ScootDawg Scooter Forum - backfiring in the cold?

« backfiring in the cold? »

Welcome Guest. Please Login or Register.
May 21, 2013, 7:21pm

ScootDawg Scooter Forum :: The Garage :: 2 Stroke Scooters :: backfiring in the cold?

Author

Topic: backfiring in the cold? (Read 582 times)

voodoosix
Great Big Guru Dawg

member is offline

[avatar]

I commute by scoot, EVERYDAY!

Joined: Jul 2007
Gender: Male

Posts: 749
Location: Buena Vista Va

backfiring in the cold?
« Thread Started on Feb 28, 2008, 5:38am »

my scoot has started stumbling and backfiring under acceleration, it only seems to do it when its really cold out (30 degrees and below) and only till its been run through its rpm band once. runs fine after its been up to speed.

i wont get a chance to look at it till the weekend, any ideas on what to look for?

Link to Post - Back to Top IP:

Logged

Scootin' since '86
'08 Tomos Nitro 150
'01 Malaguti Phantom "Foggy" #301

wireburn
Great Big Dawg

member is offline

Hot Rod!

Joined: Sept 2006
Gender: Male

Posts: 198
Location: Muskegon, Michigan, USA

Re: backfiring in the cold?
« Reply #1 on Feb 28, 2008, 10:03am »

Probably just running lean in the cold. The problem would be worse at startup. I would just warm it up better before you ride it hard. For more peace of mind you can upjet the carb for the cold weather.

-Mike

Link to Post - Back to Top IP:

Logged

2006 Yamati Strada RX8 - NOW 103cc!

earlwb
Global Moderator

member is offline

[avatar]

Roketa Fiji 150

Joined: Jan 2007
Gender: Male

Posts: 8,657
Location: Grapevine Texas

Re: backfiring in the cold?
« Reply #2 on Feb 28, 2008, 5:34pm »

Nowadays they run the engines on the lean side. So in the fall you upjet a little and in the spring you go back to a little smaller jet.
it sucks but that seems to be the trend at present.
When the temperatures are cold outside the denser air makes the engine run a little more lean. Then when it is hot outside the air is less dense and the engine tends to run a little more rich. You can also do like they used to do and run a main jet that lets the engine run a little richer in the winter and not bother with it in the summer and just let is be on the rich side.

Link to Post - Back to Top IP:

Logged

2007 Roketa Fiji 150
2007 Roketa MC54-250B
1992 Harley Sportster 1200
-----------------------------------
"Life is not a journey to the grave with the intention of arriving safely
in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up,
totally worn out, and loudly proclaiming -- WOW--What a ride!!!"

voodoosix
Great Big Guru Dawg

member is offline

[avatar]

I commute by scoot, EVERYDAY!

Joined: Jul 2007
Gender: Male

Posts: 749
Location: Buena Vista Va

Re: backfiring in the cold?
« Reply #3 on Mar 7, 2008, 5:13pm »

this prob is now solved......

while lean jetting can lead to my symptoms, i didnt think that was the case here since this is my 7th winter on this bike and its the 1st time its happened.

the prob was the spark plug, even though its was only a month old and looked perfect- it was faulty. i had a new one on hand and swapped it in ..just in case.

sure enough, it started immediately and now runs like its old self.

Link to Post - Back to Top IP:

Logged

Scootin' since '86
'08 Tomos Nitro 150
'01 Malaguti Phantom "Foggy" #301

Click Here To Make This Board Ad-Free