Triumphrat

fcousin · 10-22-2009, 07:29 PM

HI.
I am new at this. I just purchased a 1970 Tiger. The engine was fully rebuilt and a new carburetor installed.
I managed to start the bike when I first got it with a lot of effort and numerous kicks (and tickler use). Since then, no luck!

I have changed the spark plugs (the ones on the bike were rusted and looked old). That didn't help.
When I kick start the bike, it seems like the bike starts but then dies within a couple of revs.
I looked at the plugs but they are neither black or wet.
It really looks like not enough gas is reaching the cylinders but really I am not sure.
I looked at the carburetor (Amal 930) and the choke was removed.

The one time I started the bike, it sounded great and was idling nicely (do not know what rpm though).

Any recommendations? Where should I look?
Thanks for the help.
Fred

SlowPocono · 10-23-2009, 08:42 AM

I'm far from expert on repairing these bikes but I know a thing or two about basics and overlooking simple things.

It sounds like your observation about not getting enough gas may be right on target.

Is there fuel in the tank?

Are the fuel taps open?

Is the tank cap vent plugged?

Verify the fuel flow to the carb to make certain that isn't the problem.

Maybe you are being too timid with the use of the tickler.

What are you doing with the throttle while trying to start?
Nothing is probably best but some setups start best with a slight throttle opening.

Someone else will probably give you the right answer but checking these things will be a good foundation for more involved troubleshooting.

GrandPaulZ · 10-23-2009, 10:41 AM

I agree, sounds like the fuel taps are plugged or restricted.

adam13 · 01-07-2010, 12:13 AM

I have the same problem with my 650 especially with the cold weather we are having. The guy I got it from would use a hair drier to warm the heads. I am not real crazy about doing that. I have found that using the tickler between "hits" helps quite a bit. I havent had any time to check anything else though.

jimmy bush · 01-07-2010, 10:21 AM

I've got a '68' T120 that I put new Amal 930's on. I had to go through my new carbs and clean them out. Seems they aren't too concerned at the factory about castings and flashing being left in the carbs. The old carbs didn't have the air valves (choke) but I had to install them to get the new carbs to work. Even using the ticklers, it will not start or run in cold weather unless I close the air valves. Once started, I have to drive it with the air valves closed until the carburetors are warmed up. Without them it pops and sputters. As it warms, I can reduce the amount of air valve used but it is tricky and changes with different temp or humidity so I usually just run them closed until everything gets warm. I tried different carb adjustments. I had it where it would run and idle when cool but when it warmed up it wouldn't run right. As set now, once everything is warm, it idles smoothly, responds well to throttle and runs clean.

GrandPaulZ · 01-07-2010, 01:35 PM

As mild of temps as we get in Laredo winters, I still find the best success with the air valve / enrichers in place for cool-weather fast starting. Tickling is a MUST.

68TR6R · 01-08-2010, 10:53 AM

I ride in 15F weather and do not have a choke. With a good tickle (

) it will generally start first or second kick. The trick is keeping it running. What I do is get it started and keep the rpm's up around 2200 with my left hand while running the tickler with my right to keep it running. When it starts it will idle even without running the tickler, but if you even breath on the throttle it will flame out. Do not just let it idle cold!

Plewsy · 01-08-2010, 03:27 PM

Hi all

In really cold weather the Air is very dense and is capable of burning more fuel,
so for me when the cold effects the starting I lift the needles a notch,
it makes a world of difference and can soon be changed back when the weather improves.
We had a -20 over here, so my bikes is tucked up for now as there is at least a foot of snow against my door!!
ps I am at sea level

jimmy bush · 01-08-2010, 03:30 PM

68tr6; my old carbs would start and run without the chokes. I changed them because the bores were worn out. With the new carbs, the bike will not start in cold weather unless I use the air valves and forget about idle without them. When I ordered my new carbs, I told them what bike they were for and was told they would be jetted correctly for it. They came with different main jets than the originals but run clean. fcousin said he had a "new" carb installed so maybe it is a "new carb" requirement to run the air valves when cold.

68TR6R · 01-08-2010, 09:33 PM

Quote:

Originally Posted by jimmy bush

68tr6; my old carbs would start and run without the chokes. I changed them because the bores were worn out. With the new carbs, the bike will not start in cold weather unless I use the air valves and forget about idle without them. When I ordered my new carbs, I told them what bike they were for and was told they would be jetted correctly for it. They came with different main jets than the originals but run clean. fcousin said he had a "new" carb installed so maybe it is a "new carb" requirement to run the air valves when cold.

Hey Jimmy,
My Amal 930 is also new (less than two years old). I wasn't very happy with the casting because there was a lot of burs and flashing left over, and required major clean up work. There were shavings in the pilot circuit and the pilot passages in the float bowl were much too small. Once all that was sorted I installed it on the bike, and continued to tune it up. I was able to get the top end and needle set. I had to change the slide to a 2.5 from the 3 that came with the new carb. Even though the rest of the ranges were tuned, I could never get the idle set right. I was always playing around with it. My old carb still had pilot jets instead of the bush, and I figured that was the issue. Instead of just removing the bush and installing a blanking screw, I drilled and tapped the passage just as if you were going to install another pilot air screw, and installed a spare air screw that I had. Now, I can keep the air screw at around 1.5 turns (where supposedly it is most efficient) and actually manually needle the amount of fuel at idle. Worked fantastic and I finally was able to get the correct idle.