TR4A warmup

[ChrisR-4A]

My 4A is standard with CD175 carbs, except for an electric fan and electronic ignition. and has run fine for the last few years. However, since removing the cylinder head it has developed a warm up running problem. It starts ok with about 1 inch of choke but after 1/2 mile under load it appears to run lean if the choke is pushed in far and will not pull cleanly without some choke for about 3-4 miles. After this it runs fine, all the power and performance it always had and carries on ok all day. I have checked and ballanced the carbs, diaphrams, and recent new fuel pump.

 

It's like it's drawing air somewhere but only when cold, any ideas?

 

Chris.

[Rob Salisbury]

Hi Chris,

Well at least you know that your carbs are set fairly lean!........ What air filters are you using? my 4A is running on big K&N's,standard points and crank fan and takes a similar time to warm up (it's a pig in cold weather even with a winter thermostat)......... check the plug colour when fully warmed up...(do a proper plug chop if you really want to get it right)........ if OK leave well alone.

Cheers, Rob

[stuart]

Chris I had a similar problem with the strombergs on my 4A, it was a pig until the temperature reached nearly normal and never really cured it until i put twin 40s on. That cured it!! Bit extreme i grant you but it may be that your thermostat needs looking at to see if it is the original type with the shroud which will give quicker warm up.

 

Stuart.

 

My 4A is standard with CD175 carbs, except for an electric fan and electronic ignition. and has run fine for the last few years. However, since removing the cylinder head it has developed a warm up running problem. It starts ok with about 1 inch of choke but after 1/2 mile under load it appears to run lean if the choke is pushed in far and will not pull cleanly without some choke for about 3-4 miles. After this it runs fine, all the power and performance it always had and carries on ok all day. I have checked and ballanced the carbs, diaphrams, and recent new fuel pump.

 

It's like it's drawing air somewhere but only when cold, any ideas?

 

Chris.

[ChrisR-4A]

Chris I had a similar problem with the strombergs on my 4A, it was a pig until the temperature reached nearly normal and never really cured it until i put twin 40s on. That cured it!! Bit extreme i grant you but it may be that your thermostat needs looking at to see if it is the original type with the shroud which will give quicker warm up.

 

Stuart.

 

 

Thanks for the info guys, I Have now cured the problem and the answer came from another Forum topic.

It was the inlet/exhaust manifold nuts not being tight enough, I tightened them this evening and had the choke full off in under a mile

 

best regards Chris