GT6 Performance

[FalconWood]

Hi All. I just bought a Triumph GT6. The car is 1973 Mk3. It has not run for about 18 months but is in lovely body condition (rebuilt around 8 years ago and all pictures show extensive restoration) and the engine has had lots of attention over the years. BUT it isn't running well. The car idles at 1200 rpm (should be circa 800). At 60 the engine is running at 4000 revs. I struggle to take it behind 70 mph and it feels like its dragging weights behind it. It also smells a bit fumey and I can't help but think its running on a rich fuel mixture. I also wonder if as the engines revs its actually getting power to the wheels - just feels odd - possibly slippy clutch - just don't know. There aren't many Triumph garages around here (!!!) and a I don't know of any reliable and honest classic car engine/tuning types either - I live near Preston Lancashire. Any ideas and thoughts would be welcome.Thanks Chris

[PositronicRay]

Start with a full service, then attend to any niggles this throws up.

I'm not that familiar with the GT6 suspect 4k @ 70 may not be about right, maybe a slight tach error.

[finlo]

Does it have overdrive?

[FalconWood]

finlo said:

Does it have overdrive?

Yes it does. And when it is engaged in 4th and you press accelerator to push on from about 60mph you can feel it slip and jump out.

[FalconWood]

PositronicRay said:

Start with a full service, then attend to any niggles this throws up.

I'm not that familiar with the GT6 suspect 4k @ 70 may not be about right, maybe a slight tach error.

yes I will take it for a service and get all HT and plugs etc changed and then retune also. I hope that that does the trick. Will let you know

[FalconWood]

Started with ignition. Will do fuel and air next. Replaced plugs (very oiled and clearly years old) HT leads, distributor cap, points and rotar arm all replaced. Checked and noted running on 12’ ATDC. Adjusted to try 8’BTDC and after a few runs settled on 10’ BTDC. Runs much much better now but still more performance to come when I recon carbs etc I am sure. What’s changed. Well it starts first time and it idles better. The car pulls from 60mph much more easily. Much better all round. Most importantly I am doing this with my 17 year old son at weekends when he is off school and we are lovin* it!!!!Keep you posted.

My lad getting his hands dirty and lovin it.

[Mr2Mike]

I'd recommend investing in one of the electronic points replacement modules.

Are they Stromberg carbs? If so check the state of the rubber diaphragms, if these split it really hurts performance and general running.

[E-bmw]

If you are sticking with the current dizzy for the moment also check the vacuum advance works & ensure there is oil in the carb dash pots, this can cause poor running.

[tapkaJohnD]

FalconWood,

All good advice above, but you may enjoy going to a specialist Triumph site too.

Many GT6 owners on:
Club Triumph: https://club.triumph.org.uk/menu/1/view

TSSC: http://forum.tssc.org.uk/

But they may require you to join the Club and register. so

Sideways Technologies is an open Triumph site: http://sideways-technologies.co.uk/forums/

John

PS and there is a Triumph Forum here on PistonHeads too.

[PositronicRay]

Well done for getting the lad involved.

It takes me ages to get cars up to std, it's holistic, once you do though every trip is satisfying, you've bonded and understand. I always remember a passage from Jupiter's Travels, where he's riding along and can "just feel" everything's right, from the exhaust note to the suspension.

[FalconWood]

Thank you everyone for the replies. I topped up the oil in the carb piston as it was damp but nothing in it. I bought new parts for the SU rebuilds and that’s the next job. I 8ntend joinin* th3 Triumph owners club too in due course. Will keep you posted.