few km, I flick off the left enricher. The linkage for the enrichers was removed years ago as it caused more trouble (for this bike anyway) that it cured.

I really enjoy my Bonnie.
 
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