I see I have another 87 warrior buddy! I had a simular problem with my warrior once we got it to run. Becasue of the age and neglect this machine had seen, it was almost compleatly replaced.

Since we have the "troublesome" acclerator pump it is hard to dial in the carb. How did it run before this problem? I have never had a problem with my brake switch in the past... accually i dont think it works becasue my CDI is 1/2 bad... Also have you changed the spark plug yet, and have it gapped correctly?

When i could not detremine the problem after removeing, cleaning, and sealing my carb and gasket(s), i purchased a rebuild kit. After the carb had new parts in it and a new intake boot it was cured...

For some reason my quad, sometimes when it gets hot, it will not start, the gravity fed gas will not drop. to fix this i just blow in the end of the vent hose to pressurize the tank some and force gas into the carb.

I would also suggest purchasing a reapir manuel.... trust me, they are lifesavers. Also beware if your son is jumping this quad, they have really weak A-Arms and will bend on a harder landing. New a-arms (facotry) are about 135 for this machine... No aftermakret companies make improved a-arms for the frist generation warrior yet.

 

before my son ran it into our pond it ran pretty good, although it had to warm up with the choke pulled out. but after i drained all the water, it never ran the same. i did clean the carb. what i got with the rebuild kit was just the needle. i purchased the new boot and replaced it because the old was torn. is there more to rebuilding the carb than just the needle? i think the quad ran better with the old boot on. the smoke is black, and when it ran decent it was blue not too much blue but some. what is the price on a complete rebuild on the carb. what i paid was around 20.00 for the needle. i do have the repair manual by Clymer. thanks for all your help!

 

That's EXACTLY what happened to mine - it went for an upside-down swim, then sat for 2 years until this past 2 weeks when I resurrected it. I had a new carb on order, but talking with a guy from Sudco convinced me to go thruogh this carb completely.

Mine is the Mikuni BTM 38 carb, with both a slide and butterfly. Your carb should still have an "idle circuit" - this consists of a pilot jet (very much smaller than a main jet, and it's buried inside a tube such that you can't even tell there's a jet in there), and a mixture needle (idle mixture). Gumout wouldn't clean my pilot jet - so I stripped some 12v wire, took a SINGLE STRAND of copper wire, and passed it through the jet with gumout. It cleaned it out and magically the machine would idle once I put it back together. You use the mixture screw to finely adjust the amount of air mixing with the fuel that's coming otu the pilot jet. This is the first step in getting the quad to run right, is idle.

It's safe to assume you have the right jets and needle clip is in the right position, since it's a stock setup. Take your carb apart again, just remove the float bowl and find the pilot jet I'm talking about. mine came out with a small flat-blade screwdriver...

Also, you probably need to adjust the floats. If there's a midrange problem when cruising at light throttle, and you KNOW the carb has the factory tune, you may be running rich because the floats are letting too much fuel into the float bowl. These carbs are sensitive, you actually can tune the lean/rich condition at part throttle with the float height. Baffled me at first, but now I've gotten the fine tuning down. I got rid of the flat spot that my 95 wolverine ALWAYS had from factory, by playing with the accellerator pump and idle mixture...


good luck!

 

as deisel said, you need to tear this thing down ALL THE WAY. MY suggestion is remove the carb and drain the gas... take it inside to the kitchen table and keep all of your parts sorted. From the sounds of it the carb is gummed up.

Does this machine make any popping noises or such when you goose it? Or does it just die like you turnning off the switch? also if you slowly give it gas will it rev up? if so i would say it is your floats. Sure sounds like it is gettin to much gas in there at one time.

btw- my warrior smokes at start up, blue smoke. I am burinning oil even though the dealership "went through the head" Accually we have traced it down to my valve guids.

where did you get your carb kit from? Mine came with a new needle but i refused to use it because it was a diffrient size than my stock one. IT also came with all new c-clips, diaphrams, grammets, springs, and gaskets. I also purchased a new accelerator pump becasue mine was in terrible leaking shape.

 

Just adding one more thing: one common item shared by the Wolverine and the Warrior carbs is the extremely weak accelerator pump spring, mine stuck all the time, made it bog real bad off idle, the perfect fix is a spring from a click type ink pen, it is the exact size, and is about 5 times stronger. Never had a problem after that, and its been in there for years.

 

It does back fire sometimes and stalls. and yes if i slowly give it gas it revs. and last night, i started it and it ran awhile with the choke out. i pushed the choke in, and it actually idled, but gas started pouring out of the line by the bowl. i guess this raises another question for all you guys again. thanks
all i got from the dealer was the needle. what was the cost on what you had purchased (Blaster96)[img]i/expressions/face-icon-small-happy.gif[/img]

 

I forgot to mention the spring in the accellerator pump. Mine was stuck open because of the water that had leaked into the carb. I broke the rubber/plastic diaphragm that holds it in place, which was why I ordered a new carb from Yamaha (not a replaceable part, doesn't show up on the online parts diagram). While I was waiting for the carb to ship, I talked to a guy at Sudco who told me (a) you can run without the diaphragm, and (b) the spring is weak and should be replaced with an ink pen spring!! I had to lightly sand the plunger to get it to move freely - I guess corrosion swelled it enough to get hung up in the pump housing? Anyways, I made sure that it was working freely (not loose though), used the ink pen spring, and it seems wo work great (no off-idle hesitation or stumble).

He's right - take the carb off, and into the kitchen. Get the rebuild kit and install the new gaskets, etc. You'll be able to see what parts go where. Make sure the main jet & pilot jet are marked as the same size - if not, use the ones already in the carb and clean them thoroughly! You should be able to hold the pilot jet in sunlight and see through it. The main jet has a much larger hole, but the same thing goes here - should be able to see through it clearly.

Feel free to email with questions. I wish I had a digital camera to detail the process, because there is disappointingly LITTLE support on the internet for carb rebuild & tuning. Someone should write a "HowTo" because it doesn't take special tools and is relatively wasy to do with instructions...

 

If fuel overflows the floats at idle (and dumps out the vent tube as you describe) there's no doubt that your needle valve and seat are gummed up. Time to take that carb off!

Here's a parts breakdown. Don't let the complexity scare you, you are actually only going to take the float bowl off first (that's the bottom piece held on by 4 phillips machine screws). Yamaha Parts Finder - click on "Carburetor" to see the diagram.

Here's the process I think you should follow:

(1) remove the cover plate (6 phillips screws) so you can ge to the throttle cable - pop it out, then remove the fuel line clamp witha pliers - slide the clamp back and pull off the rubber fuel line at the carb. Drain the float bowl at this time.
(2) remove the 2 nuts holding the carb to the rubber intake (goes to the cylinder head), also remove the airbox and pipe going from it to the carb intake.
(3) Pull the carb out. Take it to the house and clear off the kitchen table!
(4) Upside down, remove the float bowl (4 screws). The MainJet is the big jet you remove with a flat-blade screwdriver - remove & clean it so you can see through it.
(5) Remove the floats GENTLY by pushing out the pin that the float is attached to (and rotates around). There will be a small metal piece that connects the floats to the Needle. The needle is supposed to open & close when the floats go up and down - your needle is obviously not closing because it's gummed up or clogged. Try not to bend the metal piece - it controls the fuel level and is important for tuning later on.
(6) Use a small flat-blade screwdriver that fits in the tube with the "pilot jet" (much smaller than the main jet) and remove it (counterclockwise). I'm sure yours is clogged from the symptoms you describe! Mikuni recommends against it, but I had to pass a single strand of 12v wire through mine, using Gumout, to get it cleaned.
(6) Use Gumout or carb cleaner to spray through the other tubes / holes you can see with the float bowl removed. Each hole / tube is either for air or fuel and MUST be cleaned!

I'm betting you do NOT need to take any more of the carb apart (top cover, etc). If you make sure the pilot jet, the machine should run like it was brand new...

email me if you have more questions. Maybe I could take some pictures when I take mine out next - I am trying different needles tuning my wolverine so I will have it out again next week...

-scott

 

you guys are awesome. i waited way to long to join this forum. i am going to take care of the carb this weekend. wish me luck. i will let you all know come monday. thanks again for all your help.

 

I just joined a couple days ago. Was looking for help with my carb. didn't find it here, but figured the next guy I ran into with similar symptoms could use some help. I'm only a shadetree mechanic, but was able to figure it out.

Here's another link I found with a tuning guide to Mikuni carbs. It's for a Harley Davidson carb - but has the EXACT same four circuits that are found on your warrior carb: (a) Choke System, (b) Idle System, (c) Main System, and (d) Accellerator Pump System. This guide helped me understand how the Mikuni on my Wolverine worked... <a target=new class=ftalternatingbarlinklarge href="http://www.mikuni.com/pdf/hsr_tuningmanual_021003.pdf">Mikuni Tuning Guide
</a>

In the case of your warrior, since it isn't idling right - focus on the Pilot Jet and air screw (air screw probably won't need adjusted, try not touching it first). Also, since you are venting fuel, you know that your needle valve is plugged up (just replace it - new needle and seat are $34 from yamaha dealers). The only adjustment you might have to make is to the float position. If, when you put it back together, the ATV runs ok at Idle but still bucks and jerks at part-throttle cruising, there is too much fuel in the float bowl and the float will have to be set to close the needle valve earlier (bend the lttle metal piece that connects the float to the needle).

Good luck!!! I'm leaving tomorrow for World Forld Challenge in St. Louis. We're competing in Outlaw Street class with a street-legal, 8.90 second 1995 Mustang. It runs a PT-88 turbo with custom Electronic Fuel INjection setup. No carbs to hassle with there!! I'll be back on Sunday night and will check the forum then. I hope your project goes easily - if you get stuck, just take a break and contact one of us online.

-scott