| Author | Message | ||
     Thumper74 |
I've got a Simplicity 24" dual stage snow blower with a Tecumseh H70 engine (float style carb) A few days ago, it was surging. I took the carb apart and it was pretty gummed up, but lost the float linkage... I got a full rebuild kit and rebuild the carb. I made sure to remove the welch plugs, completely disassemble the carb and blew out every single passage. I put it back together, resetting the float to the correct height. I reset the idle and fast mixture screws to the correct settings per the service manual. Changing the idle adjustment screw doesn't seem to help, nor does the choke or engine speed controls. No spare parts were left over. New plug. Good spark. I noticed some funk in the tank, so flushed it and ran a new fuel line. The vacuum line to the primer bulb tore when I removed the carb, so I replaced that too. Now, it will only start with the primer being used or with starter fluid. If you do not use the primer or the starting fluid, it won't think of starting. | ||
| Hootowl |
I don't think I understand the problem. Aren't you supposed to use the priming bulb before you start it? Or do you mean even when warm you have to prime it? | ||
| Thumper74 |
If I use the primer(or starter fluid), it starts, but stalls immediately. If I don't use the primer (or starter fluid, it won't start. | ||
| Blake |
Make sure float needle is free, not sticking. Look for a tear in the intake boot if it has one, or other intake tract air leak. Had the same issue with a mower engine this past Summer. Found a tear in the intake boot between airbox and carb. | ||
| Thumper74 |
No air box, most snow blowers run open carbs for whatever reason. No carb boot to head either, uses a base gasket, that was reused, but in good condition. Considering buying one tomorrow... It's hard to check for a vacuum leak when it's not running... | ||
| Hughlysses |
I second checking the needle for sticking. Try tapping the carburetor with a screwdriver handle to loosen the float/needle and see if that gets the fuel flowing. | ||
| Spdrxb |
Will it run with fuel cap off? | ||
| Dalton_gang |
"Will it run with fuel cap off?" +1 The vent may be clogged. | ||
| Thumper74 |
First thing I did was take the fuel cap off | ||
| Spdrxb |
OK just trying to cover some dumb questions first. Did you use same diameter replacement hose, and route it same way as original? If yes then + to above needle is stuck or not opening. Matbe jet is still clogged. (Message edited by spdrxb on December 10, 2010) | ||
| Thumper74 |
Same ID fuel line, routed in same manner. It's perched precariously between the hot engine fins, in a bracket, next to a flywheel... But yeah, same exact route. I hosed the jet out with carb cleaner and compressed air, then carb cleaner again. I confirmed air coming out of each passage when blown through with the compressed air. | ||
| Spdrxb |
OK is there a drain on the bottom of carb fuel bowl? If yes pull it. you will at least know fuel is filling bowl. If fuel comes out, and everything in there is placed in its proper home it should run. | ||
| Thumper74 |
There isn't a drain per se, but there's the bowl nut, I can loosen that to drain it. But first, I'll tap the bowl and see if the needle is stuck... | ||
| Blake |
The bowl nut should also be a drain, just unscrew it partially and it should have a hole that will allow the bowl to drain without removing it entirely. You should be able to feel the needle sticking if you remove the bowl and actuate the float by hand. You may have to get a look at it to see if it even drops at all. | ||
| Thumper74 |
Got home, hit the primer bulb a couple times, set it to full choke, set the throttle to WOT and it fired up in one pull, but stalled after about 30 seconds. I wonder if the bowl wasn't full when I had tried to start it earlier since it was right after hooking the carb up.e It started again, but as I tried to idle it down from WOT, it stalled. I tried this multiple times and it stalls if it's not at WOT... | ||
| Xbjelly9s |
Does it have a petcock on the fuel tank? If the fuel was gummed up in the tank it may be stopped up or letting a limited flow of fuel through. | ||
| Just_ziptab |
Sounds like you did everything correctly. Carburetor is a French word that means : Don't foock with it". My V-twin garden tractor started acting up. WILL not run unless it has a wee bit of choke. Too much and it floods,none and it won't run. Pilot jet? Torn into it and found NOTHING..even mostly spotless inside. Blew it all out with Brake-Kleen and then air,assembled with all the old gaskets...runs fine again | ||
| Swampy |
Sounds like you have a main or primary jet plugged. Is there a main jet adjustment screw? Is there an idle air adjustment screw? You say it will not run with out the choke on? Annnd you say everything else is groovy? Good Luck | ||
| Sifo |
Does it have one of those diaphragm fuel pumps? I've heard of bad diaphragms being installed from rebuild kits before. You would need to check with a vacuum pump and gauge to check it though. | ||
| Aesquire |
Idle jet. If it runs at WOT, that means the main jets flows some. Remove the float bowl, and spray carb cleaner in all the holes under the carb. ( with eye protection, please ) Be aware that what you spray in should go somewhere...probably the throat of the carb. ( a manual will tell you what's what ) That's where the idle circuit should go. | ||
| Mr_grumpy |
What's the plug like? | ||
| Thumper74 |
I was tinkering with it this morning... It had a backfire when the choke was closed and I saw smoke coming from the base gasket. That was why it wasn't running well. I fixed that and it fired right up. I was able to adjust the main jet and then the throttle actually worked, so I idled it down and actually adjusted the idle mixture. It was pretty frustrating... | ||
| Gentleman_jon |
In other words, the carb was not tightened down properly, so there was an air leak at the base of the carb. You then tightened it down so the gasket sealed the joint between the carb and the motor and stopped an overly lean condition. Zat right? Or was it a different gasket? | ||
| Thumper74 |
The gasket wasn't torn when I removed it, so I decided not to get another one. I went back to the shop and got another base gasket. Though, admittedly, I have done that one before... Spending the extra $2.oo would have saved me a ton of headache | ||
| Ourdee |
WooHoo happy ending. | ||
| Iamike |
Boy I'm glad my 25 yr-old Sears snowblower started this weekend. We only got about 4-6 inches but the 35mph winds sure wipped it around. I'm thinking retirement further south sounds better all the time. | ||
| Natexlh1000 |
I know what the deal is. Those carbs have a central screw holding them on. They are round but part of the bowl is lower. Make sure the low part is allowing the float to drop. The shorter side of the float bowl is where the float pivot lives. I had to learn this the hard way  If you line up the short side of the bowl wrong, it keeps the float up and no juice gets in! | ||
| Thumper74 |
I learned that lesson on my old Toro... Stupid float. I ran it hard for about an hour and a half this morning and it's a beast! It did 5" of snow in 1/8 mile of sidewalk and 5 of my older neighbors driveways. | ||
| Natexlh1000 |
So it was just a bad gasket? My big Dr. House moment didn't work out? I'm glad you fixed it up though |
