hard start issue

[VT_BluYamaha54]

it is very strange.i dont use super,my sled stays in my garage(cool),fuel would take months to go bad i would think.when it does start there is not much black smoke.if it was flooded wouldnt you see this to some degree?when i pulled the plugs they were dry.if it was a check valve wouldnt it do it over nite?choke worked fine next day5-10 degrees started right up.when it wouldnt start eether wasnt making it kick either.and i dont smell fuel when its cranking and not starting. :?

LB - The sentence that bothers me most is why he isn't firing after a shot of ether?? No reaction from the engine after a shot of ether usually means the valves aren't working right or there is no spark.

Snappy - where are you spraying the ether? That should give you an immediate pop from the engine. Does your battery give good cranking RPM after one of these 2wk cycles of sitting? Maybe he isn't getting enough cranking RPM to create good spark and vacuum??

 

[JDKRXW]

I'm having similar problem but worse. I have to take out the spark plugs and turn it over. Stuff comes pumping out of there. I put the plugs back in and it then starts. A real pain in the A$$. It happens probably every other time. I'm taking it back to the dealer to fix.

This sounds like something completely different than the other hard starts here. As LB says, your engine is flooding. Do you have to trailer to get to the trail?
- you should make very sure your engine isn't starting to hydro-lock (having fuel siphon into the engine, through leaky float valves in the carbs). Shaking on the trailer can set up this condition (see your owners manual)
- if it is simple flooding, open the choke, and hold the throttle wide open until it starts.

 

[Honk]

This happened to me tonight! I have not run my 03 rx for two weeks. I put it on the trailor after the ny, ty ride. Closed the fuel shut-offs and drove home. so it has been out thier two weeks, hot and cool weather. I pulled the choke and it ground and would fire just a bit but not start. I tryed less choke no better. I tryed cracking the throtte, made it worse! I hooked up a jumper battery and no better. It had a half tank gas. I put a heater on the carbs for two mins and then it finally started, but still rough running. it did clear up and then ran fine. After it was warm I tryed to restart, no problem, so I really don't have a clue either? anymore thoughts guys? HONK

 

[LazyBastard]

- if it is simple flooding, open the choke, and hold the throttle wide open until it starts.

That should be *CLOSE* the choke. When you're already flooded, the last thing you want to do is add more gas.

 

[DYNAREX]

SOUNDS LIKE VALVE ADJUSTMENT IS A LITTLE OFF-NOT ENOUGH VACUUM TO ATOMIZE FUEL-IT HAPPENS A LOT ON THE SMALLER QUADS IN MY SHOP-ADJUST VALVES AND BAM FIRES UP INSTANTLY AFTER SETTING A FEW WEEKS
ITS NOT A CHOKE ITS A FUEL ENRICHER-KINDA LIKE A EXTRA MAIN JET THAT WORKS AT LOW SPEED

 

[snappy]

when i put the ether in i had the air filter lid off,had someone open the throttle and i shot all four carbs about 1 second each.some one said adjust the valves?in the valve train?i thought the first time to check valve lash is at 25k.i talked to a motorcycle guy today familliar with yamaha street bikes he said allot of 4 cyl carbed yamaha bikes will drain the carb bowls back to the tank after sitting for long periods of time.but that dosent explain it not firing right up with ether.

 

[DYNAREX]

id do a hot and cold compression/leak down ck
also ck vac readings at idle on all 4 cyls and definatly synch carbs

 

[VT_BluYamaha54]

My Warrior hadn't run for exactly 2 weeks and had been in my enclosed trailer parked outside. Weather has been all over the map - typical New England. Some days 40-50; others high 20's to mid-30's.
Anyway, it has snowed some more so there is a bit more riding in isolated pockets here so I decided to go out and enjoy.
The sled cranked OK for about 12secs and fired but would not stay running when I followed my usual practice if immediately getting the choke all the way off. From the way it acted, I would blame poor fuel quality. It ran good when last run and the tank was a bit over 3/4 full of regular gas. It usually settles back to a high idle wfter it recovers from the choke but this time, I thought I was going to have to hold the throttle a bit to keep it from stalling. Another three attempts to start and it remained running but the NOISE from the primary/reduction unit was AWFUL. It continued for about a full minute and got better but did not go away altogether. I have noticed this getting more noticeable with miles - now about 1,800. Is this anything to worry about? Since I ahve had allot of overtemp issues I am concerned there may be more to this than an engine that "dried out" of oil from sitting.
Does anybody have ideas?

 

[Snomad]

I have had this problem twice after the sled sat for more than two weeks without being run. Seems to me to be no gas in the carb bowls for whatever reason and it takes quite a while for it to get there. I tried Lazy's trick of pressurizing the tank but found it a pain to get at the vent line without creating damage. If someone that has gas shut-off valves closes the valves and lets the machine run out of gas this would duplicate the problem. I think they would have a problem getting the machine going again right away too. If one were going to install these gas shut-off valves, would they be better on the output side of the fuel pumps?

 

[Rmudmaster]

Anyone have a hard starting problem when the sled is all ready warmed up ? ( after riding ) I have to crack the throttle a little as I hit the key and it starts right up. But, if I just hit the key it will just turn over like it's not getting any gas . Any Ideas ?

 

[VT_BluYamaha54]

Anyone have a hard starting problem when the sled is all ready warmed up ? ( after riding ) I have to crack the throttle a little as I hit the key and it starts right up. But, if I just hit the key it will just turn over like it's not getting any gas . Any Ideas ?

Yes, that has been identified in other posts here.
For some STUPID reason, Yamaha didn't include a shutoff valve for the coolant going to the carbs. Since they don't need heating unless ambient temp is about 20F or less, they get :heat soaked" when you stop. If you notice, you will also get a fairly strong gasoline smell.

Check float levels to be sure they aren't too high and add a valve in the 1/4" coolant line above the valve cover closest to the PTO. Most have recommended the SkiDoo valve as it is small.

 

[smokeless1]

hard start issues

LB is right. These carbs are running very hot. So when you shut down lots of the fuel in the carbs are evaporating. Also if your tank vent is not functioning properly, the expansion in the tank can cause the floats to jam and then when the fuel evaporates, it will take some real pressure to unseaat them again. Had an articat do that for half the season til I began cracking the tank cap. Problem went away. Fixed the vent hose and issue disappeared permenantly.

Do yourself a favor and install a fuel shut off, which should have been standard equipment in the first place. Then shut the valve off and let the machine run for one minute before killing it. Bet this will prevent this from happening.

Also install a valve in the coolant to carb line. Not sure why they have a hose the size of the detroit water department peach island inlet, taking all that very hot coolant to the carbs, but it solved several of my problems on my 04, once I did.

Okay, now:

A) Gas shut off valves inline to both fuel inlets.
B) Temperature Gauge to see what the heck is happening under the hood
C) Coolant shut-off to carbs set at 90% closure most of the time unless it is colder than siberia.
D) Rear heat exchanger to cool the beast down.


Should look at the 05's for the touted "improvements" to see if I missed anything.