Very helpful. I met John around 85 or 86 I think when he restored the carbs on my Dad's '69 B. We drove up to his shop from Chicago to pick them up. The bodies were glass beaded and the bowls polished. They were beautiful. I just picked up a '72 BGT that has been parked for 3 years, so a tune and carb sync is on the horizon.
awesome video, i'm over in australia and your video really helped me out tuning the carbs on my engine which is 202ci holden straight 6 in a holden torana and it runs 3 of the same model SU'S in your video, thankyou so much.
OH , Btw, Im trying my SU Carb Tuning atm, and i cant get it right, everytime i lift the piston it either just stumbles or rises then stumbles to an almost stall, is the "rises and stumblesto an almost stall" what i should be looking for? because iv always assumed that the engine should go back to its normal idle when lifting the piston
TOOO bad you guys are over seas, My Triumph 2500 TC could use a little work!, I just replaced the clutch only to find it wasnt the release bearing making the noise.. the gearbox is naffed, also, it needs one hellova tune as its been sitting for so long!
I have got a very good hint for you to keeping the nice old Engine in good shape with todays ultra dry eco fuels: Use 1:100 API TC two stroke oil / fuel mix as regular driving fuel, that keeps the old fuel-system gaskets, rubber parts, alloy parts etc... and cast iron metal surfaces of those vintage engines in excellent shape...and it also lubricates the valves and upper piston regions. Most Porsche vintage owners in Germany do so Also keeps carbs/injection and tank clean and rustfree!
This is a great video!!!. I used your tips on my austin mini cooper with SU H4 carb. It runs great now. But after I install the K&N air filter, it runs like the carb is flooding. Can someone help???
Two other additions to the balancing of HIF's at idle and fast idle versus at higher speeds:
1) after a long time, the two soft springs pressing against the two pistons may become unequal in length/strength. The mixture at higher throttle then comes out of balance. They come cheap, so in doubt renew......
2) looking at the color of the spark plugs after a long drive on the highway gives a perfect indication of balance in mixture at higher throttle. A quarter turn left or right is often enough.
I used to own an MGB GT back in the 80's, my method of tuning the carbs after making sure all other aspects were OK, ie timing, mixture, etc was to use a piece of rubber tubing and listen to the 'Hiss' on each Venturi. I used to adjust each carb so that the 'Hiss' was equal on both. A bit of a Red Kneck approach but it worked for me.
a great video for removing the mystery for apprentices. Important to adjust throttle plates to balance first for me. Regards to John Twist. Note should be made to Burlen Fuel Systems, England who are the current SU parts source.
Great starting point for all, but a bit oversimplified. The adjustments assume that each carb has the proper needle and the same air flow:rpm curve. The video shows correcting fuel mixture and balancing airflow at idle. But once the engine is under load and higher in rpms, the mixtures can be vastly different than as set at 800rpm no load. To get this correct requires a chassis dyno. I like to at least check the airflow again at 3500rpm and adjust the throttle plates to balance, if needed.
Very helpful. I met John around 85 or 86 I think when he restored the carbs on my Dad's '69 B. We drove up to his shop from Chicago to pick them up. The bodies were glass beaded and the bowls polished. They were beautiful. I just picked up a '72 BGT that has been parked for 3 years, so a tune and carb sync is on the horizon.
bankerdanny 3 months ago
I'm about to tackle the triple HS4 set up on my ride... not for the feint hearted...
ScimitarCoupe 10 months ago
awesome video, i'm over in australia and your video really helped me out tuning the carbs on my engine which is 202ci holden straight 6 in a holden torana and it runs 3 of the same model SU'S in your video, thankyou so much.
kymt1979 11 months ago
Is there a vide of How to tune the hitachi su for a datsun 240z
joshoelrey 11 months ago
OH , Btw, Im trying my SU Carb Tuning atm, and i cant get it right, everytime i lift the piston it either just stumbles or rises then stumbles to an almost stall, is the "rises and stumblesto an almost stall" what i should be looking for? because iv always assumed that the engine should go back to its normal idle when lifting the piston
bloodreighn 1 year ago
TOOO bad you guys are over seas, My Triumph 2500 TC could use a little work!, I just replaced the clutch only to find it wasnt the release bearing making the noise.. the gearbox is naffed, also, it needs one hellova tune as its been sitting for so long!
bloodreighn 1 year ago
wonderful now my MGB run so smoothly thanks to you ,very professional tuition
DariaOvermars 1 year ago
Brilliant video's! You've explained everything so well and no xxxx either. Thanks these video's have been a great help.
steviesilvermint 1 year ago
This has been flagged as spam show
I have got a very good hint for you to keeping the nice old Engine in good shape with todays ultra dry eco fuels: Use 1:100 API TC two stroke oil / fuel mix as regular driving fuel, that keeps the old fuel-system gaskets, rubber parts, alloy parts etc... and cast iron metal surfaces of those vintage engines in excellent shape...and it also lubricates the valves and upper piston regions. Most Porsche vintage owners in Germany do so Also keeps carbs/injection and tank clean and rustfree!
Klottelitsch 1 year ago
that was very easy vid he says everything in plain english and makes it look so easy gary in the uk
MrGazawilliams 1 year ago
if i lived local id bring my mini to you in a heart beat,you adjusted those beautifully.
spiralisedcat 1 year ago
really useful tutorial!....thanks a lot
withapulse 2 years ago
great video John, just need to find a uni-syn tool in nz now!
jamescameron082 2 years ago
hi....I'm converting my fuel injected xj6 jag to triple SUs,,,,,can you let me know iof you source that tool....looks better than the hiss test
withapulse 2 years ago
This video is very educational , thanks!!!
germomr2 2 years ago
This is a great video!!!. I used your tips on my austin mini cooper with SU H4 carb. It runs great now. But after I install the K&N air filter, it runs like the carb is flooding. Can someone help???
bootss77 2 years ago
@bootss77
Taken into account the ease/or more difficulty for the engine to suck the air in? probably reduced the vaccuum effect somewhat.
LIP15 1 year ago
Great video - just used some of these tips to get my P6 Rover in a driveable condition - thanks!
LashoutUK 2 years ago
Thanks man
The beast tuning video
Iam going to try it on my 240z
Sulaimaa 2 years ago
@Sulaimaa hey im watching this video because I also need to tune the carbs on my 240z. How did it work out for you?
Decoy8 1 year ago
@Decoy8 Hey man, it worked at the start (2 days) but it went to the same old story.Finally I converted to turbo engine(RB25DET)
Good luck for you.
Sulaimaa 1 year ago
The tool is called a UNISYN.
It's a Carb balancing & flow meter
Available at Moss Motors or Victoria British
mbamgb 2 years ago
whats that tool hes using to gage airflow?
1ajs 2 years ago
This Video made me feel better about working on my MG
christ04equipment 3 years ago
Two other additions to the balancing of HIF's at idle and fast idle versus at higher speeds:
1) after a long time, the two soft springs pressing against the two pistons may become unequal in length/strength. The mixture at higher throttle then comes out of balance. They come cheap, so in doubt renew......
2) looking at the color of the spark plugs after a long drive on the highway gives a perfect indication of balance in mixture at higher throttle. A quarter turn left or right is often enough.
donthuis 3 years ago
Much easier to understand than reading in a manual. Thanks.
peckerwood57 3 years ago
I used to own an MGB GT back in the 80's, my method of tuning the carbs after making sure all other aspects were OK, ie timing, mixture, etc was to use a piece of rubber tubing and listen to the 'Hiss' on each Venturi. I used to adjust each carb so that the 'Hiss' was equal on both. A bit of a Red Kneck approach but it worked for me.
mikelsok 2 years ago
brilliant
alfa01spotivo 3 years ago
a great video for removing the mystery for apprentices. Important to adjust throttle plates to balance first for me. Regards to John Twist. Note should be made to Burlen Fuel Systems, England who are the current SU parts source.
rollsroycemechanic 3 years ago
Muy lindo !! Gracias,desde argentina.
bellinivernon 3 years ago
Excellant and super informative (for a diy mechanic anyway) Would I do exactly the same sequence/procedure for a Rangerover Fitted with HIF44's?
allmuktup 4 years ago
thank you again mate love your info
mgazone 4 years ago
Are the SU's on a '70 done the same?
snoski1 4 years ago
Great starting point for all, but a bit oversimplified. The adjustments assume that each carb has the proper needle and the same air flow:rpm curve. The video shows correcting fuel mixture and balancing airflow at idle. But once the engine is under load and higher in rpms, the mixtures can be vastly different than as set at 800rpm no load. To get this correct requires a chassis dyno. I like to at least check the airflow again at 3500rpm and adjust the throttle plates to balance, if needed.
SmhsMark 4 years ago
It's also important to make sure that the pistons rise the same amount when you open the throttle
Agouti 4 years ago
very good video!
Could you maybe make a video about the Weber tuning? I'm building 45 DCOE on the B's engine right now...
M3addicted 4 years ago
Another excellent John Twist Video -- a must for anyone that has an MGB
DaveGalligan 4 years ago
great help.
lkosatka 4 years ago
Outstanding, Thank you
Barry, MGCCT
bshnabel 4 years ago