help identify fuel lines?, I'm not getting fuel - Snowmobile Forum: Your #1 Snowmobile Forum

Ryan77 · 11-16-2005, 06:15 PM

hey all, this is Ryan with the old jalopie motoski again(1973 440) and now(thanx to all u's help) she fires.....pretty good i may add.....and runs great on starting fluid.....but I have noticed it is'nt drawing any fuel....the lines on the carb. I think I have them going to the right places.....I think......"in the pix attached" I am pointing out what I think to be true......correct me if I'm wrong....please.....I have no primer bulb....(this sled not currently equiped) I have a 1/2 tank of gas and it is'nt pulling any fuel out of the tank....now the fuel lines enter the top of the tank.....so....it has to suck it up a bit to get it started.......should it be able to do this on its own?????/or do I have a vaccume leak somewhere......is the line that goes between the engine and the carb vaccume???? and the line that comes out of the bottom of the carb.....it goes to the fuel tank also.....I think it was hooked up that way.....the fuel tank has 2 nippels......any info is greatly appriciated.....(on the pic...hit "next" to view the next pic in my album....it shows the other fuel line.....I'm thinking this is the main???)

http://pg.photos.yahoo.com/ph/hddman...1b.jpg&.src=ph

steve03052 · 11-17-2005, 06:45 AM

Your labling in photo carb1 is correct. The bottom line is the supply from the tank. The hose going into the side is the "pulsation" from the crankcase. On the SkiDoos there are two hoses from the tank. One is a supply and one is a return. Tillys are setup like the mechanical fuel pumps in old Chevies. They pump way more fuel than they need and have a second line to return fuel to the tank. That may be what the second nipple you point out in carb2 is.

These are going to sound obvious so bear with me.

Is the line from the tank clear? Can you get fuel through it?
One of my old sleds has a dip tube in the tank that broke off and I could only get at half the fuel in the tank.

Does the drive hose from the crank case have any leaks?

I try not to run my sleds on ether. It does not have any lubrication in it. You're better off getting some kind of squease bottle and putting mixed gas in it to prime with.

Take a look at this:Tilly Diagram just to be sure the carb is back together correctly.

IndianRvrShiver · 11-17-2005, 06:57 AM

With that type of carb, it appears that you have it connected properly. The line from the engine crankcase to the carb is a pulse line, not vacuum; it is that pulse that causes the diaphragms in the carb to pump the fuel. If working correctly, it should have no problem "pulling" fuel from the tank.

A couple of tips......make sure the fuel lines are not cracked/split or collapsed; suggest new ones for a sled this old. The pump diaphragms may be old & dried out....you can take the carb apart & soak them in fuel overnight to help return their flexibility. While it is apart, check to make sure the inlet needle is not stuck in the seat. Make sure the line going into the tank is actually reaching the bottom of the tank and is in good shape. Start your adjustment needle at 1 turn out on the low speed & 1-1/2 turns out on the high speed

When you get it to fire on starting fluid, apply the choke butterfly (if equipped) or put your hand over the carb opening to act as a choke. Doing this will help pull the fuel up to the carb.

Let us know how this works!!

Ryan77 · 11-17-2005, 07:05 AM

the lines inside the tank I just replaced, and the metal fitting they attach to(the one that passes thru the tank) I cleaned and is clear......and the line that goes to the bottom of the carb is used....but clear and useable....and the return.....is a new hose.........now,...the only one I havent checked is the one that goes from carb to motor(pulse).......my neighbor said to see if its sucking vaccume(pulse)......hold a lit cigerette near it and when you pull the rope see if it draws in the smoke......so thats next on my list......then a new gasket set in the carb. since I just carefully took it apart and reused all the old gaskets......I've done it on cars and have pulled it off so on this old sled i thought what the heck..
and I would have never knew that the hose on the bottom was were it was fed from.....(being a motor bike mech.) I would have thought it was overflow......at first I thought someone must have been goofing around with it to have hooked it up to the tank.....I keep thinking about fuel bowls ......lol...i keep calling it the bowl...but yea I'll try those things....and tell ya what happens....I just got some clear line....so now I'll know whats going on....

**smallengineguy** · 11-17-2005, 07:14 AM

On the line in the tank, is there a check valve on the end of it? All Moto Skis had a check valve in the tank so the fuel wouldn't go back into the tank when it wasn't running.

Ryan77 · 11-17-2005, 07:21 AM

Hmmmmm....you know there was a filter looking thing on the end of one of the lines on the inside of the tank.......and it was too deteriated to reuse......I thought it was " just" a filter......I rember when I tried to clean it....using a needle it seemed I could'nt poke thru cause of something round stuck inside.....I bet you are right.......is this part essential for this sled to run????

steve03052 · 11-17-2005, 09:05 AM

It will run without the check valve, but it's a real pain to start because you have pump the air out of the fuel line before you get any fuel at the carb. On my sleds that equates to about 20 pulls on the starter rope (no thank you!)

IndianRvrShiver · 11-17-2005, 01:27 PM

Quote:

Originally posted by Ryan77
Hmmmmm....you know there was a filter looking thing on the end of one of the lines on the inside of the tank.......and it was too deteriated to reuse......I thought it was " just" a filter......I rember when I tried to clean it....using a needle it seemed I could'nt poke thru cause of something round stuck inside.....I bet you are right.......is this part essential for this sled to run????

That is also a heavy piece to make sure the fuel line/pick-up stays on the bottom!

Ryan77 · 11-17-2005, 02:01 PM

yea I put a small lawnmower filter on that one and used a small metal hose clamp....it stays at the bottom.......but it will defantly do the 1-way valve thing.......I'll hav to look one up.....the better it starts.....the better

**smallengineguy** · 11-17-2005, 05:34 PM

Yeah, the check valve is a must on the Moto Skis, unless you like pulling on them....

Ryan77 · 11-17-2005, 06:14 PM

ok....I got home from work....took the "clear fuel line"and installed it......the one that was "used but useable" was cracked where it went on the bottom nippel...(i never noticed)....so I put the new clear line on and filled it(the line) with fuel....hence getting fuel in the carb.....then I hooked it to the tank......pulled the cord and it fired up.....and ran....and ran....and did'nt die....I could see little bubbles in the fuel line trickeling,.. I let it warm up for about 5 min......and reved it up a little....I have the rear on jackstands so...the belt was moving....it seemed to run fine....no choke needed......now my question is.....would you all call it good to go.....the only thing I did to the carb was dissemble it to the piont I could flush the bottom half(it was'nt really dirty at all) and blew carb cleaner thru the main and secondary screw in/out valves and other small openings...wereas it seemed to trickel out somewhere else.......and reassembeled....and no leaks runs fine....now.....someone mentioned leaning out and burning up.....I dont want this to happen......should I just buy gaskets/needleand seat and totally rebuild this tollitson HD.....???? what would the symptoms be if it were running lean....lean to the point it burns up??????

**smallengineguy** · 11-17-2005, 07:09 PM

You won't be able to tell until you get it on the snow, and run it at higher speeds. Look at the plug chart in the engine section to see how it's doing.

IndianRvrShiver · 11-18-2005, 06:49 AM

You can easily adjust the high-speed jet (one with the pin). Start out at about 1-1/2 turns out. Adjust it until the engine does what we call "4-cycle"(dadadadadadada...), then screw it in 1/8 turn at a time until the engine cleans out & begins to produce power (waaaaahhhhhh). You always want to be on that edge; you may need to adjust it every time you ride & also with varying temps. Also do what SEG said....watch the plugs!

**smallengineguy** · 11-18-2005, 06:55 AM

I gotta remember the dadadadadada and waaahhhhh.....

Ryan77 · 11-18-2005, 07:00 AM

ok..(verry good tips, I'll defantly do that)...so, regardless of how dirty the carb may be, it always has the potential to burn up, if.. the "pinned" adjustment is too lean......so... if ....I run it at its(current state)......which does run good..(running on the jackstands reved up)...and adjust the "pinned needle from the dadadadada....to the whaaaaa.....it'll be alright????

when I get this thing out in the snow.......I'll defantly run her down the road with the hood off tweeking this thing for the "Whaaaaaa"........I can't wait......

I've tweeked bikes running up and down our county road for years......lol

so...would ya say go ahead buy the carb kit, hold off installing it ,and wait for snow and see how she runs?????make the adjustments.....hear the Whaaaaaa......then check plugs...(which I routinely do on my bikes as well)........

IndianRvrShiver · 11-18-2005, 02:54 PM

Not on the stands...........must be under load!

C'mon, SEG, I guess i could have included a sound file!!

**RJ Gleason** · 11-18-2005, 03:58 PM

with those older carbs, it's always a good idea to have a rebuild kit handy. You may need to get only the fuel pump kit instead of the complete rebuild kit. preset the jets as instructed previusly and tweek as needed. Remember to make SMALL adjustments and keep track of exactly what you did so that you can go back if needed. have fun with the old beater and learn a lot about it in the process.

Ryan77 · 11-18-2005, 06:16 PM

ok....that sounds good......before ordering....what is the difference in the complete kit vs. just the fuel pump part kit......I've had this thing apart and can't really see much else you would need...(really just the 3 gaslets in the bottom)...is the comlpete kit overkill....(i know on the complete kit it stated no needle and seat included).....that would be the only thing other than the gaskets that I would think would ever need replaced????..other than the $15 difference in price????do needle and seats wear out often on these 2cycle machines???think I'd need it???

**RJ Gleason** · 11-21-2005, 05:22 PM

just get the lower gasket set (fuel pump) for the spare. you should not need the rest any time soon. the fuel pump kit contains the diaphram and the other gaskets and valves needed to rebuild the lower part of the carb. (these are the parts that go bad over time)

Ryan77 · 11-22-2005, 04:18 PM

yea I'll do that....the other day when I tried to start it(it usually starts the 2nd pull or so) well it did'nt wana start....it kept flooding the plugs wet......time after time.....so I took the fuel lines off....drained em.......dried the plugs again.....then it started right up....I quickly hooked the fuel lines up....and it kept running fine.....and has ever since.....you think the needle and seat were clogged with sumthing to do that????