cook1e Posted March 24, 2014 Share Posted March 24, 2014 The mixture adjustment on the front Stromberg on the GT6 has been getting stiff for a while now. Went to tune the carbs over the weekend and the hex socket needle mixture adjuster had totally seized, what's more when I tried to force it the hex socket rounded off so I can't adjust the mixture and it's running a bit weak. I can't even strip the needle assembly out to replace it as I think I need to undo the adjuster to do this which isn't possible with it rounded off!!So looks like I'll need to find a whole secondhand piston and needle assembly unless it's possible to get a new one. I'll give Andrew Turner a call to see if he has any suggestions.The car starts and runs but it's not revving cleanly under load, if I pull the choke out slightly to richen the mixture it runs OK. I've managed to tune the back carb OK using the colourtune... Quote Link to comment Share on other sites More sharing options...
MikeTeesside Posted March 24, 2014 Share Posted March 24, 2014 I've never been able to get mine right "by eye" or by setting it back to factory according to the book.They are curious and finicky creatures.Thankfully I have a Colortune on order and on the way. :) Quote Link to comment Share on other sites More sharing options...
BrendanD Posted March 24, 2014 Share Posted March 24, 2014 I have a friendly old school local mechanic who fine tunes with a CO meter for me. Quote Link to comment Share on other sites More sharing options...
Paudman Posted March 24, 2014 Share Posted March 24, 2014 8778 wrote:Thankfully I have a Colortune on order and on the way. :)Tuned mine recently with a Colortune and they’re now so weak it will hardly start… I never could get the hang of tuning a pair of these. Quote Link to comment Share on other sites More sharing options...
cook1e Posted March 24, 2014 Author Share Posted March 24, 2014 I've always had a fair bit of success with the colourtune to set the mixture in the past. My issue isn't setting the carbs up its dealing with the rounded off hex socket. I've found out its brass so no wonder it rounded off when the assembly seized up.The good news is that I've Found an article on the web today which explains how to get the needle out when the hex socket adjusting screw has rounded off ;-http://www.bowtie6.com/other/zenith-stromberg-carburetter-repair/So looks like I'll be able to sort it now, just need to order up the screw and anything else that needs replacing.... Quote Link to comment Share on other sites More sharing options...
Slowdown Posted March 24, 2014 Share Posted March 24, 2014 Many thanks for the link, Cook1e - I've been wondering for a while how to replace that O-ring. Quote Link to comment Share on other sites More sharing options...
MikeTeesside Posted March 25, 2014 Share Posted March 25, 2014 490 wrote:Tuned mine recently with a Colortune and they’re now so weak it will hardly start… I never could get the hang of tuning a pair of these.I've been told even with Colortune it's still not an exact science.Colortune will only give you the stable range, but your carbs may be happier at the top or bottom end of that range. Quote Link to comment Share on other sites More sharing options...
MikeTeesside Posted March 27, 2014 Share Posted March 27, 2014 Small update.. colortuned the carbs today and the car runs better than it ever has.Two thumbs up for an excellent product.I have been told the OLD colortune was a bit hit and miss and generally crap, but the NEW one is awesome. (dance) Quote Link to comment Share on other sites More sharing options...
DougBGT6 Posted March 28, 2014 Share Posted March 28, 2014 I have a VERY old colour tune and I can confirm it ain't too good! I use a vacuum gauge for tuning and timing, dead easy even with twin carbs. http://www.classic-car-magazine.co.uk/articles/tuning-with-a-vacuum-gauge.html Quote Link to comment Share on other sites More sharing options...
Martins Stag Posted March 29, 2014 Share Posted March 29, 2014 Andy perhap you ought to consider coming over to HS6 carbs then you won't have alll these issues? 8)Martin Quote Link to comment Share on other sites More sharing options...
Paudman Posted March 29, 2014 Share Posted March 29, 2014 4502 wrote:Andy perhap you ought to consider coming over to HS6 carbs then you won't have alll these issues? 8)MartinI myself may also need to - I can’t get mine to run anyway decent at all. If I set the mixture correctly (Colortune???) then the idle won’t go below 1100 rpm without dying; if I rev the engine when idling it immediately dies once the accelerator is released. I’m getting fed up of going to shows with the clutch and accelerator half in to keep the revs up, then idling as if the engine is coming out through the bonnet. Any thoughts? Twin Strombergs on a Gt6 Mk1…. Quote Link to comment Share on other sites More sharing options...
MikeTeesside Posted March 29, 2014 Share Posted March 29, 2014 Stroms do seem to be either flawless or picky as hell. Mk1's especially.Mine are running nicely now but I have to use choke to start the car, as all the tuning was done on a hot engine.More important to get hot running correct than cold running though. Quote Link to comment Share on other sites More sharing options...
.thumb.jpeg.b15b81ef10abeea1c3039ae03c4a9f3a.jpeg)
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.