89 exciter 570 popping!?!?

smkin_exciter_420

New member
Joined
Jan 25, 2012
Messages
50
Age
33
Location
spokane wa
hey i have an 89 exciter w/ electric start and i had it running damn good. i was ripping down my road at 100mph...wow.... then i parked it and started it 5 hrs. later and it started popping and backfiring out of the right side cylinder..... bit wouldnt rap out and it did clear up but not the same .... it wont even reach top rpm:( it is bored .20 over, twin psi pipes, pod filters with extended 90 degree tubes so the airfilter is outside the hood. i mix my gas richer than rich... do all the carb vent tubes need to have hoses on them? i broke the plastic nossle off so i just left it.
 

cylinders both checked out... i might be getting air leak from crank seal or rubber intake boot. cause its running a little lean.. do you think it could be the carb? they sat all summer long. i fixed the popping now just a little lean...why would i have to run a 320 and 340 on the other? i thought they were suppose to be identical,,,hhhmmmm ill try for air leaks in the morning and if no fix... tear down the carbs... :2strokes:
 
What spec / number would "cyl checked out" be?

320 sounds lean for how your pulling air to the carbs + twin pipes. Sounds like it's hurt to me. Pull both pipes off and look up the cyl at the exhaust side of the pistons and see what they look like
 
toydoc said:
What spec / number would "cyl checked out" be?

320 sounds lean for how your pulling air to the carbs + twin pipes. Sounds like it's hurt to me. Pull both pipes off and look up the cyl at the exhaust side of the pistons and see what they look like

Sounds hurt to me too.
 
ill be pissed if its hurt ive had the pto side piston melt on me and actually i have a couple other cylinders and pistons...if you want to hear something crazy..i bought a set of oem rings ,020 over went to install them and realized i had a stock .020 over piston... by stock i mean yamaha...and a wiseco pro-lite piston.5mm over and well we all know wiseco and oem shit dont fit together like a puzzle should...so i started cutting my puzzle pieces to fit...ha ya you are all like this kids an idiot..i had to use a dremel to trim the upper and lower edges of the ring groove for them to fit. also the ring end gap on pro-lite squeeze over a vertical pin instead of oem horizontal ...SERIOUSLY and that cylinder gets 141psi the right hand cylinder gets 134psi those #'s are close enough right? i dont think they are getting broke in though because i have the thermostat held open with a screw(previous owner) and u can always touch your hand straight to the cylinder head right after you kill it after running it for even 20min..and i hope my sled isnt hurt because i refuse to pay 40$ for a headgasket... i tore the metal out of the ones that were used ind rtv the shit out of it ...pain in the *** i know but what is someone who is broke like me gonna do right
 
toydoc said:
What spec / number would "cyl checked out" be?

320 sounds lean for how your pulling air to the carbs + twin pipes. Sounds like it's hurt to me. Pull both pipes off and look up the cyl at the exhaust side of the pistons and see what they look like

well the cylinders are port and polished and the 90 degree things for my make shit cool air kinda restrict it a little and im running q6 nossels im not 100% on the neddles q6 might be in that # as well im not for sure ..147.5 pilots and 320 mains...this is a high elevation sled too. the damn cluch dosent engage till 4350-4550rpm extended to 138" 2 " paddles. its rapping out fine now just need to figure why its lean... just through some new br9ecs in her ...funny thing i never new those plugs exsisted... then i started seeing them all over snowmobile talkk..
 
If it does'nt have it already, you need the 90 Exciter needles (PSI copies). I think the twin pipes need Q8 nozzels (but that may be for ported motors only). I'm sure I've seen this info either on this site or the FB Exciter page. Do a search.

I could be wrong, so make sure you do some research.

Good Luck, John
 


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