Fire but no start!
 

Well im back! Forgive me for not hunting my issue down through all the discussions but I am getting a bit worked up, help me with some ideas please! My 125 gy6 talon was parked last season smoking and not wanting to start. I was/am bout ready to sell. Couple days ago pulled breather of and seen lots of fuel going thru carb. Pulled carb apart and ill be dampened the main jet and emulsifyer are missing!!! I have a 16 year old who I believe tried to fix it!! Bought new carb, intake and filter set. Adjusted valves and all I get is put, put, put while cranking! Wont grab and run or idle for that matter!! Any thoughts???

Did you change the old gas?

I did! Drained tank and put premium in. Oil smells alot like gas though! Kinda curious as to what kind of compression I should have. It seems to have some but when I rotated flywheel by hand is was awful easy.

New carb came with air screw set at about 2 1/4 turns out. I tried both directions and nothing. As it tries to fire it is puffing smoke still. If I try to give it any throttle it tries even less. Plug shows signs of fuel but not soaked.

for under $10 bucks I would change the oil, and do a compression test, remember to have the throttle wide open when doing a compression test you want to see at least 150psi.

Maybe try disconnecting the fuel from the carb and try it? If it starts and runs for a few seconds then you may just need to lower the float.

Oil smelling like gas could mean the float is set so high that it's just dumping fuel. BUT it could be from your kid taking out the jets on the old carb.

I did try regulating the fuel to carb to do as you say and no change. Im sure the main missing caused the excessive fuel in crank case also. After jman said it should have about 150 psi in cylinder I am really beginning to think I have a compression issue cuz this motor really rolls thru compression stroke quite easily. I didnt hold throttle open while I rolled it by hand but I would think it should have still appeared to have more than it does. Could all the fuel going inthere from previous carb had washed cylinder walls enough to lose all that compression? Would oil in cylinder bring it back?

After adjusting valves last season it was starting real easy and rode it quite alot. All of the sudden I noticed it started smoking like a two stroke and progressively began starting harder and then I find the main jet removed! Figured it was gonna be easy fix with new carb but not so!

By the way, I have a ball valve for my fuel supply to eliminate the vacuum style. Oh and another piece of info, on the side of my original card, the intake vacuum went to a small round cover which inside has a spring and diaphragm. Well I noticed new carb has this but the hole is not open its just solid. I took one from original carb off and the noticed diaphram was no good and tried to blow thru the hole, nothing. That one to seems closed or its plugged. Was gonna put on new carb but dont see the reason since it came blocked and no diaphram in it. So I blocked of the intake port. Could this cause a problem?

Can't remember what that diaphragm was for.

If not an accelerator pump, it might just be to lean out the mixture during engine braking.

One you tube video the guy said it was for adding more fuel when under heavy load but dont know!??

That might be right. Maybe when the vacuum drops it gets a pulse of fuel from that diaphragm, like an accelerator pump.

Just a thought, but because the cylinder lays horizontally to the crankcase, could it be sucking up that fuel soaked oil easily causing my seemingly rich condition? Or is that just another sign of weak rings if so?

Is the oil way over filled? Maybe from gas getting in there? If so that may be the reason it's smoking.

No its on stick where it belongs but it did use oil last season! Leaning toward just installing the BBK

Know anyone with a compression gauge? I would check that before I called it quits.

Yeah but not sure about an adapter for that peanut plug size! Are they readily available?

Good chance I wont give up as I am a mechanic but I have a car I wanna paint before snow flys here, haha!!

I meant before you gave up on the engine. Most compression gauges come with different size adapters.

Im gearing up to just buy the full kit that is on ebay and talked about here. Cheap enough price and I will get more power regardless. Sounds like the a12 cam is the one for me as I read its for lower ranger power as is what I would probably want around here. Seems nobody carries the 10mm adapter but I can order cheap enough for compression test but its time to just do whats best I think. I am gonna make one more attempt by draining thinned oil out of case and install new plug. I really love this buggy, its a good time!! I listed it on Craig's list but no one will give me what its worth im sure so I will just fix it and keep the fun for myself!! Thought maybe asking the question here may spark someone with a similar problem as i was ready to ride once i received my carb but no such luck!! But i appreciate all the suggestions its what i was looking for and it keeps me thinkin!!!

I dont believe in giving up on any engine!! Just fix them and let the mods begin!!

if your engine oil has gas mixed with it that would cause it to burn more easy and make the engine smoke also. its not good for the engine at all.

Will let you know what happens!!

Latest update! Changed oil and plug. It tried to start about 3x and then just cranked. Checked plug and definitely getting fuel. Checked spark and it is very faint with an occasional brighter one!! Do these have big bright spark?? This wasnt even close to what I normally see from lawn tractor or other.

In fact I could barely see the majority of it!

should be brighter

Sound like I need new coil and wire then maybe! Or dirty stator??

I would make sure the spark plug wire is screwed all the way into the coil and the boot. I would also make sure the battery is fully charged and all the wires are tight.

Check for shorts and bad grounds.

Gonna be hot day here in michigan so gonna spend it fishing and on pontoon. I did check connections but didnt verify a good ground. Had jumpers on buggy whole time I've been playing with this problem. Gonna.take break from it today and then check grounds later.probably order some new ignition stuff for giggles anyway.

:evil:
i just breezed through this so forgive me if i missed it but ....i saw someone ask about doing a compression check but i didnt see if you had done one. i know the common three places to start is air, fuel, fire but w/out compression all of those wont really help. i wouldnt spend another penny on it except for a compression tester to see where you're at. no need to start buying parts until you've nailed down the problem. that tool is money well spent. cant tell you how many times ive worked on customers stuff and spent an extra hr on it because i didnt grab my comp tester. so how i check the basic 3 and if that's there compression next. if it's smoking that would be the 1st sign anyhow.

I agree, I would like to know myself where its at. But this very weak spark now has me concerned also. It may have a couple problems I guess but im gonna have to get this 10mm adapter.

schoop, Harbor freight has a good compression tester for a good price. after a 20% off coupon ,I think I paid like $20 for mine. it has the 10mm adapter and others included. very nice kit for the price. I don't have the item number right at the moment, I will get it when I go down to my man cave in a little while.

Ok here's the latest on my spark issue that is very faint. Firstly, no disrespect at all to zman but I dont have adapter yet. Will still b checking that. I ran thru the buggy depot ignition test procedure and found trigger sending signal to cdi but no AC voltage out to coil. It says at the very least they have seen 18vAC operate the coil but I have none. Im gonna buy the performance set. What gets me is that I have even faint spark!!

Still have plans to upgrade cylinder regardless, just wanted to ride it a little before it gets cold and get back to working on my project car.

To any newbies on here, I wanna say, listen to these guys on here and dont overlook anything!! Since joining this site I have realized that valve adjustment is critical and should never be ignored and now I've learned that the free information supplied by you all is priceless!!! Mine isn't running yet but im fixing all my weak points and the parts for these motors couldn't be cheaper to build whatever it is you want!!

hey schoop the item # on that compression test kit from Harbor Freight is 66216. it is well worth the money. and yes it does have the adapter to fit gy6 engines included.

Cool! I can get it thru the catalog at work! Thanks a bunch!!

Well the ignition kit made it run!! Woohoo! It actually spins cookies now!!! But....still smokes....cant wait to do the upgrade!!