yamaha 225dx gas in bowl but will not start

[BigDave]

I bought a 1985 Yamaha 225dx last fall from a guy who cobbled it together. it ran when I bought it and after this weird Wisconsin winter it now refuses to start. I changed the oil got a new plug and cleaned the carb twice. it is getting spark and from what I can tell it has completion. when I had the carb off I shot a little starting fluid in and in one pull I roared to life. I am at a lose because when I hooked the carb back up and used the starting fluid again I would not sputter. and to further confuse things when I unscrew the drain valve gas comes out. I don't know if it is a vacuum problem or what anything is appreciated.
I hope I can get this damn thing running soon.

[ngunter2]

First off, new gas? Drain some into a clear bottle and make sure it is clear. Rusty old gas will not help. Have you done spark plug tested to see if you are running lean/rich or getting gas at all. have you put it together and tried to start it then checked the plug? Any gas on it? Is it drenched?

Any tests with feedback?

[BigDave]

thanks for the reply
the gas in it is about two weeks old and is ok. I pulled the rip cord 10 to 20 times pulled the plug and it only slightly smelled like gas. the next thing I'm going to replace is the o-ring on the carburetor that comes into contact with the manifold maybe its a vacuum problem. when I put my hand over the manifold with out the carb on I can feel a suction, but when I put the carb on there is little to nothing
thanks for the help and hopefully we can figure this out

[TxPowderCoater]

check and clean the jets, sounds like they have laquered up and clogged

[BigDave]

I had them sitting in a bath of carb cleaner over night and I used a air compressor to blow them off

[TxPowderCoater]

but the low jet is a waaaaay tiny orifice and it benefits from a # bit ran through it to de-scale. they have such a tiny hole that even the slightest bs in the way makes for a miserable starting critter.

[petedriver]

And while your at it put an inline fuel filter on it just for good measure.

[BigDave]

I got a inline filter on it now, but what would I use to clean the low jet with would I be wrong to use a peace of copper wire to pick around in it.
that's again for all the help but would a clogged low jet cause it now to even sputter?

[muthey]

Also in the carb bowl there is a hole that one brass rod goes in from the top at the bottom of that hole is the starter jet make sure that is not plugged

[ngunter2]

If it is a suction problem it would be VERY noticeable when you look at the o-ring. This was a problem we fixed on my three wheeler and it ran. It was pretty bad too. We sprayed cleaner around the gasket while it was running and it pretty much bogged. It probably isn't your problem. Change it anyway for it to run better when it gets going. And for the low jet the best thing to use is a drill bit just big enough to fit in it without catching the sides. It should be able to slide in and out very easily. You could try the wire but it probably is not as effective.
Next, from what I hear it all checks out. I would guess it is getting to little or too much gas. Did you do the test with the choke on or off? Do it with the choke off. So the plug had gas on it? Could you see that it was wet or dry? I would test this over and over again and if it is wet back your air screw out a half turn then retry until you get a dry plug so we know it is tuned in. Have you tried opening the throttle and pulling plus the choke...without the choke? I always opened my pull start wheeler up to start it. Try everything with the results and details then feed it back to us every little thing helps.

[barnett468]

Hello


As suggested by others your problem is most likely a simple carb issue but your replies to questions and results of tests suggested will get it figured out, not to worry.

Smelling your plug won’t tell much but it might give you a buzz for a few seconds. You must LOOK at it CLOSELY to see if it is damp. If it is dripping wet it of course will be obvious.

A single clogged jet would NOT prevent it from even “sputtering” [as you call it] when trying to start it providing the throttle was at least part way open while you were doing this.

Only a drill bit or a very stiff wire like one pulled from a wire wheel will help insure that any potential “lacquer” [as TxPowderCoater] called it or “fossilized junk will be cleaned out of a jet. Neither will damage the jet. However I have never seen anything harden in a jet in a carb on a bike that was running just 6 months ago or so. It takes MUCH longer than that for this to occur. I think it took the Dino’s a little longer than 6 months to fossilize too. Your carb cleaner SHOULD have worked but it won't hurt to recheck to be SURE.


The following is what I would do in addition to what has already been suggested.

Turn your gas off, drain the FLOAT BOWL gas into a clear narrow glass, what color is the gas, any debris, is there a small clear bubble at the bottom of the glass [water]? Rgunter’s gas inspection suggestion is helpful but my technique is a little more thorough.

Remove plug and lay on head and check spark and tell us what it is ie weak pale yellow or strong lite blue etc.

With a CLEAN [not black or crusty] plug and with gas still OFF, choke OFF and throttle fully OPEN, spray a SHORT burst of FLAMMABLE [not water based] carb cleaner [not WD40 etc] into carb, using the long narrow nozzle it comes with to do this.

Try to start using 1/4 throttle, if it does NOTHING you have other problems in addition to possible plugged jets guaranteed.


If you answer the following question it will help me and possibly others better understand your problem and offer more informed suggestions.

Did you ADD new gas to OLD gas or was tank DRY etc?

When you tested “suction” with the carb on and felt noticeably less than with the carb off did you have the throttle wide open or fully closed etc.?

Was it stored indoors or outdoors? Electronics don’t like water or condensation.

What color is your plug?

1. white
2. lite tan
3. dark tan
4. dry black
5. moist gooey black.

Even if your plug is 1-3 clean it well with a brush, if it is 4 or 5 trash it, don’t try to clean it.

[BigDave]

I will definitely pull the carb back off tonight and clean in again. the spark is strong and blue in color. the plug is brand new without any discoloration. gas tank was drained before the winter and new gas was added. when I try to use the pull start and throttle I am only able to pull for a short distance before is will not allow me to pull any further. it is stored in a garage out of the elements. there also is not any water in the gas you guys have been extremely helpful will try the suggested tonight or Friday.

[barnett468]

Hello


when I try to use the pull start and throttle I am only able to pull for a short distance before is will not allow me to pull any further.


This does not sound right, please explain in more detail. This typically happens when there is excess gas in a cylinder or it is getting gas but the plug is firing too far before tdc because ignition is too far advanced for some reason.

Check timing.

xxxxx

it is stored in a garage out of the elements. there also is not any water in the gas


There is no guarantee of that unless you look, the new gas can have water in it from the station, seen it several times. I would drain the bowl and look for the color, sediment and water it but it’s up to you.

Xxxx

I would also do my brake or carb clean test before taking carb apart because I’m going to suggest both these same tests again when if doesn’t run after you clean the carb. I would definitely take carb apart these tests done though.

[TxPowderCoater]

you can get # bits off of amazon for $3 a set. these are very tiny and all you do is pick out the correct one, clean the jet with it twisting drill bit in your finger tips and then re-install a happy jet. to use wire, your gonna have to find a small stranded speaker wire and hope the strands are thin enough and then stiff enough to work for what you want.
use the wire and air pressure to clean the air passages and such in the carb body and venturi area, make sure the small air jets in the venturi area are clean and unclogged as well.


I got a inline filter on it now, but what would I use to clean the low jet with would I be wrong to use a peace of copper wire to pick around in it.
that's again for all the help but would a clogged low jet cause it now to even sputter?

[BigDave]

ok thanks for all the help I will be trying all this, this weekend

[zappaz]

the best way ive found to clean a jet
with a single wire from any wire brush and my ol yamiesqua the lil jet will plug in a heart beat