25,4 cc gas engine carb does not keep settings
04-01-2019, 12:47 PM
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25,4 cc gas engine carb does not keep settings
hello from germany ! i have a reely carbon fighter3 buggy 4wd 1:6 . it has a 4 bolt 26cc engine which appears to be very similar to the 26cc fuelie engine . .
after setting the carb for good performance and a trouble free run the car seems to be way to rich next day with the same fuel and carb settings . screwing the needles in it jumps very quickly into the lesn side with only a very slim adjustment range . the carb appears to be a chinese copy of a walbro 668 .
with a tachmeter i get 12300 rpm with wheels in air .
any idea where to look ?
best regards
after setting the carb for good performance and a trouble free run the car seems to be way to rich next day with the same fuel and carb settings . screwing the needles in it jumps very quickly into the lesn side with only a very slim adjustment range . the carb appears to be a chinese copy of a walbro 668 .
with a tachmeter i get 12300 rpm with wheels in air .
any idea where to look ?
best regards
04-02-2019, 12:33 PM
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i have put apart the carb and will give it a bath in ultrasonic as well a blow out with compressed air . the diaphgram is nice but the gasket junk . can the diaohgram be insralled between the primer bulb and carb without the gasket to serve by itself as a gasket ?
parts are only cents but hard to get
parts are only cents but hard to get
04-03-2019, 07:57 AM
#4
You need the gasket because that gives the clearance needed for the pump diaphragm to move.
Mothers is a screen on the regulator side that needs to be squeaky clean. If you can carefully remove it, clean it, and reinstall it, you’re okay. 90% of the time that screen is the problem with a walbro type carburetors. Otherwise the carb is just dirty or the diaphragm isn’t good anymore.
Mothers is a screen on the regulator side that needs to be squeaky clean. If you can carefully remove it, clean it, and reinstall it, you’re okay. 90% of the time that screen is the problem with a walbro type carburetors. Otherwise the carb is just dirty or the diaphragm isn’t good anymore.
04-03-2019, 11:48 AM
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thanks for clarification !
i now bought an original walbro gasket kit for a leaf blower at my local garden equipment store and will reinstall it tomorrow ! i will report and check the screen.
funny to say any gasket part for a 25.4 cc zenoah / walbro in a leaf blower fits perfectly in this 25,4 cc chinese rc car engine and chinese carb . its a 1:1 copy , but hard to say if the entire engine is a copy of a zenoah or chung yang .
i now bought an original walbro gasket kit for a leaf blower at my local garden equipment store and will reinstall it tomorrow ! i will report and check the screen.
funny to say any gasket part for a 25.4 cc zenoah / walbro in a leaf blower fits perfectly in this 25,4 cc chinese rc car engine and chinese carb . its a 1:1 copy , but hard to say if the entire engine is a copy of a zenoah or chung yang .
04-13-2019, 04:44 AM
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ok i still have issues ... the carb ia fully rebuild with original walbro gaskets and i put a new ngk plug in to exclude the chinese torch plug .
the car starts good cold but when tuned for decent performance ( i have installed a tachmeter which measures actual rpm and records peak rpm , i reach 12300-12500 with wheels in air and 9500 with car running ) the engine tends to stall after few laps , especially when you return from WOT to idle and is very hard to restart . often only posdible when you let it cool down a bit.
by 'feel' the compression had not worsen since new and looks good , no scoring in the piston.
any ideas ?
the car starts good cold but when tuned for decent performance ( i have installed a tachmeter which measures actual rpm and records peak rpm , i reach 12300-12500 with wheels in air and 9500 with car running ) the engine tends to stall after few laps , especially when you return from WOT to idle and is very hard to restart . often only posdible when you let it cool down a bit.
by 'feel' the compression had not worsen since new and looks good , no scoring in the piston.
any ideas ?
