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Old 01-01-2014, 11:09 PM
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mapbike mapbike is offline
Motorized Bicycle Elite Member
Join Date: Mar 2010
Location: Central Texas
Posts: 5,379
Default Re: what did you do to your motorized bicycle today?

Originally Posted by rogergendron1 View Post
i do this to all my motors !

well about that loss of power and 1/2 throttle bog.... well i drained all the gas and reamed out the main jet to a .74mm and made shure there was no air leaks, then added high oct fuel mixed 50:1 and fired it up and the same problem ! didnt fix it !

just for kiks i swapped back to my old brigs filter and baaaam !!!! bike runs beautiful and will rev till it blows ! speeds up to 40mph !!!

what the heck ? is the sbp 90 deg filter restrictiing air flow and bogging my motor ?
or is it flowing too much air and making me run lean causing the bogging ??

ether way when i put that sbp filter on it bogs down like someone cut off the fuel air once i pass half throtttle !
put the old oversized brigs filter on and wow !!! it ripps now with the new .74mm jet size !!! even more power than before !!!!!

whats up here ? i thought this was supposed to be a performance filter yet my retro fitted brigs and straton air filter makes runs perfect and the sbp filter kills the performance ?

this bugs me as i have been around the block trying to find the problem here

checking for air leaks, rebuilding the carb, rejetting, draining gass, checking fuel flow, cleanning carb out, exe.... only to find out after a quick swap back to my old filter, its the new sbp filter itself thats causing the bogging issue !!!!
There is a very simple way to tell if the sbp filter is causing a lean condition or a rich condition on your engine...... just run it down the road with no filter at all and if it bogs then you know you still need to go up on the main jet, if it runs great then you know the briggs filter is flowing more air to engine, the cloth filters flow better than a paper filter and for them to actually filter the dirt and dust out they need to be sprayed with filter oil.

I dont always ride WOT, but when I do..I do my best to keep the rubber side down..Ride safely my friends!
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