What I have found:
When starting SXs, SRXs, + Vipers, after they have sat for a long time, make sure you have well over 1/2 tank of fuel[ie:FULL].
If you look at the routing of the fuel line from the tank to the pump it has a loop that rises to about 1/2 the height of the tank before heading back down to the fuel pump, because of this the fuel can only get to the pump by its own suction when the fuel level is below the height of the line.
When the fuel level is above the height of the line the fuel will gravity feed to the pump so it will need far fewer pulls as it does not have to "suck" the fuel from the tank.
I have removed the fuel tank fuel line fitting on my SXs + SRXs and turned it upside down with a short fuel line to the pump so I no longer have this issue.[no more loop]
Works for me!
When starting SXs, SRXs, + Vipers, after they have sat for a long time, make sure you have well over 1/2 tank of fuel[ie:FULL].
If you look at the routing of the fuel line from the tank to the pump it has a loop that rises to about 1/2 the height of the tank before heading back down to the fuel pump, because of this the fuel can only get to the pump by its own suction when the fuel level is below the height of the line.
When the fuel level is above the height of the line the fuel will gravity feed to the pump so it will need far fewer pulls as it does not have to "suck" the fuel from the tank.
I have removed the fuel tank fuel line fitting on my SXs + SRXs and turned it upside down with a short fuel line to the pump so I no longer have this issue.[no more loop]
Works for me!
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sideshowBob said:
I was kind of thinking something like this may work as well. I wonder why this loop is there in the first place?
jaydaniels said:
I suspect Yamaha put the loop in for Safety reasons.
If the fuel line is right at the bottom of the tank, routed to a lower fuel pump, you have a lot of weight of fuel trying to flow through the pump into the float bowls of the carbs. In this case you are relying on the float bowl needle + seat to prevent all of the fuel from flowing from the tank through the float bowl overflows +/or into the crankcase. Any vibration,contamination, or wear could cause the needle + seat to allow fuel to flow regardless of float level [ for example trailering]
I had an Improve stock 650 Indy that would actually fill the engine full of fuel occassionally, after it had sat for awhile or had been trailered, it would actually hydraulic lock the engine!
So if anyone is going to reroute the fuel line, be cognicent of the possible side effects! A possible solution could be to incorporate a fuel on/off valve between the tank + fuel pump that could be closed for trailering or storage. Obviously the fuel valve would have to be low and accessable as well.
I personally have not had any issues on my Yamahas since elliminating the fuel line loop on them...but I rarely trailer anymore, since I'm not racing, we trail ride from our door.
JMO
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kirk700 srx
Member
I eliminated my loop also and had 0 Problems so far Knock on wood!!sideshowBob said:
I'm going to try the rerouting method after I get the motor back in. I ended up taking the motor out today to do some wiring and some major cleaning. Hope this works
sideshowBob said:
This might explain why I don't have nearly the same issue as some others for the first start after storage. I start with a full tank of in season fuel and after squirting pre-mix once, maybe twice down the plug holes it'll stay lit. All tolled, about 3-4 pulls.
As you mentioned, the loop is probably a safety and/or cost save to eliminate a fuel shut-off which would explain why Yamaha doesn't have it but all my Polaris' did. The fuel shut-off was pretty high (on the coolant bottle if I remember correctly) on my Polaris' but when you closed the valve, you'd still have fuel at the valve inlet (at the high point). And yes I've filled a crank case too when forgetting to use the valve when trailering. Only had to do that once LOL.
But it doesn't quite answer why some folks have trouble after sitting for a few weeks unless like you said fuel level in the tank plays a role.
Without the added head pressure from a full tank (the level of fuel above the loop), the draw from the crankcase to the pump during cranking/pulling may not be enough to suck fuel over the loop.
Great post Bob and if I might suggest, perhaps a way of mantaining the safety aspect (do we really care about cost saves LOL) would be to eliminate the loop and install a fuel shut off between the tank and pump for trailering. But I'm thinking it may not be very accessable unless you could route it to the left footwell without adding another loop somewhere while doing so.
Some guys here also seem to have more trouble in colder ambients. Hmmm.
From my experience, most people[including me] after a great day of riding usually park their sleds, cover them up and let them sit until the next time they go riding. The fuel tanks are normally just about dry. A few days or weeks go by and we go out to start the sleds so we can take them to where we fuel them up. In this situation the fuel level is definately below the loop and the pump is now having to suck fuel from the tank for a cold start, in cold temps with a cold engine.
We probably all should be fueling up the sleds at the end of the days riding to aid in the next cold start.
JM.02c
We probably all should be fueling up the sleds at the end of the days riding to aid in the next cold start.
JM.02c
007redline
New member
yep
Yeah..lol Hopefully we'll have a good winter...planning on a lot of sledding..party's at the camp weekends..ect When the snow flies it will be every second weekend, Be leaving right from the house.. prob a few hapton runs too...lol Let me know when your ready for some fun..
My srx is in the garage all torn apart, the usual service, 1 leaned out piston(ahhh lol) Friend of mine Ronnie bought a 96 skidoo so that's all apart getting serviced up...and Kyles 600 mxz is also in the garage getting checked over..when the snow flies we'll be ready..
jaydaniels said:
Yeah..lol Hopefully we'll have a good winter...planning on a lot of sledding..party's at the camp weekends..ect When the snow flies it will be every second weekend, Be leaving right from the house.. prob a few hapton runs too...lol Let me know when your ready for some fun..
My srx is in the garage all torn apart, the usual service, 1 leaned out piston(ahhh lol) Friend of mine Ronnie bought a 96 skidoo so that's all apart getting serviced up...and Kyles 600 mxz is also in the garage getting checked over..when the snow flies we'll be ready..
bluemonster1
LIFE MEMBER ONLY ONCE!!!
No one mentioned on here if the Vipers have this same loop thus making them easier to start then an SRX.
MJAREMKO
New member
I think the problem is solved !! Makes sense why Yamaha put the loop in the fuel line for trailering safety.
Either start cold with a full tank or re-route the fuel line with a fuel shut off valve. Hoooray ;-)
mj
Either start cold with a full tank or re-route the fuel line with a fuel shut off valve. Hoooray ;-)
mj
sideshowBob said:
Agreed. Sometimes if we get back early we'll fuel up before putting them up for the night because like you said we're usually near empty but more times than not I'm like a horse to the barn and ready for the couch and remote.
Ride.Race.Live
New member
Yea... this might solve somewhat of the problem... but alot of us just experience it when we park it for a good solid few hours... (long enough for the engine to go cold) then it does it all over again....(if cold out) dont matter how much fuel....
well for me it doesnt.. aslong as its really cold out... and it the engine has time to get cold... ill be pulling her over a good few times
well for me it doesnt.. aslong as its really cold out... and it the engine has time to get cold... ill be pulling her over a good few times
bluemonster1
LIFE MEMBER ONLY ONCE!!!
anyone try looking onto using an electric pump??Wouldn't that be cool.What do the 4-stroke's with fuel injection use diaphram or electric pumps???
bluemonster1...I like your new avatar...it suits you! LOL!
bluemonster1
LIFE MEMBER ONLY ONCE!!!
thanks,kinda like it myself. 
MJAREMKO
New member
I dont ride in temps below zero fairhenhiet much, mine always starts fine after the first initial start of the year, but I bet rerouting the fuel line and installing a fuel shut off valve will help in the colder temps, someone who rides in that type of climate needs to try the upgrade and report back.
mj
mj
I noticed that my 98 SRX had fuel line looped up over the airbox right where it bolts by the handlebars(left hand side). Not sure if my 00 was changed but its definatley different than my 98. My 00 has a loop but it does not go up over the airbox.
PhatboyC
New member
PhatboyC said:For mine same day first pull all the time. After a week 5-7 pulls. First start of the season 100+ pulls. This year I tried rocking the primary clutch didn't help. After 100 pulls I got the plugs out, added some gas and it started first pull. My choke cable is adjusted properly. I looked everywhere to see the gas tank vent tube so I can pressurize it. Couldn't find it.
Which one is it?
Not sure how accurate it is but after adding 20 liters of gas before my first start of the season my gauge showed 3/4 full...still had a hell of a time. Not sure if a full tank would help. I'm sure a primer would of.
sideshowBob said:
Did you try this sideshowBob? Your first theory would be more align from what others experienced.
Just so this thread doesn't get side tracked. We are talking about starting it after a long rest here.
PhatboyC said:
I have installed the new,[which is the original 1998 SRX], fuel pump on my 2002 SRX. The one I removed had the screened vent thru the bottom of the pump, the new one came with the bottom of the pump sealed just like the original 98s.
I am just completing the rebuild of the sled and we don't have any snow yet.
I have not started the sled yet, but when I do, it will be a good test of the pump theory as the tank, pump, lines, carbs, + crankase are all dry. I will count the amount of pulls required and post it.[this sled also has the fuel line loop eliminated]