HS6 rebuild kit/ needle option
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Member Number 7392 04/07
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
Re: HS6 rebuild kit/ needle option
Further update. So the weekend just gone the S.U s were reinstalled, reset to base values as per several guides, along with all new gaskets etc.
Last night ( Mon 2 June ) went for a start up. Removed plugs etc for an ' oil up non fire start'. Once oil light went out , reinstated plugs leads etc. Pulled choke out, turned the key and BOOM shes up and alive again, albeit with a 1500 idle
. This remained even after choke pushed home. Couple mins later wound down the idle screws to lessen the rpm. No leaks, anywhere. I think i counted 12 possible leak points.
Knowing i still have to fine tune it, i thought this eve ( the next day) i will just go for a normal start. So i did just that. Chexked again for any damp patches ( none) so just sat in, pulled the choke right out, turned the key - BOOM she fired straight up - i would say the best start ever at a normal fast idle. Slowly pushed in the choke and it soon settled down. So.the plan is to do a fine tune at the weekend. I know its not 100% as it splutters etc when revved but pleased so far. Ive purchased a Gunsons balancer kit to help. Will post up again with my findings.
Last night ( Mon 2 June ) went for a start up. Removed plugs etc for an ' oil up non fire start'. Once oil light went out , reinstated plugs leads etc. Pulled choke out, turned the key and BOOM shes up and alive again, albeit with a 1500 idle

Knowing i still have to fine tune it, i thought this eve ( the next day) i will just go for a normal start. So i did just that. Chexked again for any damp patches ( none) so just sat in, pulled the choke right out, turned the key - BOOM she fired straight up - i would say the best start ever at a normal fast idle. Slowly pushed in the choke and it soon settled down. So.the plan is to do a fine tune at the weekend. I know its not 100% as it splutters etc when revved but pleased so far. Ive purchased a Gunsons balancer kit to help. Will post up again with my findings.
Member Number 7392 04/07
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
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Re: HS6 rebuild kit/ needle option
Hi Forkie,
" it splutters etc when revved "
What oil do you have in the dash pots? That's what it's for, to enrichen the mixture when you rev the engine by slowing down the piston rise.
It's good to hear you are making progress but I'm not sure about the 'BOOM' when you start it!
Cheers,
Mike.
" it splutters etc when revved "
What oil do you have in the dash pots? That's what it's for, to enrichen the mixture when you rev the engine by slowing down the piston rise.
It's good to hear you are making progress but I'm not sure about the 'BOOM' when you start it!

Cheers,
Mike.
(South Oxfordshire)
Register Member No 0355
1971 2.5PI Saloon Sapphire blue
1973 2.5PI Saloon rust some Honeysuckle
1973 Stag French blue
(1949 LandRover which is now back to its original light green!)
Register Member No 0355
1971 2.5PI Saloon Sapphire blue
1973 2.5PI Saloon rust some Honeysuckle
1973 Stag French blue
(1949 LandRover which is now back to its original light green!)
Re: HS6 rebuild kit/ needle option
Hi Mike - yes thankfully ' Boom' is only a phrase we use regularly at work when a task is completed on site so it kind of always sticks in my head
.
So - the always debated dash pot oil - ive been reading so many articles / watching videos on the carb rebuild and reasembly, also on here too with past posts - soo many differing opnions - so for now i have gone back to my engine oil ( from the can, not the engine before you ask
) , which since i have had it is what i have always used, more than likely after asking the P.O. what he had been using . I think maybe it is running lean, as when checking with the lifting pins the idle drops away, which after all my swotting up indicates a lean mixture. As a base line setting i leveled the jet to the bridge, marked one flat on each nut with tipex then wound the nuts down two complete turns - thats where they are currently.This weekend is allocated to the tune up - ive never done twin carbs before so am a little aprehensive but all i can do is try !!!! As said watched plenty videos. Just happy that all so far seems good - no leaks and nice to hear that Big 6 ' Booming' again 

So - the always debated dash pot oil - ive been reading so many articles / watching videos on the carb rebuild and reasembly, also on here too with past posts - soo many differing opnions - so for now i have gone back to my engine oil ( from the can, not the engine before you ask


Member Number 7392 04/07
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
Re: HS6 rebuild kit/ needle option
A couple of points that ive considered before the weekend tune up attempt - float level - mine are the solid plastic type float - no metal arm to tweak - ok - but no ' shims' sent from Burlens in the rebuild kit either - so am i assuming the needle is now a ' pre set ' affair - i have had no flooding of either chamber before, or after the rebuild so i will assume that is good news - i am sticking to my theory that the discovered stuck shut rear needle valve could be my issue.
The other point - choke setting. When i reconnected everything i made sure both jets were ' home' on connecting the choke cable back, ensuring a tad of slack when choke pushed home. The lad and me have just gone out to double check ( engine cold, not run) that with the choke in, the jets are up. So what we did was one watching, the other pulling out the choke - there is a deffinate delay from pulling the choke out to dropping the jets - great - both are off when the choke is in - but there is a marked difference between the 2 carbs of the jet dropping when the choke is pulled. My question is do i need to set them even, before starting to tune them. The front carb jet drops before the rear....
The other point - choke setting. When i reconnected everything i made sure both jets were ' home' on connecting the choke cable back, ensuring a tad of slack when choke pushed home. The lad and me have just gone out to double check ( engine cold, not run) that with the choke in, the jets are up. So what we did was one watching, the other pulling out the choke - there is a deffinate delay from pulling the choke out to dropping the jets - great - both are off when the choke is in - but there is a marked difference between the 2 carbs of the jet dropping when the choke is pulled. My question is do i need to set them even, before starting to tune them. The front carb jet drops before the rear....
Member Number 7392 04/07
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
Re: HS6 rebuild kit/ needle option
So, here are my findings. Having decided to buy the Gunsons Carbalancer - i know, ive been reading its not the best but am aware of the dismal clearance from the strut to front carb i figured my best chance 'as a guide', coupled with the old skool length of hose for the hiss. Just as well i brought it though - baring in mind id set them both to base levels - they were MILES out
front was off the scale - 5 and out of the tube - rear - zero reading
ok - so i got work to do . Yes, i had released both sets of clamps to do this so they were independent. Had a right job getting a match.
I could almost match them, but as idle speed well too high, trying to lower them both together to get an acceptable idle would always cause the rear carb to read zero again
then i thought ' fast idle cam' yep - even though i am sure i backed them both off on the rebuild, the rear was off, but front was heavily on ??
So made sure they were both now right off, start all over again.... revving up between movements as well. So ended up both now fairly similar, but having the vibes both were lean i thought best link them back up and look at mixture. I had to enrich them both, i found that harder , trying to find the sweet spot. Idle still a little high but i decided as everything was so far out i will leave it at that for now, i need a break in our torrential rain to take it out for a drive, burn off some carbon, and go from there.


I could almost match them, but as idle speed well too high, trying to lower them both together to get an acceptable idle would always cause the rear carb to read zero again

So made sure they were both now right off, start all over again.... revving up between movements as well. So ended up both now fairly similar, but having the vibes both were lean i thought best link them back up and look at mixture. I had to enrich them both, i found that harder , trying to find the sweet spot. Idle still a little high but i decided as everything was so far out i will leave it at that for now, i need a break in our torrential rain to take it out for a drive, burn off some carbon, and go from there.
Member Number 7392 04/07
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
Re: HS6 rebuild kit/ needle option
So - went for a drive last night - absolutely no difference - still cannot pull this car uphill. New jets, poppet valved butterflies changed to solid types, the noted during strip down seized rear carb needle valve obviously changed for new, carbs balanced, followed all the guides for the carb rebuild etc etc. Was not wholly happy with the mixture settings - hence thought to go for a short 3 - 5 mile drive through all road conditions to clear the engine out. I was really hopefull that with the above in mind i would feel a difference - nope. If anything was slightly worse pulling up a hill - still the same lack of power but now coupled with popping from the exhaust - which as far as im aware indicates a weak mixture.
So ok - back we go. Took out plugs 2 and 5 - the electrode was just grey - dry, and grey, on both. ( Previously 2 was grey/ brown, rear was dry black). So both 2 and 5 now being the same colour i would assume indicates they are at least now balanced.....
I am now an expert in removing and refitting of the elephants trunk in double quick time to be able to tweak the mixture screws using a combination of the lifting pins and a Gunsons colourtune kit. It took i think 3 half flats on each by the end of play last night to put some ' soot' on to plugs 2 and 5 - by then the garage was very toasty - each movement was followed by a clearing throttle up. I was planning another test drive this eve after the tweaking but i ran out of steam tonight. Am i on the right track here, or am i completely missing something. It is very frustrating. I would of thought changing the seized float pin, going to solid butterflies and now having balanced carbs would of given me SOMETHING - but evidently not....
So ok - back we go. Took out plugs 2 and 5 - the electrode was just grey - dry, and grey, on both. ( Previously 2 was grey/ brown, rear was dry black). So both 2 and 5 now being the same colour i would assume indicates they are at least now balanced.....
I am now an expert in removing and refitting of the elephants trunk in double quick time to be able to tweak the mixture screws using a combination of the lifting pins and a Gunsons colourtune kit. It took i think 3 half flats on each by the end of play last night to put some ' soot' on to plugs 2 and 5 - by then the garage was very toasty - each movement was followed by a clearing throttle up. I was planning another test drive this eve after the tweaking but i ran out of steam tonight. Am i on the right track here, or am i completely missing something. It is very frustrating. I would of thought changing the seized float pin, going to solid butterflies and now having balanced carbs would of given me SOMETHING - but evidently not....
Member Number 7392 04/07
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
Re: HS6 rebuild kit/ needle option
How frustrating. I would go back a step now and check the ignition circuit, low tension and high tension together with the timing, coil points condensor etc.
Charles Harrison
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Register member 3095
Folkestone
Cherry Red Mk1 2000 Rally Car
Mallard Blue 2.5PI
Sapphire Blue GT6 Mk3
Vermillion Red Spitfire 1500
Pimento Red TR6
Inky Blue VW Passat B5.5
Silver Range Rover Vogue SE
Re: HS6 rebuild kit/ needle option
It is VERY frustrating. It has been like this since returning to the road a couple years ago , which it most deffinately was not like it before the long lay up - so i have always assumed the fault HAS to be to do with inactivity for so long ( it had been run from time to time however) and i also have felt it is fueling issue although no issues really found until the carb rebuild.
List of new parts so far :
Battery
Alternator
Coil
Spark plugs
Quality leads from CW
Dist cap
Fuel pump( (NOS)
Carb rebuild kit including solid discs
All fuel pipes(again)
Points not new now but were back along, small mileage on them and have been checked but will recheck.
Full Auto gearbox rebuild/ cable/ flywheel at a large expense.
Tappets checked - does sound a little tappy but always has - arent they all?
Fuel pump pressure checked - fine.
Compression check - all 6 reading 150
There probably bits i have missed but that just gives an idea of where we are, and none of that has made one iota of a difference. I dont get it.
Timing - yes, thats been on my mind - eveyone is saying she starts and runs too well for it to be out - but it has not been checked for 2 reasons - because she does start every time,hot or cold,and runs so well, and always has done, and secondly ,mainly, the distributor side of things has never been disturbed, so how could it now be out....but again i will check. Ive even considered head removal - maybe stuck valves - but surely that would of shown on the compression test? It is certainly costing me the rest of my hair, and the bank balance.
List of new parts so far :
Battery
Alternator
Coil
Spark plugs
Quality leads from CW
Dist cap
Fuel pump( (NOS)
Carb rebuild kit including solid discs
All fuel pipes(again)
Points not new now but were back along, small mileage on them and have been checked but will recheck.
Full Auto gearbox rebuild/ cable/ flywheel at a large expense.
Tappets checked - does sound a little tappy but always has - arent they all?
Fuel pump pressure checked - fine.
Compression check - all 6 reading 150
There probably bits i have missed but that just gives an idea of where we are, and none of that has made one iota of a difference. I dont get it.
Timing - yes, thats been on my mind - eveyone is saying she starts and runs too well for it to be out - but it has not been checked for 2 reasons - because she does start every time,hot or cold,and runs so well, and always has done, and secondly ,mainly, the distributor side of things has never been disturbed, so how could it now be out....but again i will check. Ive even considered head removal - maybe stuck valves - but surely that would of shown on the compression test? It is certainly costing me the rest of my hair, and the bank balance.
Member Number 7392 04/07
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
Re: HS6 rebuild kit/ needle option
Just a few points to add on, in case it helps, to help me, find my issue :
Current mileage 48300, from new - no reason to doubt that.
I am it's 3rd owner - 1st owner was Inchcape, as a demonstrator
in Norwich - mine is a very early 2500S Estate.
2nd Owner brought it from them at 18 months old, he kept it for 29 years until i brought it from him in 2006.
That P.O. had un unleaded head fitted during his ownership. To my knowledge - and looking at it - the entire engine has never been out.
Matching numbers car.
It has never ever failed to start, hot or cold, in my 19 years.
Absolutely never had any overheating issues - before lay up, or since back on the road.
So its not one thats had 15 owners , messed about with etc. Still has the original 8 track in it for example.
As an aside - you mentioned the condensor Charles - i would of replaced that as a matter of course back then - but have not since - remind me the symtoms of what can happen if they go bad - i am struggling to remember - i am thinking if its gone bad it will burn the points out - which would give more issues than what i have ?
Current mileage 48300, from new - no reason to doubt that.
I am it's 3rd owner - 1st owner was Inchcape, as a demonstrator
in Norwich - mine is a very early 2500S Estate.
2nd Owner brought it from them at 18 months old, he kept it for 29 years until i brought it from him in 2006.
That P.O. had un unleaded head fitted during his ownership. To my knowledge - and looking at it - the entire engine has never been out.
Matching numbers car.
It has never ever failed to start, hot or cold, in my 19 years.
Absolutely never had any overheating issues - before lay up, or since back on the road.
So its not one thats had 15 owners , messed about with etc. Still has the original 8 track in it for example.
As an aside - you mentioned the condensor Charles - i would of replaced that as a matter of course back then - but have not since - remind me the symtoms of what can happen if they go bad - i am struggling to remember - i am thinking if its gone bad it will burn the points out - which would give more issues than what i have ?
Member Number 7392 04/07
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
1975 TRIUMPH 2500S AUTO ESTATE IN BRG!
DON'T TIDY UP - LEAVE IT WHERE IT FELL!!
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