125 stroker backfiring at top end.
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125 stroker backfiring at top end.
any clues or suggestions would be greatly appreciated, thnx
- kingkamehameha
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Re: 125 stroker backfiring at top end.
Must be the signal fluid
ua mau ke 'ea o ka aina i ka pono o hawaii
Re: 125 stroker backfiring at top end.
I have never seen a WOT backfire NOT caused by being lean. To rich just makes the motor go flat.
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- paulpauly7
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Re: 125 stroker backfiring at top end.
Possibly 4 strokeing at max rpm
86 Nifty Fifty (spree)
ZX disk brake
Kitico 120kmh speedo
AF18 ZX ported
Polini corsa
Malossi crank
CTmani
24mmOKO
40pilot118main
Scorpion pipe
8.44 to 1
Michelin s1
71.3mph
92 yz125, 94 crm250
ZX disk brake
Kitico 120kmh speedo
AF18 ZX ported
Polini corsa
Malossi crank
CTmani
24mmOKO
40pilot118main
Scorpion pipe
8.44 to 1
Michelin s1
71.3mph
92 yz125, 94 crm250
Re: 125 stroker backfiring at top end.
What is the motor doing when it back fires? What does the temp gauge say? What does the plug look like? How fast are you going when its doing it? Are you at wot or closed throttle,partial throttle?
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- Dio89Elite
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Re: 125 stroker backfiring at top end.
need more info, so that we can help with diagnosis.
I was thinking the same questions as bakaracer.
imo it's running lean. are you running any filter? what premix ratio are you running?
good way to find out is plug chops (what does the plug look like?)
I was thinking the same questions as bakaracer.
imo it's running lean. are you running any filter? what premix ratio are you running?
good way to find out is plug chops (what does the plug look like?)
Re: 125 stroker backfiring at top end.
bike starts to sputter @ almost wot then backfires doing @ 60mph and temp @ 375. dont think im running lean wit a 175 main unless my carb is goin empty. was wonderin if it could be my petcock. also using a 62 pilot and uni filter.
Re: 125 stroker backfiring at top end.
What kind of bike is this motor on? It could either be a leak somewhere or running out of gas. But more likely a leak due to the size jets your using.arnada wrote:bike starts to sputter @ almost wot then backfires doing @ 60mph and temp @ 375. dont think im running lean wit a 175 main unless my carb is goin empty. was wonderin if it could be my petcock. also using a 62 pilot and uni filter.
Nothing like getting stroked!
Thanks to my sponsors
Nos Energy Drinks,themopedcompany.com,nwautoevents.com,Cycle Gear
90 honda dio sp 72cc
87 elite 50 s with 86cc watercooled mini stroke
87 elite 50 race bike mhr 72cc
91 yamaha tzr 250r
Thanks to my sponsors
Nos Energy Drinks,themopedcompany.com,nwautoevents.com,Cycle Gear
90 honda dio sp 72cc
87 elite 50 s with 86cc watercooled mini stroke
87 elite 50 race bike mhr 72cc
91 yamaha tzr 250r
Re: 125 stroker backfiring at top end.
wassup baka
you think a crankcase leak would do this or would it have to be an intake leak? been workin 12 hour shifts n mondays my next day off. itll be then that ill be able to look things over. ill probly take my intake apart first n check my reeds and put some sealant on the gaskets then test run. also check vacuum line and petcock. already changed carbs and last thing id wanna do is split the block and reseal with honda bond. peace!
you think a crankcase leak would do this or would it have to be an intake leak? been workin 12 hour shifts n mondays my next day off. itll be then that ill be able to look things over. ill probly take my intake apart first n check my reeds and put some sealant on the gaskets then test run. also check vacuum line and petcock. already changed carbs and last thing id wanna do is split the block and reseal with honda bond. peace!
- kingkamehameha
- CB900F
- Posts: 1215
- Joined: Sat Apr 16, 2011 1:11 pm
- Location: kailua kona
Re: 125 stroker backfiring at top end.
Before you rip everything apart pressure test the motor
ua mau ke 'ea o ka aina i ka pono o hawaii
Re: 125 stroker backfiring at top end.
it could be a leak in the case. you need to check everything that leads into the case if you dont have a pressure tester. so crank seals, oil plug,case halves,gaskets,spark plug even check the carb spigot. make sure the fuel and vacuum hoses are tight.if air can seep between the nipple and hose, it can lean out too.arnada wrote:wassup baka
you think a crankcase leak would do this or would it have to be an intake leak? been workin 12 hour shifts n mondays my next day off. itll be then that ill be able to look things over. ill probly take my intake apart first n check my reeds and put some sealant on the gaskets then test run. also check vacuum line and petcock. already changed carbs and last thing id wanna do is split the block and reseal with honda bond. peace!
Nothing like getting stroked!
Thanks to my sponsors
Nos Energy Drinks,themopedcompany.com,nwautoevents.com,Cycle Gear
90 honda dio sp 72cc
87 elite 50 s with 86cc watercooled mini stroke
87 elite 50 race bike mhr 72cc
91 yamaha tzr 250r
Thanks to my sponsors
Nos Energy Drinks,themopedcompany.com,nwautoevents.com,Cycle Gear
90 honda dio sp 72cc
87 elite 50 s with 86cc watercooled mini stroke
87 elite 50 race bike mhr 72cc
91 yamaha tzr 250r
Re: 125 stroker backfiring at top end.
Off Topic....
What is 4 stroking?paulpauly7 wrote:Possibly 4 strokeing at max rpm
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01 Elite 50SR
'85 Spree
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Re: 125 stroker backfiring at top end.
When the fuel mixture is so far off that the engine only fires on every other stroke.CNI Dawg wrote:Off Topic....
What is 4 stroking?paulpauly7 wrote:Possibly 4 strokeing at max rpm
Bear 45/70
'83 Aero 80 X 3
'84 Aero 80 X 3
'85 Aero 80
'84 Aero 125 X 2
'84 Aero 125
'84 Aero 125 X 2
'85 Aero 50
'85 Spree
'83 Aero 80 X 3
'84 Aero 80 X 3
'85 Aero 80
'84 Aero 125 X 2
'84 Aero 125
'84 Aero 125 X 2
'85 Aero 50
'85 Spree
Re: 125 stroker backfiring at top end.
thanks
61Aand Still Having Fun !
Keeping the Dream Alive !
01 Elite 50SR
'85 Spree
CMRA #77 MCE, '03 CBR600RR - Dark Horse Racing
Keeping the Dream Alive !
01 Elite 50SR
'85 Spree
CMRA #77 MCE, '03 CBR600RR - Dark Horse Racing
Re: 125 stroker backfiring at top end.
switched out the 28 carb with a 30 and used a 58 and 165 jets today and ran pretty good, guess my jets mustve been too big
thanks a lot guys with all the inputs!
thanks a lot guys with all the inputs!