start up help needed pls

[Tzian]

Last night we got her started up with the choke on, pilot screws were on 2 turns, when she warmed up taking the choke off she wouldn't hold idle just kept dying, so turned the pilot screws to 1&1/2, next time she idled just long enough for us to do the balancing (it was very near anyway), then dropped low and died, then we could not get her started again and called it a night cos it was getting late and we have neighbours.

After rereading some stuff we started at it again today, got her started on the choke, as she got warmer her revs increased, tried taking the choke off and she dies, seemed to be in line with what is said for too rich still, so set the pilot screws down 1/2 a turn and tried again, won't have a bar of trying to start like that, so put them back to 1&1/2

Got her started and she was running, thought great, but she wasn't smooth, looked at the vacuum guages and no.2 was lower than the others, so i went to adjust, her revs picked up and she started to sound a lot smoother, not perfect but much better, a little more sounding even better but revs were up to 3k, so i went to turn the main idle adjust screw down a touch and she died, now we can't get her to start again


any thoughts? letting her cool down before trying again, maybe she got a bit too hot, we have the best fan we own blowing on her but it's warmed up here a bit today, would appreciate any thoughts you have tho to add to the reading i am doing while waiting for her to cool down

regards and thanks

[gustovh]

Carb mount O rings probably bad. Had running issues once that no matter what I did noting worked until I changed the float bowl gaskets, then I had a new machine.

V

[chuck hahn]

Set some house fans in front of the engine on the highest speeds and you can just let it run. On CV carbs turning the mixture screws IN will LEAN the cylinder. OUT , obviously, would be RICHENING the cylinder.

Setting the screws at 2 to 2 1/2 out shouldnt make the bike stall. Be sure the chokes are falling and closing completely..now that WILL make it choke out. May have to pull the carbs and use a rolled up green scotch brite to clean the bores the choke plungers go into. Scale and crud build up in the holes can make the choke plungers hang up. Polish the drums on the plungers with some 000 grade steel wool..and get the little end point thing clean as well.

Also, look at the rubber seats on the plungers for cracks. The bike will idle best at around 1200 RPMs in spite of the usual 1000 recommended in the manual.

And I second the intake manifold orings...did you replace them? Sure they are in the grooves and not pinched beteewn the head and flanges??? It does happen. And what about the manifolds themselves? Cracks, peeling or sepertions make them leak air.

[Tzian]

carbs have been fully cleaned, new jets, gaskets etc etc installed all working properly no blockages, new o rings on boots already done


have tried starting her at various points now, going 1/4 turn at a time, with choke (she was still warm but not hot) nowt, without she would kinda think about it so turned it in (leaner) a bit, trying at each stage, still not success till we get to the opposite where she was trying on the choke but not off

had this running last night and this morning just cannot seem to replicate it

[chuck hahn]

I have dipped carbs for the full 24 hrs as prescribed and STILL had to clean the holes the plungers go in because they felt like they were scraping and didnt snap back freely when tested. The fix was to clean the holes with the pot scrubber. Just because they were dipped doesnt mean there isnt crust and crud still clinging on.

Now, since that one experience, the holes get a good MECHANICAL going over as well so as to not have the hanging choke represent itself. Not saying this is your problem..but it is something to consider.

[chuck hahn]

What about the slide diaphrams? Installed right? Did you check for pinholes? Put a flash light behind them and look for any light specs shining through the rubber.

[Tzian]

yep checked diaphragms, if it moved i checked and double checked

surely tho she wouldn't want choke when warmed up, so why can't i get her to start then, starting with choke cold was ok

[chuck hahn]

My question was about damage and condition..not whether they move. Yes they can move and still have leaks that at lower RPMs make them stumble or fail outright. they will run OK with the higher intake pressures created with the higher RPM needs..then fail at lower RPMs as the pressures in the venturis fall to a level that the leaks cant be overcome....follow me???

In other words it like an inner tube withn a hole. if the compressor can put air in faster ( or at least equal to the amount escaping ) the tire wont go flat. Slow the air input lower than the leak and the tire fails..get it??

[Tzian]

my answer was not about the diaphragms moving, sorry bad typing in a hurry, yes i checked the diaphragms for holes etc couldn't find anything wrong with them at all, seriously hope its not some inperceivable blinking hole causing all this

and yes i checked that everything that was supposed to move did in fact move and freely



right had another go, now waiting for battery to charge again gonna kill my battery at this rate


i would say room temp engine to touch so not exactly cold, choke on - started up, revved up to scary levels, push choke in to reduce revs to 3k, any lower and dies at this point

started to warm up then just died,

since won't start, if the pilot screws are on 2 or more turns then choke on, she won't even try a thing, choke off sounds she is trying, that to me sounds like she is still set too rich, am i wrong in that thinking?


when we did get her started last night and this morning she was both times cold and set on 1/1/2 turns and it was with choke on

[Spyderman]

i would say room temp engine to touch so not exactly cold, choke on - started up, revved up to scary levels, push choke in to reduce revs to 3k, any lower and dies at this point

started to warm up then just died,

since won't start, if the pilot screws are on 2 or more turns then choke on, she won't even try a thing, choke off sounds she is trying, that to me sounds like she is still set too rich, am i wrong in that thinking?


when we did get her started last night and this morning she was both times cold and set on 1/1/2 turns and it was with choke on

I'm thinking that your still on the lean side try 3 turns on the pilot screws and see what happens

[Spyderman]

from the sticky carb spec thread

GS550 (80-82) the specs are for the CV's

idle r/min 1100-+/-100r/min
carb mik bs32ss (4 seprate carbs)
id no 47160 (us) 47170 (can)
bore size 32 (1.26)
float height 22.4.+/-1.0 (0.88 +/-0.04)
fuel level 5.0+/-0.5 (0.20 +/-0.04)
main jet #92.5
main air jet 1.6
jet needle (4bel2 us model) (5f42-3rd notch canadian adjusable needle)
needle jet x-6
pilot jet #40
throttle valve #135
by pass (0.9, 0.7, 0.7 us model) (1.0,0.8,0.8 canadian)
pilot outlet 0.7
valve seat 2.0
starter jet #35
pilot screw 3.5 turns back (mixture screw)
pilot air jet (us model #150) (#120 canadian)

these setting apply to all 550 models with the CV style carbs,
Me personaly would try to get the carbs as close to the the canadian specs as possable the US models were lean out so much to meet emissions. the candian specs give the bike a hardier fuel supply.

[chuck hahn]

And heres a good little read on CV carb tuning. Forgot I had it in my favorites.

http://www.factorypro.com/tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html