Adrian Posted September 17, 2018 Report Share Posted September 17, 2018 Hi all, since the initial fire up I haven’t had chance to fettle the engine but an attempt at starting today, eventually ( I think the fuel filter is allowing fuel to drain back so takes a long time to fire up), once going as soon as I drop the throttle it splutters to a stall. Now the only difference between initial and now is the air filters are on and the breather connected. There was a noticeable drop in revs when I connected the breather could it be a vacuum issue? I’d appreciate any insights. Thanks Adrian Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 17, 2018 Report Share Posted September 17, 2018 With the breather left open you get a fast idle due to letting air in, if connecting it up makes it stall then the slow run idle setting is in need of speeding up and the mixture may be miles out of adjustment Just what evolition of carb is fitted cd cds or later cdse I talke it you have smiths emissions valve or maybe not ??? Make sure the filters are not obstructing the holes in the carb front face and the choke does work and fully returns the choke cam CD or the starting valve on a CDS (just one on the front carb ) Pete Link to comment Share on other sites More sharing options...
Guest Posted September 17, 2018 Report Share Posted September 17, 2018 Hello Adrian, Regarding the fuel filter is it around the correct way with the arrow towards the carb flow and is it clean ?? I doubt the filter is allowing the fuel to drop back, but rather the fuel pump presuming you still have a mechanical unit. Worth considering a one-way valve in the fuel line. The fuel pump may also be the reason why the engine is failing to tick-over due to insufficient fuel delivery. With regard to potential vacuum issues, it may be the rubber diaphragm on the breather valve - if you have one. I would also check the carbs rubbers as well for issues. I see Pete has flagged, so I am certain he will be able to add some good pointers. Regards. Richard. Link to comment Share on other sites More sharing options...
Adrian Posted September 17, 2018 Author Report Share Posted September 17, 2018 They are cd carbs and no valve. Tbh the clip on the choke doesn’t seem to clamp terribly tight. It’s a new glass filter from the club shop on the right way located before the fuel pump. Out of interest what is the fettling order, timing, needle, idle, mixture, etc? Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 18, 2018 Report Share Posted September 18, 2018 What have you done with the carbs, Have got the mixture to a base setting like 3 turns down from fully up ie down from jet touching the piston? No valve ....so breathers are direct fit to the carb body .? Filler cap is sealing ok. No leaks on rocker gasket? Sounds like its set far to lean Pete Link to comment Share on other sites More sharing options...
Adrian Posted September 18, 2018 Author Report Share Posted September 18, 2018 Other than adjusting the needle as per first twiddle day no other adjustments made or screws turned (seem to be CD3 carbs no adjustment underneath). Before starting I suspected a rich mix as the plugs were fould with carbon. Yes the breather is direct to the carbs. The inlet manifold does have a blanking screw in need of seating properly, could that be it? Based on reading around I think Timing is the first adjustment prior to adjusting the carbs. When viewed from the side, should the piston fully close the air intake aperture, mine is about 5-10mm gap at base but falls freely after lifting. Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 18, 2018 Report Share Posted September 18, 2018 remind me earlier , i should remember but !!!!! yes we set the delrin washers on the needles flush ??? that should be a good start, the 5-10mm gap is that when idling ? yes it doenst mater what order you reset all the basics but getting the timing right first is a sound plan as changes will affect the idle as you alter the dizzy , advancing will speed idle up retard will slow the idle down idle screws on the carbs need to be around 1.5 turns in from just touching the case /fully shut. Pete Link to comment Share on other sites More sharing options...
daverclasper Posted September 18, 2018 Report Share Posted September 18, 2018 The carb big piston that alters the needle height should rest on the bridge (ie no gap) when engine not running. If is sticking, then the jet could need centralising to the needle (plenty info on the net about this and 150's in general, Buckeye is a good site). I have also had them sticking, when I have had the main top of carb off and had the diaphragm removed. To get This ok I have had to screw the top 4 screws a bit at a time alternatively, while checking with each turn of screw the piston is still dropping freely and backing of screw a bit and trying another. Bit of a faf. Of course if there is any crap in the bore, then this could make the piston stick. Like others have said, need to trawl through the basics, regarding set up, and no air leaks, etc. These are very simple carbs, and removing the internals, is straightforward (speaking about the early 150), not sure if the later's more involved Dave. Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 18, 2018 Report Share Posted September 18, 2018 daves correct for fixed needles but these will be biased(sprung ) There is nothing to centralise the jet is pressed and solid the needle can wag around to find its own position, biased needles were introduce ob stroms and su to improve the way fuel atomises from around the needle not just sucked out the back face all types must drop with a clunk onto the bridge .. engine off. Pete Link to comment Share on other sites More sharing options...
daverclasper Posted September 19, 2018 Report Share Posted September 19, 2018 Sorry about that Adrian. Dave Link to comment Share on other sites More sharing options...
Adrian Posted September 20, 2018 Author Report Share Posted September 20, 2018 No Problem Dave Did the timing, engine seemed to be advanced hence the poor starting, set to approx. 12 degrees BTDC now and running a lot smoother (probably knocked distributor after first start up). Still a bit uneven at idle even though revs are around 800. Having read some other threads I'll not pay too much heed to the carbon fouling as It's not had a decent run and even a short run is likely to cause a carbon build up. The one difference I have noticed is the front carb seems to cause a slightly wet deposit on the plug - does this mean too rich, if so is it a 1/4 turn anti clockwise using the adjuster tool? The carbs were balanced and tuned by Jigsaw in 2014 before I bought it (as they are racing focussed, perhaps they like it rich!). I was going to look at the idle adjusters but given the revs I don't think it would help. Checked the piston and it does seat on the base (its a natural gap from the taper at the bottom of the chamber) they fall freely to the bottom but not a clunk. Checked compression and got 150-160 across all 6 cylinders. Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 20, 2018 Report Share Posted September 20, 2018 think of the adjuster as a 'nut' you turn it clockwise and the thread raises the needle to richen anti clock and you unscrew the needle it drops and weakens if may pay to set the needle delrin washer level with the inner needle holder rather than the base of the piston so its just under the base not level with it Pete Link to comment Share on other sites More sharing options...
Adrian Posted October 12, 2018 Author Report Share Posted October 12, 2018 Before adjusting fast idle I thought id record the stalling to see if there are any tell tale issues you may identify. NB after the stall it took a lot of turning over for it to fire up again. A bit disappointed really given a brand new Lucas Dist with electronic ignition from the club shop. sorry it is recorded on edge. Thing going through mind are should I blank off the temperature compensators with the gaskets as it was before the rebuild? Keep fiddling with mixtures? Take the filter off and see if it starts better with just a pipe. Take it to a garage to sort or pay for Pete to visit? Thanks IMG_1267.MOV Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 12, 2018 Report Share Posted October 12, 2018 Cant open on this silly tablet thing so will use laptop in the morning witha coffee I will be in derby on the 23rd at the rolls royce heritage with a .load of triumphers , lichfield is not that far off, I dont think my crew would oblige to detour for a twiddle so with the best intentions i reckon I will have to pass on that idea But you never know , daft things can happen Pete with bus pass Link to comment Share on other sites More sharing options...
Adrian Posted October 12, 2018 Author Report Share Posted October 12, 2018 I work from home on Tuesdays so I could get the kettle on? Surely triumphers would like to see a gt6. Seriously though I understand it a long way home. Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 13, 2018 Report Share Posted October 13, 2018 we dont do serious !!!!! just about to watch the clip Pete Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 13, 2018 Report Share Posted October 13, 2018 firstly idle is slow take it up to 800/900 sounds lean , have you moved the needles up so delrin washer on the top end of the jet is level with base of air piston ??? Pete Link to comment Share on other sites More sharing options...
NonMember Posted October 13, 2018 Report Share Posted October 13, 2018 Agree with Pete, it sounds lean plus a little on the low side. If you still have the temperature compensators they may open up a fraction as the under-bonnet heat soak builds up while idling, which isn't a problem if you're a tad rich at idle but if you're lean it will lead to stalling. Link to comment Share on other sites More sharing options...
Adrian Posted October 13, 2018 Author Report Share Posted October 13, 2018 Another silly question but the books say the idle adjust is on the same side as the temp compensator, just above it. I can’t see anything that fits. Carb tags say 3432 l/r which is correct for the 150cdse. I assume the vertical screw on the throttle linkage is the throttle stop and the fast idle seems to make no contact with anything, hopefully in the 4th picture. Link to comment Share on other sites More sharing options...
NonMember Posted October 13, 2018 Report Share Posted October 13, 2018 The idle setting screw is this one: I don't know why the books say it's anywhere else. Your fourth photo looks like there's an alignment issue between the carbs and the throttle linkage, but the fast idle screw is correct not making contact when the choke is fully in. Link to comment Share on other sites More sharing options...
Adrian Posted October 13, 2018 Author Report Share Posted October 13, 2018 Oh no, not more issues. I only checked the needle setting. Everything else is as pre refurb Link to comment Share on other sites More sharing options...
Adrian Posted October 13, 2018 Author Report Share Posted October 13, 2018 Ok so after a mornings fiddling the update appears to be a little more promising. Firstly twiddled with the idle. Then did a colour tune on 1 and 6 (I know some of you say it doesn’t work well for modern fuel but I thought I’d try). Burn yellow so indicated rich so fiddled with the carbs until under reving I got blue. I adjusted in situ then took off to see position, as per photo. I suppose the exact position depends upon the needle size as well. Ticks over a lot better. What do you think? 4A3EF81E-B8B3-4BF6-84B6-C23D8498D407.MOV Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 13, 2018 Report Share Posted October 13, 2018 the books say the little washer is level with the base but that depends on where the jet is pressed in . so yes if its running better then it looks ok i dont understand why the throttle shaft links are so misaligned , with that degree of offset the springy link will soon fail the shafts should align with each other the link just makes flexi connector , is a shaft 'got bent ' or something daft is putting the carbs on the pee ?? Pete Link to comment Share on other sites More sharing options...
Adrian Posted October 13, 2018 Author Report Share Posted October 13, 2018 Here's the picture of the carbs as taken off. don't seem to see a kink. Here are the carbs after storage and prior to clean. Definitely seems to be a kink - could it just be one of the flexible joints? How to correct? Loosen push and prod until straight and tighten? Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 13, 2018 Report Share Posted October 13, 2018 Well yes, the connectors can be reformed if they induce some twist .they are quite tough little sods but do fracture if constantly if worked on the wonk. Make sure the stem of the spindle goes through the two legs of the Z Pete Link to comment Share on other sites More sharing options...
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