The Triumph Dolomite Club - Discussion Forum

I am having a slight problem with the running of my 1850 Auto, she starts fine and runs well untill hot, the tick over is not great untill I pull the choke out a bit.

I have looked at the diaphrams and they seem ok but I bought some new ones, they appear to be slightly thicker and not as flexible, I haven't had the engine running yet but I wonder if the old ones may have caused a problem or whether the new diaphrams will.

any suggestions welcome

Malcolm

Berg 'phrams tend to perish and develop pin holes and leak, so the piston doesnt rise as it should.

If your pistons are rising together as you rev the engine I suspect all is well.

If you are unlucky enough to have the earlier bergs with the stupid plastic bimetal strip down the side it may be worth looking at how they seal.

You can get new O rings for those. Later bergs from about 10000 on dont have them.

If they persist in being troublesome, a TR7 manifold and HS6's is the way to go.

Jonners

Thanks for your advice Jon, I did check for the bi-metal things and my bergs don't have them. I did find that the thin rubber gaskets had started to perish between the carbs and the manifold, so i replaced them.

I also found the water bypass gallery under inlet valves 3 & 4 blocked, so this was cleaned out before re-fitting the inlet manifold.

i did remove the manifold as I had a siezed temp sensor to sort out, this is now out but the replacement sender unit makes the gauge read too high.

Malcolm

Malcolm try a temp sender from Robsport?

GTS290N wrote:Malcolm try a temp sender from Robsport?

Thanks for the suggestion. I did indeed buy from robsport, the items came the next day.
The resistance of the RBros Temp sender unit was 700 ohms and Rob sport was about 330 ohms. I rigged up a temp gauge and a bench power supply set at 10.5 V DC and a bowl of off-the-boil-water.

The Rob sport set the temp gauge in the middle and the R Bros one went over 3/4 of the way towards hot.

malcolm