Colin Lindsay Posted March 21, 2021 Report Share Posted March 21, 2021 5 hours ago, Tipidave said: Again, I think the dizzy is not original and I have no idea about the curve. I have purchased an old original and intend to send to distributor doctor when enough pennies are put by. 😀😀👍 Some dizzy figures that might help (bottom row) Link to comment Share on other sites More sharing options...
Tipidave Posted March 21, 2021 Author Report Share Posted March 21, 2021 I have just returned from an impromptu 150 mile trip. The car drives pretty well and fuel economy is much improved (around 45 per gallon now). Acceleration is still a bit lacking .... Contact gap set 0.015” giving 39 degrees dwell angle and valve clearances all adjusted. Set to 15 degrees advance at around 700 rpm with vacuum removed and blanked. Two remaining problems with the carb are... 1) drip of fuel from spindle under the float chamber even when. It isn’t more than warm. One drip every 10-20 seconds starts about 3-5 minutes after stopping engine. Some fuel draining from the manifold drain too. This stops after around 20 minutes or so. I did try leaving the stopped car with the choke out in the hope that this would open the throttle butterfly sufficiently to allow any fuel in the throat to drain through the manifold drain. I am puzzled as to the cause. But most concerned about the drip of fuel onto a hot manifold. 2)Throttle mechanism reluctant to return spindle to idle position so idle revs appear high (around 11-1300 at a gues). A quick blip on the throttle and it will usually then settle onto the idle stop. Definitely improved from yesterday! Link to comment Share on other sites More sharing options...
Tipidave Posted March 21, 2021 Author Report Share Posted March 21, 2021 Thanks for the distributor info Colin Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 21, 2021 Report Share Posted March 21, 2021 bear in mind dizzy stats are dizzy rpm so half crank rpm and the degs on crank are x 2 dizzy degs. most dizzy test data is done decelerating not accelerating the rpm there is a full set of test data in the triumph workshop manual think i would remove the float needle valve and give it a light tap with a small hammer to re seat it the mani drain tube is there to drain excess fuel from choke operation its supposed to be defunct for normal running i get the feeling this is an over fuelling problem what pump is fitted , is the fuel tank venting OK ( via the cap) pete Link to comment Share on other sites More sharing options...
Tipidave Posted March 21, 2021 Author Report Share Posted March 21, 2021 Yes tank is venting ... not sure about the pump. I will try to get a decent photo of it. I know it isn’t the original and irritatingly I cannot find it in my ‘bitsa’ box... but the pressure regulator in the filter is adjusted and working. there is no evidence of it dripping fuel while the engine is running... only starts a few minutes after cutting motor. I am pretty sure that this isn’t heat related because I have seen it do it even when engine is still cold/cool even after a long run today it was pretty cool to the touch. Is there any way for fuel from the accelerator pump circuit to disperse into the swan neck... I did witness this although some was also coming from the bridge. Link to comment Share on other sites More sharing options...
Tipidave Posted March 21, 2021 Author Report Share Posted March 21, 2021 Out of interest... is there any way to know that the float valve is seated at the correct height? Can it be measured relative to the edge of the carb body/lid? I have read about the need for different washers depending upon whether it is a plastic or brass float. In my case it is a plastic float. if the specific gravity of a modern fuel is sufficiently different from the old stuff... could the weight of the float now be incorrect? just a thought. I have now read severalrelated threads online, unfortunately none have reported a solution to the problem. Most just agree it is a problem associated with new fuels. with this in mind i filled up with the essohigh performance petrol which according to the essay web site does not contain any ethanol. thouughts? Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 21, 2021 Report Share Posted March 21, 2021 well theres a lot of myths about most fuel problems are crap rubber hose supplies we dont have anyone with ethanol dissolved carburettors or exploding pump bodies will have a browse about float heights in the morning Im too enthused with the crap TV to go and have a look there will be a dimension from the top face ....watch this space he says !! certainly the higher ron fuels have less or no ethanol added ...guess its coming pete Link to comment Share on other sites More sharing options...
Tipidave Posted March 22, 2021 Author Report Share Posted March 22, 2021 I may be into the right track... it seems that today’s fuel is a significantly different specific gravity which results in the float floating higher in the fuel... which in turn raises the level of fuel in the float chamber. therefore I plan to put an additional washer under the valve to lower the fuel level a bit and see if it has an effect. Does this sound like a sensible idea?? Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 22, 2021 Report Share Posted March 22, 2021 well worth a try , is the needle valve a new one or old one ??? i cant find a height spec anywhere heres a load of useless clues b30pse1.pdf Link to comment Share on other sites More sharing options...
Tipidave Posted March 22, 2021 Author Report Share Posted March 22, 2021 Ta muchly ... I am optimistic that in the right path now! Any info is useful 😀😀👍 Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 22, 2021 Report Share Posted March 22, 2021 its fact many manuals and data sheets always miss out the one small bit of essential data you are needing happens a lot Pete Link to comment Share on other sites More sharing options...
Tipidave Posted March 22, 2021 Author Report Share Posted March 22, 2021 I shall work it out... it will be a process of trial and error... as a friend of mine tells me.. something will happen .... something always does 👍👍😀 Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 22, 2021 Report Share Posted March 22, 2021 well its lock down you cant go out much so sit back have stiff coffee Pete Link to comment Share on other sites More sharing options...
GrahamB Posted March 22, 2021 Report Share Posted March 22, 2021 I have never used a fuel supply regulator but this reminds me of a problem we had with a regulated water supply. The equipment needed a supply pressure of 15 psi which was controlled by the regulator. However, when the equipment was turned off, a slight leak in the regulator allowed the downstream pressure to gradually increase upto mains pressure. When the equipment was turned back on, the flow was much greater than the leakage so the pressure returned to 15 psi. If there was a slight leak in the fuel regulator, on stopping the engine, the pressure on the needle valve would slowly increase to the residual pressure in the pump caused by the return spring acting on the diaphragm. This could possibly cause a couple of cc of petrol to flow into the carb. May be relevant if all other causes are eliminated. Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 22, 2021 Report Share Posted March 22, 2021 Graham thats a good clue, so they are another Must Have you dont need to MUST back to a base pump overkill can you fit your pressure gauge in the line to see whats really going on especially when you stop the engine ?? Pete Link to comment Share on other sites More sharing options...
Tipidave Posted March 22, 2021 Author Report Share Posted March 22, 2021 Yes I will do this. I will try my shim under the float valve first. next I may try to clamp the fuel out from the regulator and see if it still happens. finally I will see if I can get an original mechanical fuel pump band a new run of copper fuel pipe. thanks for the ideas... keep em coming 😀👍 Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 22, 2021 Report Share Posted March 22, 2021 can you not just pull the hose from the carb i suspect on this is a sleeve nut and spanner so ....Nah ! we're full of ideas ..just none work Ha ! Pete Link to comment Share on other sites More sharing options...
Tipidave Posted March 22, 2021 Author Report Share Posted March 22, 2021 If I need to buy an original fuel pump, some olives and new copper pipe... where would you get them from? Link to comment Share on other sites More sharing options...
Tipidave Posted March 22, 2021 Author Report Share Posted March 22, 2021 My connection from copper pipe to flexible hose is now leaking... so I will need to sort that out first 😳 Link to comment Share on other sites More sharing options...
Colin Lindsay Posted March 22, 2021 Report Share Posted March 22, 2021 8 minutes ago, Tipidave said: If I need to buy an original fuel pump, some olives and new copper pipe... where would you get them from? James Paddock. https://www.jamespaddock.co.uk/fuel-system-5?pagenumber=2 Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 22, 2021 Report Share Posted March 22, 2021 canley classics or james paddock or any of the main stream eg https://www.jamespaddock.co.uk/fuel-pump-5 Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 22, 2021 Report Share Posted March 22, 2021 Colin...Snap Ha! 1 Link to comment Share on other sites More sharing options...
Tipidave Posted March 22, 2021 Author Report Share Posted March 22, 2021 Thanks for that... I have ordered a new pump and fuel pipe kit. Will try to set everything back to standard. Link to comment Share on other sites More sharing options...
Tipidave Posted March 23, 2021 Author Report Share Posted March 23, 2021 Today. I have learned some more. Firstly, after my long run at the weekend, and following use of a colourtune plug today i have determined that the mixture is running rich both at idle and at higher revs. My neighbour also watched me off up the road and said there was a small black puff from the exhaust as i accelerated away and changed from first to second. Also when half way through my 150 mile trip at the weekend i stopped and inspected number 4 plug and whilst not the worst i have seen it was definitely a bit sooty, rather than a nutty brown. This was after 90 miles of relatively high speed (i use the term loosely)running. given the limited number of adjustments available... does this support the notion that the level in the float is high? or could a timing/ spark issue give the same? anything else? Valve adjustments re checked and found to be spot on. Link to comment Share on other sites More sharing options...
Pete Lewis Posted March 23, 2021 Report Share Posted March 23, 2021 you will always get a puff of smoke every time you operate the accelerator pump so on gear changes ...yes retarded or insufficient advance reduced efficiency and again sooty ..yes the 1147 was never a lean burning unit as well before emissions took hold puling a plug needs to be done after alight throttle steady cruise , and coast/eng off to a layby to check rich at idle is back to screw the volume screw in to best running the idle circuit stops working as soon as you open the throttle it has no effect on road running throttle mixture rich at high revs on alight engine/no load i would expect that on a colour tune they really are not a lot of use in real engine operation and open the throttle this squirts the accel pump and yellow flames quite normal i would advance by ear then you drive with less throttle for the same power ...and may be get a win from all this idea do you have a vacuum gauge you can tap in the manifold should read 18 to 21 in/hg at idle below 18 and its retarded Pete Link to comment Share on other sites More sharing options...
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