Noob with HT Not Happy

SchwinnHS

New Member
Joined
Jun 18, 2008
Messages
10
I installed a HT on my Schwinn Mountain bike and was riding and having fun for a couple weeks but started having problems getting the thing started. I have verified I have spark, fuel (with air), and compression. I also use the 20:1 ratio mixture with premium gas. I had some backfiring after about a 35 minute ride and thats when my problems started. Could this have damaged the carb. The fuel bowl looks ok but I can smell gas in the cyl and plug. Seems like it's flooding quickly. Anyone out there experience this?
 

Alan

Member
Joined
Feb 26, 2008
Messages
226
Plug isn't fouled ? Have you tried regular grade fuel ?
Getting back to the plug, they are manure, and can fail. Try a new NGK.
Air filter OK?
Screw approx 4 turns out ?
Working, clean, in-line fuel filter ?
 
Last edited:
S

Simonator

Guest
Well, first off, Premium gas is an overkill. You are just wasting your money. 85 - 87 octane is plenty for our low compression engines. Have you adjusted the carb at all? What is your spark plug gap? I don't think a little backfiring is going to hurt the carb. Also make sure there is no vacuum leaks in your intake. Let your engine completely warm up, then use the choke to see if it stalls. It should stall right away. If not, you have a vacuum leak somewhere.
 

bluegoatwoods

Well-Known Member
Joined
Mar 23, 2008
Messages
3,019
I'm no expert, so I can't offer much. But you mentioned that you have fuel, air and spark.

That should mean a running engine. If not, then I would suspect that your spark is intermittent. That's where I'd be looking.

Good luck.
 

SchwinnHS

New Member
Joined
Jun 18, 2008
Messages
10
Yea its the weirdest thing. I think I have removed the carb from being the problem. I verified spark with a new plug gapped at .034. Just grounded it against side of motor and cranked. I'm getting a nice little blue spark. I sprayed some engine starter directly into the cyl and screwed the plug and cranked away. I figure i should atleast get a pop or something. Nothing. Could i have wrecked the timing somehow? Getting ready to take the thing aprt and start over.

Oh and thank you all! I finally found this place after thinking I was all alone out here. Its nice to be part of the group. This site has everything you need to know to get motorized!

Dave - Albuquerque
 
H

HoughMade

Guest
Do these things have a key on the output shaft? If so, it could have sheared with the backfire. I know engines, but I don't have a HT.
 
Joined
Mar 16, 2008
Messages
688
Yea its the weirdest thing. I think I have removed the carb from being the problem. I verified spark with a new plug gapped at .034. Just grounded it against side of motor and cranked. I'm getting a nice little blue spark. I sprayed some engine starter directly into the cyl and screwed the plug and cranked away. I figure i should atleast get a pop or something. Nothing. Could i have wrecked the timing somehow? Getting ready to take the thing aprt and start over.

Oh and thank you all! I finally found this place after thinking I was all alone out here. Its nice to be part of the group. This site has everything you need to know to get motorized!

Dave - Albuquerque

Spark apparently isnt your problem but .034 is too wide a gap for the spark plug. I would gap somewhere between .020 to .025 There is a key on the magneto and if it sheared and moved partially that would change timing, therefore the backfire...
 
Last edited:

SchwinnHS

New Member
Joined
Jun 18, 2008
Messages
10
I really don't know enough about the motor to answer that. It looks like there isn't a key from what i can see without opening the crank case.
 

SchwinnHS

New Member
Joined
Jun 18, 2008
Messages
10
Yea, There is a tiny key on the magneto side of the output shaft. It's still in place so my timing should be ok hopefully.
 

SchwinnHS

New Member
Joined
Jun 18, 2008
Messages
10
Those darn spookytooth instructions say to gap at .038 I will get another plug and try .020 to .025. I'd rather be riding! Thanks again
 
Top