This forum uses cookies
This forum makes use of cookies to store your login information if you are registered, and your last visit if you are not. Cookies are small text documents stored on your computer; the cookies set by this forum can only be used on this website and pose no security risk. Cookies on this forum also track the specific topics you have read and when you last read them. Please confirm whether you accept or reject these cookies being set.

A cookie will be stored in your browser regardless of choice to prevent you being asked this question again. You will be able to change your cookie settings at any time using the link in the footer.


Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Engine query
#1
Hopefully someone can help.

MrsSponge has a broken 4 stroke scooter that we are trying to repair to sell. Amongst other things it wont start. With a charged battery it will turn over but doesnt fire. I suspect it needs a new spark plug which I have but just not fitted. However, when it cranks it makes a chuffing/puffing sound as well, which doesnt sound normal (its quite loud). Any ideas what would cause that? The exhaust is a bit ratty and pretty rusty but no holes that I can see

Any ideas?
2010 Canyon Aeroad 9.0 SL
2014 Specialized Epic Marathon
Reply
#2
"treaclesponge" Wrote:Hopefully someone can help.

MrsSponge has a broken 4 stroke scooter that we are trying to repair to sell. Amongst other things it wont start. With a charged battery it will turn over but doesnt fire. I suspect it needs a new spark plug which I have but just not fitted. However, when it cranks it makes a chuffing/puffing sound as well, which doesnt sound normal (its quite loud). Any ideas what would cause that? The exhaust is a bit ratty and pretty rusty but no holes that I can see

Any ideas?

Puffing Chuffing with or without spark plug in
Reply
#3
With the spark in place
2010 Canyon Aeroad 9.0 SL
2014 Specialized Epic Marathon
Reply
#4
Stuck valve.
Reply
#5
Could it be a chuffing/popping sound?

Could be that's there's fuel & no spark.  Small engines take ages to build up to a proper back fire, but unsed fuel will combust in the exhaust as it mixes with air.
Fit your new plug & see what difference it makes.

There are ways to check, but I'm not going to explain them here as they can be dangerous :o
Reply
#6
I was wondering if a good squirt of easy start or a splash of fuel in the air intake may help things move along...
2010 Canyon Aeroad 9.0 SL
2014 Specialized Epic Marathon
Reply
#7
Remember your physics lessons
Heat+Fuel+Oxygen = combustion

If there's no spark you can put neat rocket fuel in there, it'll still pop & bang in the exhaust on the way out.
Easy start is great & does make it easy to start an engine, but it's a fuel replacement, not a spark replacement.

You could of course use the easy start to prove it's electric rather than fuel presenting the problem.
If it fires with easy start in the intake & runs for a few seconds & then stops it's probably fuel.
If the easy start makes little difference then it's electrics.
Reply
#8
I'm skeptical that the current plug is broken but for £3 couldn't justify not changing it so I'll try and see what happens. Been using jump leads from the car to the battery to rule out a charge issue. I'll have another go soon and report back.
2010 Canyon Aeroad 9.0 SL
2014 Specialized Epic Marathon
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)