Starts only with starter fluid

[hush]

So I have this "free" 2008 Hyosung SB50 Super Cab scooter I was given and so far the bill is $650 way more than the bike is worth really but I like saving old bikes so I keep throwing money at them. So far I have replaced carb with new one from Korea, ignition, reed valves, battery and tires plus stripped it to frame and repainted it. Here is the problem, it will only start with a squirt of ether (starter fluid) and then it runs quite well even idles. I have had the top end apart and removed piston to check rings and bore but both are ok, initially I thought the problem was lack of compression but that does not seem to be the case, I only guessed at that as I figured the lack of compression was preventing the vacuum tap from opening and supplying fuel. Does anyone have a thought on what my issue could be? I have removed the engine 3 times to bench it, cleaned out the carb 8 times just to ensure it wasn't something easy like the slow idle jet blocking.

[jellywrestler]

So I have this "free" 2008 Hyosung SB50 Super Cab scooter I was given and so far the bill is $650 way more than the bike is worth really but I like saving old bikes so I keep throwing money at them. So far I have replaced carb with new one from Korea, ignition, reed valves, battery and tires plus stripped it to frame and repainted it. Here is the problem, it will only start with a squirt of ether (starter fluid) and then it runs quite well even idles. I have had the top end apart and removed piston to check rings and bore but both are ok, initially I thought the problem was lack of compression but that does not seem to be the case, I only guessed at that as I figured the lack of compression was preventing the vacuum tap from opening and supplying fuel. Does anyone have a thought on what my issue could be? I have removed the engine 3 times to bench it, cleaned out the carb 8 times just to ensure it wasn't something easy like the slow idle jet blocking.

whay not use the original carbie?

[F5 Dave]

Is the choke cct actually working? No choke will be very hard to start. It's actually an enricher not a true choke, but semantics.

[hush]

whay not use the original carbie?

It leaked due to float level valve being worn out and plastic mount is non adjustable, I bought new original carb and tried to swap parts but still leaked so area must have been worn out.

[hush]

Is the choke cct actually working? No choke will be very hard to start. It's actually an enricher not a true choke, but semantics.

That occured to me too as I drifted off to sleep last night, the bike displayed same issue with both carbs so problem followed replacement. Today I tested the cable feed to the auto-choke but there is no power? From the wiring diagram it feeds from the white/red wire from Regulator but could not get power there either, replaced regulator with a spare and still no power to choke, I am wondering if I can run power directly to the auto-choke to see if that makes any difference?

[F5 Dave]

I dreamed of Vixens, breasts straining under shiny armour.

[jellywrestler]

I dreamed of Vixens, breasts straining under shiny armour.

and pubic sideburns hanging out the side of their armour too, they didn't trim back then, a bit like the huntly women now.

[hush]

So the auto choke actually does read volts (6.4) when the engine is running but not sure how strong that is going to make the auto choke work, I have decided to buy a manual choke, that way I can test to see if the choke has any real affevt on starting.

[hush]

So fitted the manual choke and the bike starts first time every time which is a bit annoying as I replaced the carb, air filter and reed valve and had the engine out disassembling the top end twice. I think the reg/rect is bad, I fitted a second one I had but as both these scooters had been lying out in all weathers for years I'm pretty sure that one was bad too. Have ordered a new one. The reg/rec gets power from the generator then sends it to the auto choke so possibly the auto chokes (enrichers) are fine and once I fit the new regulator/rectifier I will be able to use them again.

[F5 Dave]

So do you have a multi meter? A cheap one will do ok will tell you if you are getting a decent voltage to the battery..

But you've learnt where the problem lies (choke) so that's great progress.

[SaferRides]

We've all been there. Last year I had intermittent starting problems that became less intermittent after a while. I somehow convinced myself it wasn't the starter relay, which it was. In my defence, it was almost random, and of course always came right before I could take the seat off and check voltages.



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[jato]

you may find the auto enricher is closed [turned off ] after the engine has been running for a minute or two . my outboard works like that, with the electric element slowly closing the cold start circuit. did the new carb come with a new auto enricher already fitted? they can have gum clog the fuel circuit

[BMWST?]

We've all been there. Last year I had intermittent starting problems that became less intermittent after a while. I somehow convinced myself it wasn't the starter relay, which it was. In my defence, it was almost random, and of course always came right before I could take the seat off and check voltages.



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Intermittent faults are the worst!