Bravo won't fire!!!

N

nosnownogo!

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Jan 26, 2004
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Lots of spark, lots of fuel and 120 compression......Should start right? Worng, she just won't go or even try..I'm down to ignition and timming. Is there a key in there that could become split and throw the timming off so bad that it woulden't even try??? Or am I missing something eles?
Thanks guys.
 
How do you know its getting fuel? Is it fresh gas? Try a touch of starting fluid to see if it fires then.
 
The bravo i had always started up, clean the carbs and see what happens.... The Bravo ran good till the oil line decided not to send oil to the motor seizing it up.... 215lbs guy on a 250cc sled in deep powder=bad. that was long ago.
 
I would put some gas in the cylinder and see if she fires.. my 85 has been through my to sons and still runs like a champ.
 
bypass the tors as described in the tec pages (if equipped). use a new plug and pour some gas down the cylinder. crank it over and see if it fires up. use fresh gas. if it still does not run, it is time to check coil resistances.
 
when you say "lots of fuel", what does that mean? is the plug soak and wet when you take it out?
 
Yes it is soaked.. Could the crankcase be full of gas, enough that the sled will never start? It has always run like a top. Never seen this before. The gas is fresh, the sled ran for 2 hours the night before. Lots of spark too!!
 
No-start

Had an old 338 that did that once. Seems a squirl or mice stored peanuts in the exhaust over the summer. The sled ran then died and refused to run. When we pulled the exhaust off, the motor would fire. That pipe had over a pound of peanuts and acorns in it. Just a glimmer from the past !
 
might have a weird one. i have had a split fuel pump diapram fill a bottom end full of gas through the pulse line. have also had a pulse line mess with me when it split on the bottom so it looked good untill i touched it.
 
Fuel pump seems to be working, pulse line is in tack too. Looks like a ignition problem to me. I pulled the motor and drained the crankcase, there was some gas in there but not alot. Is there some way the timming could have shifted and is now firing on a different stroke?? I think I'll totally drain the tank and carb tonight and fill with fresh gas again just in case.
 
Did you try a little starting fluid yet to see if it would fire? Spray a little in the spark plug hole, tighten the plug with your fingers and see if she fires. If so, Then you know its the carbs/fuel delivery. I dont think its timing. Is your spark consistent?
 
I just pulled the pulse line off and pulled with the plug out a million times to clean out any fuel that might be in there. New plug, checked spark (good) sprayed fuel right in cylinder replaced plug.... Still no go! WTF! These things are so simple it's stupid.. I feel like an idiot. I must be missing something. Is there any way the CDI can be firing late???
 
Anything is possible, How much fuel did you spray in?? I use the ether because it wont foul out so easy if you put to much gas/oil in.
Maybe your connections are backwards. Check your harness,
 
Would anyone have a schematic for a bravo, The connections are straight forward and ok. Tonight I will check all connections and maybe swap out the CDI.
 
Those bullet type connections can be swapped easy, I would check those.
If you have a extra CDI box give it a try.
 
sure sounds like to me the crankcase is full of gas and flooded, when you pull the sparkplug out and its soak and wet without putting fuel in the cylinder, its flooded. They will not start with a flooded crankcase. Alot of times the crankcase can also flood the pipe, same thing it wont start with a flooded pipe either. I would simply remove the pipe, and then use compressed air into the engine to remove excess fuel. You can also remove sparkplug, remove pipe and pull it over about 200 times and youll see the fuel coming out, get it cleaned out and I will guess itll start right up.

EDIT: I see you pulled the engine and drained the crankcase this morning, is the pipe full of fuel? (when i say flooded case and flooded pipe its not a gallon that will come out but if you have a paintcap full it will be enough to make it rich enough it will not fire the plug)
You might have a leaky needle and seat allowing excess fuel into engine. I highly doubt the cdi is the problem, If I am reading these post right, the sled ran the night before with no problems and then would not start the next day, was it placed up on a jackstand or anything overnight?

I have a spare coil, cdi box if you want to test if you think its electrical. Most of the time, if it shows good bright blue spark when you pull it over its not gonna be electrical that keeps it from starting up.
 
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There was some fuel in the exhaust, but not much, maybe a mouthfull..
Got about the same from the case too. I disconneced the the reg. thinking it may be draging the supply down, but still no go. Went to change the cdi but the spare I have looks the same but has more wires on it and will not work at all. Thinking now's time to check coil values, would anyone have the schematic for this beast, it's an 87. Thanks for all the ideas guy's...
 
so you have now removed the fuel from the case and the pipe, have you retried to start it? I would try to start it with the fuel line pinched and see if it tries to start. This will keep you from flooding it out again. if it wont then you have a problem else where.

is the spark bright blue??
 
After I cleaned the fuel out and reinstalled the motor, I left the pulse line off the pump so it would not get any more fuel. I pulled and pulled and pulled then squirted fresh fuel in the carb and it still diden't even try. The spark is a perfect snappy blue and it's there all the time. This is really driving me nuts... Looks like I will be pulling the tank, carb and fuel pump and draining all the fuel. I will blow out the case and start over again with fresh gas. How much fuel pressure should I have?
 
most likely not the fuel, if it ran the night before on it.

if you hook the pulse line back up so you dont have a vaccum leak and then take a small rag and pinch off the fuel line with pliers or vise grips. If you pull the sled over with no throttle it doesnt backfire, or pull back???, by pull back it tries to pull the rope handle out of your hand when your starting it.-this is what a cdi will do if its changing the timing,advancing it will pull back, if retarding it, will backfire.

new spark plug after the flooding?

have you checked the resistance of the sparkplug cap? they should be 5k ohms.
 
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