Bike only fires when Button is Pressed

[Guest]

So around November I couldn't get my 850G to start. At first it was having trouble cranking, even with full battery. It also wouldn't bump start which I thought was odd. However since riding season was just about over anyways I put it away for the winter. Not having real access to a garage and keeping the bike in the school parking deck it made working on it difficult over winter.

Fast forward up to a few weeks ago, I finally diagnosed my cranking issue as a faulty starter motor. I got a new used one from a member here and the bike finally cranked again. It wants to start, and burbles to life as soon as I press the button, but it will not catch and keep running.

I'm thinking this may be due to dirty and un-synced carbs but I'm not sure.

For reference I replaced the O-rings, and boots last October as well as cleaned the air filter and re-sealed the air box. The valves are all within spec as well.

Am I thinking in the right direction that the problem now lies with the carbs? As soon as I touch the button it seems to turn over and fire but it will not STAY running. Any advice is much appreciated.

(I do have the barr o-ring kit and berryman's sitting at home but I've been hesitant to tear apart the carbs because they seem scary and I'm probably being stupid about it )

Thanks guys.

[JEEPRUSTY]

So around November I couldn't get my 850G to start. At first it was having trouble cranking, even with full battery. It also wouldn't bump start which I thought was odd. However since riding season was just about over anyways I put it away for the winter. Not having real access to a garage and keeping the bike in the school parking deck it made working on it difficult over winter.

Fast forward up to a few weeks ago, I finally diagnosed my cranking issue as a faulty starter motor. I got a new used one from a member here and the bike finally cranked again. It wants to start, and burbles to life as soon as I press the button, but it will not catch and keep running.

I'm thinking this may be due to dirty and un-synced carbs but I'm not sure.

For reference I replaced the O-rings, and boots last October as well as cleaned the air filter and re-sealed the air box. The valves are all within spec as well.

Am I thinking in the right direction that the problem now lies with the carbs? As soon as I touch the button it seems to turn over and fire but it will not STAY running. Any advice is much appreciated.

(I do have the barr o-ring kit and berryman's sitting at home but I've been hesitant to tear apart the carbs because they seem scary and I'm probably being stupid about it )

Thanks guys.

check a float bowl for gas.
is petcock set to prime?

[Dave8338]

Sounds like "old gas" to me.

Clean carbs won't hurt anything.

[chuck hahn]

Gas will evaporte over a winter..if he doesnt put it on prime for a few before cranking hes just sucking air...thats my first guess. Dry bowls.

[duaneage]

Dumb question for you but is the choke opening all four chokes on the carbs? You are applying full choke when you start it , right?

you have power to the coils when cranking so it's not electrical there,

you could look inside the carb throats and see if one of the slides is stuck in the up position. That would cause imbalance that would interfere with the choke circuit. Make sure that they are all resting on the bottom

[Tim Tom]

Yea I set it to prime before I tried to start it. I'll check one of the bowls to see that it really is getting fuel into it. I was also on full choke yes. I'll hopefully get some time tomorrow to look up into the carb throats and inspect the slides.

Thanks for the replies, I'll update on the situation as it unfolds.

[Larry D]

Dip them carbs !!! Get them sparkly clean !!!!!

Do it....Do it....Do it !!!!!

[Don-lo]

Sounds like it needs more prime, but be careful, as a sticking float will quickly overflow the carbs. When they start like this, I usually pump the forks up and down. This bounces the floats a little, in case they are hanging, and it sloshes the gas in the bowls, allowing more to be sucked up the venturi.

If it still won't start, put in new plugs.

[duaneage]

It's a lean problem. He might need to blow into the vent tubes

[Octain]

A bike that wont start would require new, NEW(did I say NEW) plugs before I did anything else. If still nothing, check the bowls for fuel.
There is really no such thing as "more prime". Prime is prime, period. Put the bike on prime till it starts and then put it on run.

Its also said that a hard starting bike might need the valve adjusted although I cant varify this. MIne were way out of adjustment and the bike started fine.

I say adjust the valves as it might need it anyway, and rebuild/clean the carbs.

[Octain]

Dip them carbs !!! Get them sparkly clean !!!!!

Do it....Do it....Do it !!!!!

People avoid this like the plague for some reason!

[cowboyup3371]

People avoid this like the plague for some reason!

I have to admit that taking them apart is a little nervewracking. Taking mine apart this week to paint them is the first time I've done it by myself. I'm pretty sure I'll get everything back together okay because of Basscliff's site and what I can remember from CdNoel doing it last year, but I'm still nervous about the bench synching and on the bike synch; especially since I don't have a carbtune tool.

Either way, like I'll do, it's necessary to just trust yourself and look for help if needed from the folks here.

[Don-lo]

lol, Octain, I think you will find out that prime will eventually bite you if don't try and turn it off as soon as you think the bowls are full. Floats can stick when the bowls are empty, and it quickly turns into an airbox full of gas or worse, hydrolock. I had hydrolock happen on an FJ1100 this way, while I was standing there, giving it an extra few seconds to ensure full bowls. I'm lucky there were no bent rods or valves. Running gas out the overflow or into the airbox happens enough that I recommend erring on the side of slightly underful, giving it about 10 seconds before returning to ON. This also avoids the occasional "left it on prime" problem.

So, for me, prime is 10 seconds, more prime is 15 seconds, more more prime is 20 seconds, and after that I start looking for other problems.

[Tim Tom]

Too much prime?

When I last tried to start the bike I left it on prime and tried the starter button. It was on prime easily for over a minute. There was a strong smell of gas and it could have easily flooded the carbs.

I will try again tonight as soon as I am out of my my night class and see what I can see. If still nothing then I will have to bite the bullet and pull the carbs for dipping.

[Octain]

lol, Octain, I think you will find out that prime will eventually bite you if don't try and turn it off as soon as you think the bowls are full. Floats can stick when the bowls are empty, and it quickly turns into an air box full of gas or worse, hydrolock. I had hydrolock happen on an FJ1100 this way, while I was standing there, giving it an extra few seconds to ensure full bowls. I'm lucky there were no bent rods or valves. Running gas out the overflow or into the airbox happens enough that I recommend erring on the side of slightly underful, giving it about 10 seconds before returning to ON. This also avoids the occasional "left it on prime" problem.

So, for me, prime is 10 seconds, more prime is 15 seconds, more more prime is 20 seconds, and after that I start looking for other problems.

Easy.. Walk up to the bike, turn the valve to prime and start the bike. As soon as the bike starts, turn it off prime. I dont think there is any position on the valve for "more prime".
Dude, prime is prime.
You can even run the bike on prime if ya want, just dont forget to shut it off before ya park the bike. Which is when it could get messy.
But the point is still, ya cant give it more prime as you said.