Walbro carb. problems

Route 6x6 Discussion Board: Shop Talk: Tech Tips and Q&A section: Walbro carb. problems
Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jerry Ikemire on Unrecorded Date: Edit

I have an old Hustler with the CCW 340 engine. It has a Walbro carb. on it. The thing ran fine a week ago. Today, it won't start. There is good spark. I can take the plugs out and put them by the hole with the plug wires on and crank it. It shoots 6 inch flames out the holes, but it won't even burp when the plugs are screwed in. I've changed plugs with the same results. I even put another carb on it, still won't fire. Looking down the throat. I can see standing fuel in the elbow that goes from the carb to the cylinders. What is this thing's problem?!?

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Attex Bob on Unrecorded Date: Edit

Jerry it could be a ton of things but I will give it a shot.
1. Put the engine back together but take the air cleaner off. Shoot some ether into the carb and crank. Does it start? Does it try to start? Does it pop? Does it pop through the carb or exhaust?

If you have good spark and you have the latter two problems you might have sheered the key on the mag?

What do the plugs look like when you take them out? Are they wet? Real wet? Dry?

Something you might want to do is a compression test. This started all of a sudden so you should not be down on compression, but it is aways a good check.

Do some of these tests and get back to me.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jerry Ikemire on Unrecorded Date: Edit

Attex Bob,
I've run ether into the carb with no results. No pop, backfire or anything remotely hopeful. The plugs are wet when I remove them. They are not dripping fuel, but I can put a match to them and they'll light for a second or so. Compression is good and equal to both cylinders. Tell me more about the mag key. Is it similar to the flywheel setup on a Briggs single cylinder, in the respect of a timing issue? Thanks

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Kevin Percy on Unrecorded Date: Edit

Jerry,
Are there drain plugs on the bottom of the crankcase facing the same way as the carb ? The engine might be badly flooded and there is gas sitting in the base. Unscrew the plugs if you can find them and if fuel runs out, shut the ignition off (so you don't create a spark and start a fire) and with the spark plugs out crank the engine over for a few seconds (maybe 10 pulls with the manual starter ?)to blow all the fuel out, then try to start it again with fresh spark plugs and the drain plugs back in after you mop up any fuel that has drained.
Is your fuel tank higher than the carb ? Maybe the fuel inlet needle in the carb has stuck open and the tank has drained into the engine ?

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Attex Bob on Unrecorded Date: Edit

Let me say first that I am no expert on this engine. I am just guessing on the mag key. If you know the Briggs setup I am just guessing it is the same setup on your 340. My Super chief runs a set of coils and points like a car. (old car!!!) Yours could be the same.

I broke a mag key on a briggs once it had the same symtoms. It drove me nuts because it had all of the things to make it run. One time it would pop through the carb and another time it was through the exhaust. But lets say your ign. lights off on the intake stroke. You will have spark but no pop or anything else.

As I'm sure you know, any ignition setup needs to be timed and there is usually some part that can give in case something gets jammed. A key, a pin, a bolt, something and that part may be the cause of your problem.

If you can light the plugs with a match, that sounds very rich to me, but hard to say when I'm here and your over there.

Jerry, if you are like me you are probably really frustrated by now!!! It sounds like you are doing all the right tests but you are missing something small. Just keep in mind that this thing only needs three things to be happy. Fuel, (in the right amount) spark, (at the right time) and compression (just enough to get the job done)

You might try turning the engine over real slow and see when the spark goes off in relation with the piston.

By the way, what compression did you get?

Don't give up, do some more checks see what you come up with. Good luck Jerry.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By r.wolf on Unrecorded Date: Edit

try the ether again and switch around your plug wires.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By liflod (Liflod) on Unrecorded Date: Edit

Use a timing light to check the timing. Also check that you are using the correct plug gap. If the gap is too big, it will not spark under pressure. Also the point gap should be checked. If it is too small or too large, it would have the same effect as the plug gap. Even if you think the plug gap is correct try closing it a little . I think .018 is about as small as you want to go.

Lance

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jerry Ikemire on Unrecorded Date: Edit

Kevin, I couldn't find any drain plugs as you described. Also, the gas tank is in the front and actually sits a bit lower than the carb.
Bob, the compression is around 60lbs, give or take, on both cylinders. It sure seems as though the plugs fire at the tdc of the piston on compression. Also, when the plugs are out, I can put the wires on them and set them over the plug holes. They fire blue flame every rpm.
R.Wolf, switching the plug wires does nothing.
The carb has 3 adjust. screws, 1 for idle, 1 on the side and 1 in the front. Anybody have an idea what the 2 other than idle are for?
Thanks

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Attex Bob on Unrecorded Date: Edit

Kevin, 60lbs is not a good thing. My 500 has about 155 in each hole. I don't know the spec's of the motor you have but that does not sound good for any motor. I don't think that is your problem if the engine ran good before that, but the compression is not good. You will have to do a rebuild soon. I just redid my golf cart with 60psi and it was ugly!!! 1 broken ring, a mile of play in the piston, and only 1 crank seal!!!! I could not believe it even ran!!!!

Maybe someone can chime in here and confirm this?

On a two stroke engine, vacuume and pressure is everything.

Kevin might be right and the engine is flooded badly. This could be washing all the oil off of the rings and causing bad compression? You might also look at the reed valves and see if they are ok? Some crap under them might be causing compression problems? Make sure the engine is really "dried out" before you try ether. I would even go so far as turning off the fuel while you try this.

The ether should make the thing pop or light off even at 60lbs? Give it a try and get back to us.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jerry Ikemire on Unrecorded Date: Edit

Another thought just hit me. I don't know the insides of 2 strokes very well but don't the crankcases have to be under pressure? Do seals keep that pressure in and how easily can they blow? Also, earlier I stated comp. was around 60. Meant to say 90+. By the way, out of idle frustration I took the motor out. Guess I had to say I did something that worked. Now I can clean that part of the insides.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By david berger (Davidrrrd) on Unrecorded Date: Edit

I THINK SOMEONE HERE HAS SAID THIS BUT YOU DO NEED TO SHUT DOWN YOUR FULE LINE WHEN YOUR DONE FOR THE DAY, AN INLINE SHUT OFF WORKS GREAT FOR THIS, RUN TILL ALMOST DRY OR DRY IF YOU LIKE, IN THE VERY LEAST SHUT FULE OFF SO TANK WONT RUNN INTO ENGINE IF THE VENT IN THE TANK IS CLOGED AND TEMP RAISES IN TANK, OR SOME SUCH SENAIRIOW, IT'S BIN KNOWN TOO HAPPEN FROM TIME TOO TIME AND IT'S NOT A GOOD THING TO HAVE TOO DEAL WITH, A FLOODED ENGINE CAN CATCH FIRE WHEN YOU TRY TO START IT,IT CAN BE A REAL BUGGER TO CLEAN IT OUT TOO,
I HAD GASS FILL ENGINE AND RUN OUT THREW LEAKS IN EXAUST THAT DRIPED FULE ONTO MY BELT, I TRYED TO BLOW THE FULE OUT WITH A QUICK PULL ON THE PULLSTART WITH FULE LINE NOW SHUT OFF AND POP, MY BELT AND EXAUST WERE ON FIRE, IM LUCKY THERE WAS A 2 LITER BOTTLE OF SOADA NEARBY, (DON'T LIKE PEPSI ANYWAY)
ALWASE SHUT OFF FULE BEFORE TRAILERING ON LONG HAULES AS AGITATION OF FULE TANK MIGHT RAISE TANK PSI HIGHER THEN NEADLE VALVE, ECT..ECT..

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Kevin Percy on Unrecorded Date: Edit

Attex Bob,
I agree 60 lbs is not good, even 90 is not great, but it should run. The gas washing the oil off the cylinder walls is a good thought, but this is a two stroke and the oil is mixed with the gas.
I don't think that engine has reeds, but you are right, if it does and there is something holding them open he will lose crankcase compression.
Jerry,
I would check the flywheel key while the motor is out and it is easy to see. Then I would put the motor back in and leave the fuel line disconnected and try to start it with fresh plugs. If you get nothing, pull the plugs and if they are dry put a little fuel in each cylinder and try again. It they are wet leave them out and spin the motor over to blow that extra fuel out and try again. If it starts and runs on the fuel you put in the cylinders, then I would suspect the carburetor(s).
Dirt in the wrong place or a hole in a carb diaphragm will cause flooding.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By r.wolf on Unrecorded Date: Edit

jerry ikemire, 1st is idle 2nd and 3rd is low and highspeed jets. low speed is closest to the engine. inital setting is 1 turn out.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jerry Ikemire on Unrecorded Date: Edit

Thanks guys. It'll be another week before I can get back to it but I'll let you know what other problems I find as I dig deeper.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jerry Ikemire on Unrecorded Date: Edit

Well I found a few minutes to monkey with this again. The key was not sheared off. Both sets of points looked good. The seal on the end of the crankshaft looked new. No eveidence of fuel around it. Where do I go now? Crack the motor open to check the inner seal? I'm almost to a point of selling the whole ball of wax. My wife was kind enough to point out I could use the room!

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Attex Bob on Unrecorded Date: Edit

Jerry, I'm sorry you did not get it running again; yet.

I think Kevin is giving you good advise. I would do just like he said in his last post.

There is only one more thing I would check when the engine is out, and that is the reed valves or the rotary valves. It will have one or the other. It should be easy to check with the engine out. I would not tear the motor down any more than it is. Sounds like everything is ok inside.

The more I hear about this the more I think Kevin is on the right track with the flooded engine.

Give it a try and let us know what happens?

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Jerry on Unrecorded Date: Edit

All right guys, I finally got back to it today. I put it back together and back in the machine and put ether to it. It fired right off and ran unitl it ran out of ether (I gave it about a full second shot). I next put a shot of gas in the carb and it did the same thing. Now all I need is where to get a Walbro rebuild kit, if there is such a kit. I'm figuring the gas was being allowed to run on, like a stuck float in a conventional carb. And thanks to all who tried to help me, I greatly appreciate it.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Big Bob Hall on Unrecorded Date: Edit

Jerry

Check with Richard Clark about that kit, also check
you compression of your engine, must have around 110 lbs
to run

Big Bob Hall

Top of pagePrevious messageNext messageBottom of pageLink to this message   By schunn on Unrecorded Date: Edit

Im having similar problems with my 400 JLO. It seems like it runs as long as it is cool, Let it get hot and it don't want to run, althouhg it will spark nice blue sparks when turning the engine over and the plugs can get wet at times.

Im thinking I may have an electrical problem that is intermittent. Im struggling with trying to get the magneto off of the end of motor. Man it is a bear to get off. I am going to try to get 3 long bolts so that I can put a flat piece of steel over the 3 bolts and then tighen down on the bolts to pull the magneto off of the motor.

I would like to change points and condensor. Does anyone know where to get replacement parts for it? I went to sled parts.com, where they have parts but the site does not indicate which of the engines they will fit. Can't get the magneto off to inspect and see if the store parts are the same as mine that is on the motor.

I drained fuel into a glass jar and did not see any water at the bottom of the jar.

The idle mixture screw adjustment has zero effect when you turn the screw in or out. Could this be my problem?

Any help would be appreciated.

Steve

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Sam Keys on Unrecorded Date: Edit

Steve;

Sounds like your top end may be worn out, many times
they will start when cold then not when hot, compression
should be around 120 lbs in each cyl.

As I have said many times before, Richard Clark owner of this
site has most JLO stuff in stock, including points.

My new dealership will have most common Route6x6 parts
in stock with in two weeks.

Just contact richard for your needs

Sam Keys

Top of pagePrevious messageNext messageBottom of pageLink to this message   By David Keeso (Argomag) on Unrecorded Date: Edit

Sam, can you really wear out the top end?? What exactly does this mean, you just don't have the same level of top end power/speed? If so, this is sounding more like the engine on my ARGO MAGNUM. Runs great when cold and while heating up at first, then when the temp gauge starts to get closer to the mid level, the engine seems to loose the peak power it had while cold. It doesn't cause the ARGO to slow down really, but it just seems like it revs a bit higher while cold, and then not as much when warmed up- Is this similar to what you are describing?

Because we aren't at the cottage all the time, the ARGO sits in the garage, (non heated) so the choke is always a must- (will not start cold without obviously) but as soon as the engine will stay running without the choke, I go. Could this be the problem? Not giving enough running time with aid of the choke?

Thanks

Top of pagePrevious messageNext messageBottom of pageLink to this message   By John Martin on Unrecorded Date: Edit

David--Normally when they talk about the "top end" they mean the rockers, valves, head, head gasket, cam shaft, reed valves, etc. As opposed to the "bottom end" consisting of the crankshaft, crank bearings, oil pump, etc. I think some people consider the connecting rod, piston, and piston sleeve as part of the "top end" too. I listed various parts but not all engines share these same parts, 2 strokes have less parts than 4 stroke motors have. Sometimes when people rebulid an engine they just bore the engine block and or resleeve it and install a new piston and piston rings without going through the "bottom end" and changing the crank shaft and its bearings. Maybe that will shed some light on the subject for you.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By argomag on Unrecorded Date: Edit

John Martin- my appologies and thank you for explaining it= i was waaaay off. If you rebore the piston sleeve, wouldn't that make it wider? WOuldn't you have to rebuild the sleves to fit tighter? I don't have the slightest clue about the internal components and how they work etc. I know that you put the key in, start it, and go. Maybe a basic amount of info on how the cycles go but nutin else

Top of pagePrevious messageNext messageBottom of pageLink to this message   By schunn on Unrecorded Date: Edit

Help!

On the 400 JLO, I managed to remove the magneto wheel to gain access to the points, condensors and coils. I have new 2 piece point sets ordered and 2 "long" condensors. I see a "minor" amount of oil has come into the housing. Maybe thru the crank seal. Don't know yet. The "double coil" appears to be damaged. It looks like the double coils are secured with slotted head screws at the ends of the coil. I have not found a screwdriver that will fit into the holes to access the slotted screws. I have ground down several small, thin screwdrivers, but still they will not engage the slots. Am I on the right track to remove this coil? The other coils, i believe is the alternator. It came loose after removing its mounting screws. I suppose you will need to pull the wires thru the crankcase to get them out. I have seen pictures of the magneto coils on ebay, that look like the points, coils and condensors mount on a round plate that screws on to the motor. Is that the way the 400 JLO works?

I have a spare 400 block assembly that I will look at to see if the pistons are as loose as on my "good" motor.

Steve

Thanks

Top of pagePrevious messageNext messageBottom of pageLink to this message   By schunn on Unrecorded Date: Edit

400 JLO with sloppy fitting pistons:

I opened up my spare 400. The pistons are nice and tight within the cylinders--no noticeable movement when you push them side to side. I am thinking I should move the cylinders, pistons and heads from the spare 400 over to the "good" 400. Is it possible to do this with a minimum of fuss and without purchasing new pistons or rings?

Is there much more disassembly needed to remove the cylinders from the crankcase ?

Steve

Thanks

Top of pagePrevious messageNext messageBottom of pageLink to this message   By dt5428 on Unrecorded Date: Edit

Don't take this the wrong way because it sounds like you have the want and just need some help to rebuild a motor but I think maybe you should find a friend or someone in your area that has rebuilt engines who can stop by and help out.Take this for what it is worth but a couple of mistakes and your wallet will be lighter and you will be starting all over again.Just a thought.

Later,Dan

Top of pagePrevious messageNext messageBottom of pageLink to this message   By David Keeso (Argomag) on Unrecorded Date: Edit

Schunn, because I don't really know what your situation is with the engine, I may be in the wrong as I usually am, but wouldn't it be easier to just swap engines in your machine? By the sounds of it, the spare is better than the one in the machine now-again, thats just what I got from skimming through the posts.

I also don't know the value of those engines, but what if you sold both and got a newer, running one ready to run. Just a thought im sure you've already thought of, but hey! its worth a shot.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By schunn on Unrecorded Date: Edit

David

Yes, it would probably be easier to just swap except for the fact that I don't have a complete spare and the ignition system visually appears to be different. When I removed the stator wheel from the "good motor" it appears to be totally different from the spare and I do not think that the magneto will transfer from good to spare motors. The spare motor appears to have the magneto parts removed and in its place, it appears to have a different type of flywheel. Unless the magneto is behind this flywheel, I dunno. If I sent a pic of the ends of both motor, could you visualize if they are compatible?

Thanks

Steve

Top of pagePrevious messageNext messageBottom of pageLink to this message   By schunn on Unrecorded Date: Edit

Dan

No, I do not take your comment the wrong way. Part of my trouble is that in Memphis, TN you don't find a lot of 6 wheelers or snowmobiles. In fact, I bet you would not find any JLO motors and very few people that know anything about them, or have even heard about them.

I get a lot of information from this site.

I have a young relative who has taken a program in small engine repair, who has some basic information about engines, but no specific information.

I do a considerable amount of "research" on the web looking for helpful information. There is a lot of information out there if you can find it and you can apply it to your situation.

I am an X Marine and I have suffered my share of knocks and bruises. ONe thing that my training taught me is that I can do just about anything I set my mind to do. I don't always do it the easy way, but I always meet my objectives.

It may be that I will become the 6 wheeler "expert" in this area. Perhaps I can help someone else then.

Thanks

Steve

Top of pagePrevious messageNext messageBottom of pageLink to this message   By Attex Bob on Unrecorded Date: Edit

Hey there gunny!!! He he he he. Yes, you can just swap the jugs and pistons and heads. Most two strokes pin the rings so that won't be a problem. If you do this Steve make SURE YOU MARK EVERYTHING!!!! Make sure #1 piston goes in #1 jug, and so on. Make sure they go foward, and so on. You will be fine, just take your time, and you will get this thing running in no time!!!!
Good luck Steve.

Top of pagePrevious messageNext messageBottom of pageLink to this message   By schunn on Unrecorded Date: Edit

Hey Attex Bob:

I'm from the old corps. This current practice of defining your tactical mission and giving the troops the latitude to go in and devastate the opposing force is a new one to me. It makes me feel like we did not know what we were doing. (Vietnam) But to the contrary, a killing machine is not effective if the beaureaucrats tie your shoelaces together. One thing that Chesty taught me is to adapt and overcome whatever obstacle is in your path.

Getting back to motors--

I discovered how to get the jugs off the spare motor last night. So i have a spare block/piston/head assembly that I will do a head transplant on the motor in my attex. The spares pistons are smooth and clean, no scratches and better yet they fit well to the cylinders. The new motor should benefit from substantially increased compression values.

Maybe this weekend, I will pull the old jugs off the other motor and do the block transplant as an assembly.

Also, i found out that the magneto for the spare is hiding behind a flywheel that was just slid over the end of the crankshaft. the spare magneto, physically appears to be intact. I will try to transplant it also, if I can figure out how to remove the stator coils without destroying them.

I need to clean up the blocks to get them looking like bright metal. Any idea what i can clean them with?

And yes, I marked the orientation of the heads, blocks and pistons, including direction before I removed the spare stuff. I saw somewhere there is a reference mark that will indicate the intake side from the exhaust side of the piston. When I get the wrist pin circlips off maybe I will see them.

later

Steve

Top of pagePrevious messageNext messageBottom of pageLink to this message   By matt on Unrecorded Date: Edit

my max iv won't start . it was sitting for about 6 months now it only fires up with starter fluid but won't say running.

any help
matt

Top of pagePrevious messageNext messageBottom of pageLink to this message   By mike abbey on Unrecorded Date: Edit

brotherinlaw had same problem with terratiger,I found the needle was stuck in its seat.I guessing its wr or wd carb.We dont know how mechanily inclined you are,be carefull,1st does the fuel return line have gas in it did it flow whene engine ran on ether,if gas was moving fuel pump portion of carb is working.if not check fuel line coming in,check pulse line too for cracks or leaks.make sure gas can even get to carb.if you feel the need to remove carb turn it upside down to dissassemble clamp it or cradle it so it cant fall side ways there are three hair like springs in the last plate,MAN it will be the peices you loss if any.if the fuel was flowing there realy no need to seperate all the plates.seperate at 1st gasket and 2nd gasket.the needle and seat or on main body beside a plate with three flat head screws on it the lever has acurve on it,it moves the needle up/down leting fuel into carb section.If i was doing this I would go ahead and get rebuild kit first then take the carb apart you should get a good drawing of carb and the most critical part is to adjust art on needle to the correct hight[I think its .005 to.020 off the base of carb.but it could just a little gummed up a little cleaning might fix it.


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