Cold starting
#43
12-05-2006, 03:57 AM
RE: Cold starting
ORIGINAL: bryantjt
Must be that time of year......holidays, gotta love em and the stress they bring.
Must be that time of year......holidays, gotta love em and the stress they bring.
As far as hard starting is concerned...... I don't know, coldest morning so far this year was in the 50s here in S FL, no problems. lol
#44
12-05-2006, 04:09 AM
RE: Cold starting
Now THATS a 'cold start' mechanism that works EVERY TIME!!!
Got to love the holidays!!!!
Got to love the holidays!!!!
#45
12-05-2006, 04:31 AM
Join Date: Nov 2005
Location: Washington
Posts: 21,060
RE: Cold starting
So I get home after work around 5 and its around 40-43 somewhere in that range, and I go to start my bike, and it fires right up. There must be a threshold that makes it hard to start, probably somewhere between 35 and below.
#47
12-05-2006, 04:48 AM
RE: Cold starting
It's 31 here right now and mine cranked right up after holding the throttle open for a few seconds to give a little squirt of fuel (pumper carb). I hate to admit it, but mine has also sat for a while. I haven't started mine since sometime last week - just too covered up with work and getting dark early and family here over the weekend I haven't had a chance to get out.
But that's with the pumper carb which does actually squirt in fuel when you work the throttle even when the bike is not running. But it doesn't have a choke, and at least at 31 degrees it doesn't appear to need one. Jerry told me it would be OK with out it - now I believe him.
But that's with the pumper carb which does actually squirt in fuel when you work the throttle even when the bike is not running. But it doesn't have a choke, and at least at 31 degrees it doesn't appear to need one. Jerry told me it would be OK with out it - now I believe him.
#48
12-05-2006, 04:52 AM
RE: Cold starting
seems logical to me Nobrakes, since it seems to operate much the same way a primer button does on the "winter engines" I read about. Looks like thats the best of all worlds!!
(and the throttle wheelies dont suck either looks like!!
)
(and the throttle wheelies dont suck either looks like!!
)
#50
12-05-2006, 04:46 PM
RE: Cold starting
Deric
Short version.
Make sure you’re keeping the throttle closed when you crank the bike. Don’t touch it. Choke full on before cranking. Once you open the throttle, you lose air velocity through the carb, reducing the vacuum to the float bowl. Less vacuum, less fuel.
If that doesn’t work, you need more fuel another way. Get a bigger pilot jet so more raw gas gets into the intake. Adjust your mixture screw. You’ll need to drill and remove it’s EPA plug to do that. (“For off road use only, of course.”)
Long version to explain the short version.
Marty's right on target with the pumper carb idea. But then, you may not want to invest that deeply of your time or money, just so you're bike will start without heat or priming. You may be in information overload right now, but here’s what’s going on.
Fuel vaporizes slower as the ambient temperature drops. Consequently, it takes more fuel to achieve an adequate fuel/air ratio for starting. Liquid fuel will not burn. Guys used to show off by tossing a lit cigarette into a full pail of gasoline (don't try this at home, no kidding) and it would snuff it out…usually. Throw one into a can that's just been emptied and you'd better be somewhere else or soon will be. Gas vapor supports combustion. Liquid gasoline does not.
That said, as was already mentioned, the choke is used to compensate for this temperature change. The trouble is that our bikes don't really have a choke, per se. We have a mixture enrichment device. A choke is a butterfly valve, much like the one on the outlet of your CV carb, only fitted to the inlet. It works exactly the same as placing your hand over the carb inlet. Engine vacuum is directed right to the float bowl rather than to the air cleaner. Consequently, more fuel flows through the pilot jet with the choke closed (on).
The enrichment device on the CV carb has limited ability to compensate for extreme cold. Once we exceed its capability, the next step is to get more fuel of some sort into the intake. Pick your favorite method. Some would simply dump a little raw gas down the air box. (Not a good idea, but if it didn't burn your bike, it would probably start it). Others would use Ether, but as you know, you must pull the seat to do that. You could inject a little gasoline directly through the intake boot with a syringe, then plug the hole with silicone. Creative, but you may not want to do that either. It’s easier than pulling the seat though. You could even run a hose to the airbox to spray Ether through without pulling the seat.
Or you could just modify your carb with a larger pilot jet and low speed mixture adjustment to deliver more fuel when it's cold. That's what I'd do. Of course, using heat is cheating, and it's slow, but it's a sure fire method to get it to fire. A strategically placed light bulb may do the trick.
The theory that Ether shouldn’t be used in an engine is most true with diesels which have more than twice the compression ratio of a gasoline engine. But that’s another story.
As your father in law said, Ether isn't the best thing for some engines, but remember;
all things in moderation. Like tequila, or a good Merlot, a little might do you good.
Good luck.
Shadetree
www.rideok.com "Bill's Garage" Check it out!
Short version.
Make sure you’re keeping the throttle closed when you crank the bike. Don’t touch it. Choke full on before cranking. Once you open the throttle, you lose air velocity through the carb, reducing the vacuum to the float bowl. Less vacuum, less fuel.
If that doesn’t work, you need more fuel another way. Get a bigger pilot jet so more raw gas gets into the intake. Adjust your mixture screw. You’ll need to drill and remove it’s EPA plug to do that. (“For off road use only, of course.”)
Long version to explain the short version.
Marty's right on target with the pumper carb idea. But then, you may not want to invest that deeply of your time or money, just so you're bike will start without heat or priming. You may be in information overload right now, but here’s what’s going on.
Fuel vaporizes slower as the ambient temperature drops. Consequently, it takes more fuel to achieve an adequate fuel/air ratio for starting. Liquid fuel will not burn. Guys used to show off by tossing a lit cigarette into a full pail of gasoline (don't try this at home, no kidding) and it would snuff it out…usually. Throw one into a can that's just been emptied and you'd better be somewhere else or soon will be. Gas vapor supports combustion. Liquid gasoline does not.
That said, as was already mentioned, the choke is used to compensate for this temperature change. The trouble is that our bikes don't really have a choke, per se. We have a mixture enrichment device. A choke is a butterfly valve, much like the one on the outlet of your CV carb, only fitted to the inlet. It works exactly the same as placing your hand over the carb inlet. Engine vacuum is directed right to the float bowl rather than to the air cleaner. Consequently, more fuel flows through the pilot jet with the choke closed (on).
The enrichment device on the CV carb has limited ability to compensate for extreme cold. Once we exceed its capability, the next step is to get more fuel of some sort into the intake. Pick your favorite method. Some would simply dump a little raw gas down the air box. (Not a good idea, but if it didn't burn your bike, it would probably start it). Others would use Ether, but as you know, you must pull the seat to do that. You could inject a little gasoline directly through the intake boot with a syringe, then plug the hole with silicone. Creative, but you may not want to do that either. It’s easier than pulling the seat though. You could even run a hose to the airbox to spray Ether through without pulling the seat.
Or you could just modify your carb with a larger pilot jet and low speed mixture adjustment to deliver more fuel when it's cold. That's what I'd do. Of course, using heat is cheating, and it's slow, but it's a sure fire method to get it to fire. A strategically placed light bulb may do the trick.
The theory that Ether shouldn’t be used in an engine is most true with diesels which have more than twice the compression ratio of a gasoline engine. But that’s another story.
As your father in law said, Ether isn't the best thing for some engines, but remember;
all things in moderation. Like tequila, or a good Merlot, a little might do you good.
Good luck.
Shadetree
www.rideok.com "Bill's Garage" Check it out!