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Posted

hi, ive got a sachs roadster 125 (same engine as a virago), i ran out of fuel the other day, and ive just been and put a fiver in, gone to start the bike and it wont have it. Ive checked the plugs, HT leads, fuel is getting to the carb but i think thats as far as its going, the bike will start but it idles very low and eventually cuts out, even when i bump start the bike. Ive tried everything i can think off, just coming on here for some advice.

Thanks.

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Posted

Quick update,

Just cleaned carbs and all fuel lines, now the bike starts but it wont idle at all, i have to keep revs on or it will just cut out, also it doesnt sound right it sounds like its running rough.

Posted

Quick update,

Just cleaned carbs and all fuel lines, now the bike starts but it wont idle at all, i have to keep revs on or it will just cut out, also it doesnt sound right it sounds like its running rough.

what colour are ur spark plugs? is the choke on?

Posted

what colour are ur spark plugs? is the choke on?

No choke, and when i took the plugs out one was black and wet and the other was dry and light brown, the problem seems to have started after tightening my chain, confusing me now. ( oh and you were right about taking off the tank, piece of piss !)

Posted

could be the clutch is catching/dragging (well sounds like it) adjust the clutch cable to make it tighter, but not too much and get back to me, oh and check ur chain it tends to tighten up the 1st time you adjust it. ;)

(just incase your not sure how to adjust the clutch cable)

you have 1 adjuster at the lever end and another at the engine end

do the engine end one as it has more effect

if you get a couple of spanners (think 12mm ....not sure) undo the lock nut (little one) then undo the long nut (big one) by 4 full turns, start the bike and see if that helps then adjust accordingly and do back up.

adjust the biting point on the lever end adjuster.

and the sachs is one of the easiest bikes to work on lol.

Posted

oh forgot to ask ..... when you cleaned the carb, did you take the jets out and blow through them? there is only 2 jets that come out and they both have a flat head screwdriver bits on them....

the one in the middle with the wide stubby head is the main jet (works from 1/2 throttle to full throttle) and then there is the long thinner one which is the pilot jet.

the pilot jet sorts out starting and idling so could be blocked causing the bike to not run on idle and be rough.

  • Moderator
Posted

No choke, and when i took the plugs out one was black and wet and the other was dry and light brown, .........

No wonder its running rough...it's running on one ;)

Take out the wet plug, leave it a day to dry out and try again, if you have another plug try that,

Posted

oh forgot to ask ..... when you cleaned the carb, did you take the jets out and blow through them? there is only 2 jets that come out and they both have a flat head screwdriver bits on them....

the one in the middle with the wide stubby head is the main jet (works from 1/2 throttle to full throttle) and then there is the long thinner one which is the pilot jet.

the pilot jet sorts out starting and idling so could be blocked causing the bike to not run on idle and be rough.

I didnt take the jets out, ive just had a look on carb and the only flat head screws i can see are very small, on the right hand side of the carb, are these the jets? Im gonna try some new plugs tommorow.

Posted

ok when you said you cleaned the carb did you take it to pieces? the jets are inside the carb at the bottom.

but try cleaning the plugs and swapping them over 1st (so plug in rear cylinder goes at the front and visa versa) then see if that sorts it out.

Posted

ok when you said you cleaned the carb did you take it to pieces? the jets are inside the carb at the bottom.

but try cleaning the plugs and swapping them over 1st (so plug in rear cylinder goes at the front and visa versa) then see if that sorts it out.

Im gonna have another go tommorow, im gonna test for compression, switch the plugs, and i might actually open up the carb and give the jets a clean, can you give us a rough idea of how to do it, and how hard is it? Doesnt sound right to me how he bikes running, it will rev freely but when i let the revs off it seems slow to decrease them? doesnt sound healthy at all, hoping ive got compression on both cyclinders, if i have then ill be a happy man.

Posted

well clean and switch the plugs b4 u take the carb off.....never know, might just need new plugs.

as to checking the carb il do it in steps.and keep the carb on the bike.

1.take tank off

2.there is a little flat head screw that leads to an outlet on the left of the carb at the bottom, its the fuel drain screw. undo it and empty the carb of fuel. (dont turn the mix screw)

3.on the left there should be 4 (+ drive) screws around the "cover" undo them and take the cover off

4.right... there will be a float that goes up and down then some brass bits sticking out.

5.the one in the middle is the main jet, undo it and blow through it then put it back in (use a flat head screwdriver)

6.to either the left or right (cant quite remember) you will see another brass "pipe" thing with a flat head screwdriver bit on the top

7.undo it. It should be about an inch long with holes around the bottom, thats your pilot jet!

8.blow through it and put back in

9.put everything back together

10.let fuel in for a few seconds then try and start the bike.

this should get rid of any dirt stuck in the jets, its a little fiddly but try not to contaminate anything with dirt

if cleaning the carb and swapping the plugs dont help then we can go through what else to check.

good luck B)

Posted

well clean and switch the plugs b4 u take the carb off.....never know, might just need new plugs.

as to checking the carb il do it in steps.and keep the carb on the bike.

1.take tank off

2.there is a little flat head screw that leads to an outlet on the left of the carb at the bottom, its the fuel drain screw. undo it and empty the carb of fuel. (dont turn the mix screw)

3.on the left there should be 4 (+ drive) screws around the "cover" undo them and take the cover off

4.right... there will be a float that goes up and down then some brass bits sticking out.

5.the one in the middle is the main jet, undo it and blow through it then put it back in (use a flat head screwdriver)

6.to either the left or right (cant quite remember) you will see another brass "pipe" thing with a flat head screwdriver bit on the top

7.undo it. It should be about an inch long with holes around the bottom, thats your pilot jet!

8.blow through it and put back in

9.put everything back together

10.let fuel in for a few seconds then try and start the bike.

this should get rid of any dirt stuck in the jets, its a little fiddly but try not to contaminate anything with dirt

if cleaning the carb and swapping the plugs dont help then we can go through what else to check.

good luck B)

Right ill have a go tommorow, i havent had the time to mess about with it yet, so hoping to get things checked tommorow. Can i leave the carb on the bike with those instructions?

Posted

i think uv just found the problem m8......if its split then it will be letting air in, making the engine run rough.

its a common fault but needs sorting.

  • Moderator
Posted

Ive fixed bike now, it was the inlet pipe that were causing the problems. Bike runs fine now and idles great, off to get some spark plugs soon, shall i get iridiums or standard ones?

Thanks for your help lads :D

Posted

Ive fixed bike now, it was the inlet pipe that were causing the problems. Bike runs fine now and idles great, off to get some spark plugs soon, shall i get iridiums or standard ones?

Thanks for your help lads :D

( just noticed a small leak under the exhaust, it seems to be coming out of a small hole underneath the exhaust, smells like water is it just condensation?)

Posted

( just noticed a small leak under the exhaust, it seems to be coming out of a small hole underneath the exhaust, smells like water is it just condensation?)

Standard plugs

If the hole looks like its round ie put there deliberately, then its a drain hole

  • Moderator
Posted

( just noticed a small leak under the exhaust, it seems to be coming out of a small hole underneath the exhaust, smells like water is it just condensation?)

:rolleyes::lol:

Posted

:rolleyes::lol:

:lol: Well it doesnt smell like petrol or oil so it smells like water :lol::D

. :(

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