[TR] TR3A running poorly when outside temp goes up

[Kinderlehrer]

Yes, I suspected vapor lock. I did clean the filter and change the element,
it's one of those glass tube things- maybe I should change it. I didn't
remove the sediment bowl  -I will do that though I don't know why that would
be heat related. I have replaced the soft lines after the fuel pump. No
after market mods to the top half of the engine, but I can pull the valve
cover to see if anything looks strange. 

It seemed too lean because when I pushed the pin  or lifted the damper, it
would stumble and stall. Also, on compression while driving - going down
hills, downshifting for stops - there was a lot of popping, which seemed to
be alleviated this morning while it was running well.

I appreciate the ideas, thanks!
Bob 

-----Original Message-----
From: Randall [mailto:TR3driver at ca.rr.com] 
Sent: Saturday, August 17, 2013 4:08 PM
To: kinderlehrer at comcast.net; 'Triumphs'
Subject: RE: [TR] TR3A running poorly when outside temp goes up

> If I backed off the gas for a few seconds then gave it gas, it would 
> run
ok for a few seconds and then start backfiring again.

That sure sounds like a fuel delivery problem, though I can't explain why it
would only happen when it's hot.  Did you try changing the (aftermarket)
filter?  Check the sediment bowl & screen?  How's the tank vent?  Have the
soft fuel lines near the carbs been changed in the past 10 years or so?

> I pulled the plugs and the last 2 were black and oily.

The oily part sounds suspicious.  Do you have any modifications that would
increase oil on top of the cylinder head?  Might be worth pulling the rocker
cover, just to check that the pushrod tubes (which double as oil drains) are
open.

> I then adjusted the carbs as it seems they were running too lean.

Can you expand a bit on that?  Why did it seem too lean?

-- Randall