knocking problems

[missionadi000]

i have a carbrated 223single cyl .giving out 17bhp. it called a hero honda karizma and is available in india.

 

lately when i wend on the highway and was coming back into the city i noticed after the engine got a lil heated up and there was some noticeable loss in poer which is common is air cooled engines. bt was was bothering me was at lo rps i could hear lod knocking noise from the engine at even 2 gear as low as 2500 rpm. genreally in second knocking happenns when the rpm is around 1200 or so.

 

what could be the issue.

[missionadi000]

no help??

i really wanna know whats wron here cos the same thing is also affecting my milage

[bigboystoys]

Does the knock happen all the time or only recently?

 

If it happens all the time, then use higher octane fuel.

 

If it only happen recently, check your carbs. It is not metering enough fuel causing it to lean out and producing more heat than usual. This heat that is not dissipate properly causes the knocks which causes more unwanted heat and vibration which in turn cause more knocks. Vicious cycle.

 

 

[missionadi000]

cool thanks.

i think i must check the carb.

 

oh and by the way what would happenif i use higher octane fuel than needed. and can i mix high octane fuel with a lil left overs of older low octane fuel.

[bigboystoys]

Yea you could.

It'll just average out (lower slightly) the octane number.