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Posted

Hi

I was already having an minor issue with the bike misfiring and losing power. Had to take it in to Yamaha (they bent me over) and have the carbs cleaned, new plugs.

She now runs well all the way through the gears when warm but in the mornings its taking up to 20 minutes to get it started through a mixture of bumping, turning over on starter (without killing it), and bumping again. It will stall on the tickover a good 3 or 4 times on or off choke. Full choke will not increase idle speed. If I rev it, it almost dies, then slowly increases to a rattly mid high range rpm without that deep pop/firing sound I would expect from a happy warm engine. Go back to start of the year and she would fire immediately with no choke even in the snow.

Then for the first few miles I'm having to give near enough full throttle to pull away and when changing gears.

After 10 minutes or so, she's flying and doesn't miss a beat? Starts first time every time for the next hour or so but after work, dead again and the cycle begins all over.

I'm lost?

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Posted

I only used to have to give mine 1/2 choke even in winter. Then ran it like that for 2 to 3 miles before shutting the choke off.

 

If i recall correclty, doesnt it have a 3 position fuel tap? You need to turn off the fuel tap as soon as the engine is killed, or it could be flooding the carb.

 

Another option is to take it back to the dealer, and say your not satisfied with the work. Yopu have to be specific with these people and tell them exactly what you want. If you just said to them, clean the carbs, thats all they will have done.

Posted

Airhead and NSD have good points but I would find out why the choke has no effect on idle speed? it should at least up the revs a bit, might be a blocked slow running jet. I know you had the garage clean the carbs but if they didn't take the jets out then they didn't really clean them. If it runs fine and starts fine when it's warm it has to be a slow/cold running problem in my opinion but either of the above could be a good starting point.

  • Like 1
Posted

Cheers for that. The choke does increase the idle speed once she is up and running, it just feels like there is a point where it suddenly kicks in as if it's suddenly woken up.

I did wonder about the fuel thing but it has never been a problem in the past? Which setting would be OFF as I thought the 3 positions were (12o'clock) ON, (3o'clock)PRIME, & (6o'clock)RES?

Posted

Nope, positions are: arrow pointing 6 o clock = ON. Arrow pointing 12 o clock = RES. Arrow pointing 3 o clock = PRI

 

Fuel Cock: This motorcycle is equipped with a negative pressure fuel cock. The fuel cock supplies fuel from the tank to the carburetors while also filtering it. The fuel cock positions are explained as follows.

ON: With the fuel lever in this position, fuel flows to the carburtetor when the engine is running. Turn the fuel cock lever to this position when starting and riding.

RES: This indicates Reserve. With the fuel cock lever in this position, he fuel reserve is made available. Quickly turn the fuel cock leveer to this position if you run out of fuel while riding, otherwise the engine may stall and will have to be primed (see PRI). After turning the fuel cock lever to RES, refuel as soon as possible and be sure to turn the fuel cock back to ON.

PRI: This indicates PRIME. With the fuel cock lever in this position, the engine can be Primed. Turn the fuel cock lever to this position when the engine has been allowed to run out of fuel. This sends fuel directly to the carburetor, which will make starting easier. After the engine has started, be sure to turn the lever to ON (or RES if you have not re-fuelled yet). 

For the life of me, I cannot remeber which is the OFF position, but if I ever left the tap in ON, the bike never started cleanly as I reckon fuel seeped into the crab while it wa stood. It was never a problem when I switched it OFF.

Experiment by taking the fuel pipe off at the cock outlet and switch the cock positions, to be OFF you need no fuel seeping out

Posted

I'm with Airhead, vacuum tap with no off position, if you have 2 pipes going to the tap from the tank then it's a vac if you have one pipe going to the tap from the tank then it's gravity fed.

Posted

Thanks.

Yeah looking at the manual there is no off position.
Took 20 minutes to get her started yesterday, the cold starts are a nightmare and that first 2 miles or so is like pulling teeth, and then she's happy as larry.
Riding from Gatwick to Brighton I was taken aback as I watched the speedo steadily rise through 50, 60, 70! and then hit 82!!!
Full tank weight of fuel on a stock xvs125, I actually shouted 'OH FUCK' inside my helmet when I glanced at the speedo.

Posted

Thanks.

Yeah looking at the manual there is no off position.
Took 20 minutes to get her started yesterday, the cold starts are a nightmare and that first 2 miles or so is like pulling teeth, and then she's happy as larry.
Riding from Gatwick to Brighton I was taken aback as I watched the speedo steadily rise through 50, 60, 70! and then hit 82!!!
Full tank weight of fuel on a stock xvs125, I actually shouted 'OH FUCK' inside my helmet when I glanced at the speedo.

Aye, but the manual also says "turn the fuel cock on" (from an off position)

Air filter clean? Plugs correct type and gap? Getting a good spark when you first fire it up? If it is a vac cock, isnt there a filter inside it?

  • 2 weeks later...
Posted (edited)

So after all that, it was water getting in the fuel. Haven't worked out how yet but had been getting frustrated with funding the Yamaha dealers christmas party so went elsewhere who said that was one of the first thing they should have checked.
Within 10 minutes I was also informed the 'new plugs' had not been changed and the carbs hadn't been properly done. Yamaha had charged me 5 hours labour for that the cheeky gobshites. 

On the plus side she now has a new MOT and runs lovely, just need a new brake disc now.

Edited by Dom1878
  • Like 1
Posted

Result Dom, about bloody time, hope your going to "HAVE WORDS" with the other bunch of wasters?

Posted

I will let them know their mechanic needs a word considering they are the UK's original Yamaha dealership.

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