Carburetor on Craftsman / Tec 2.5 hp H30

D

Dadrider

#1
#1
Horizontal shaft H 35426T Diaphragm carb going on a vertical intake adapter to the block

This engine is mounted on a non slanted Craftsman Edger, 2.5 hp.

I rebuilt the carb a year or so ago. It ran good but the 2 adjustment needles are real sensitive as in 1/4 to 3/8 turn from running to dead.

It has run good for the first 3 or 4 edges that I’ve used it this year. It ran ok last year after the carb rebuild. Now it starts and runs maybe a minute shuts down with no restart. Spark is good.
I am almost ready to put a 79cc predator on it but will have to redrill the mount.

The reason I think it’s the carby is that it starts, and runs until I load it up to turn the edger blade. Now it bogs, and stalls with no restart…..

Is there a bolt on good replacement carb that works with the gov and throttle linkage?
I am a 55 hr a week mechanic. I am about done with putting time on this engine every other weekend to do a 10 to 15 min edge job on my sidewalk.
in its defense when it runs, it runs very well. I am just ready for good reliability week in and week out.
Ok I am done ranting….

Anyone have an idea?

Dadrider
 
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D

Dadrider

#3
#3
desert rat said:
Main jet is plugged would be my guess. The other would be an issue with the governor adjustment. Don't run E fuel.
https://www.pure-gas.org/index.jsp?stateprov=LA
Click to expand...
I try to pretty much run old school 100% gasoline in it.

Being a diaphragm carb is the drill to pull the diaphragm off the carb, pull the low speed and high speed adj screw and use like 10 psi compressed air? I don’t have the carb or parts breakdown in front of me. Still at work…

Thanks
 
RobertC

RobertC

#4
#4
I've only rebuilt one diaphragm carb @Dadrider ...and it was last year. It too was from an H30 Craftsman edger. And is destined for my sons Bonanza mb250.

But yes, those steps sound reasonable (I used spray carb cleaner on mine, and no air.)

I'd give that a try...and if that doesn't work, I suggest getting a rebuild kit, to get new rubber o-rings, and while you're at it, go ahead and replace the diaphragm.

Anyone with more experience on these carbs, please chime in.

Keep us posted on your progress.
 
D

Dadrider

#5
#5
Update guys:

I pulled the carb, pulled the diaphragm and the valve that screws onto the carb body along with the spring

Removed both needles

Sprayed carb cleaner 2 or 3 times and reassemble carb and then reassemble to the intake.

Also cleaned flywheel magnet and set air gap to .010

Check valve lash Int is a .004 Exhaust is at a loose .008

Cleaned top of piston around valves and decarbonize the head. Reassemble and torque the head.
Dump gas tank and refill with fresh.

Took about 20 pulls to fire. Adjust right needle to run clean. Left needle does little if any to affect the way the engine runs.

When it runs it runs well and carry’s a good to heavy load.
Shut it off hot and it took 5 pulls to restart

I let it sit for 3 hours, It took took 15 to 20 pulls to start.

I pulled the air filter. Gasoline is dripping out of the carb inlet.

Do I need to put another kit in it? The Left needle is not responsive. Do I need to soak it to clear that left needle passage?

Do I need to get another carb?

Any ideas?
72994A83-394D-4DCC-B0CB-7DCB93BB8DE5.jpeg 71573F01-DC84-4882-BE57-59004584772E.jpeg
 
D

Dadrider

#13
#13
Dadrider said:
Thank you. I am going by Napa today or tomorrow to order it.
Click to expand...
Napa no longer stocks at least via online, I have a kit, the manifold gaskets, and air filter on the way through another source. I am going to pull the Welch plugs, soak the body briefly in white vinegar and have it ready when the parts arrive.
 
D

Dadrider

#15
#15
The dripping fuel was caused by the needle housing (the brass piece) either loosened or I didn’t tighten it enough after the cleaning.

Engine started on 2nd pull on choke, moved choke to run. Made little adjustments on low and high speed needles. Both needles are responsive now.
Ran the edger on my sidewalks. When I finished I did idle it on the idle screw. Shut it off and let it sit 5 min. It starts right back up on the choke. Then move the choke to run and it runs fine.

Did a restart after 3 min, an hour and 3 hours. It starts just fine now…

Thanks for the video, and the advice. I got a rebuild kit and intake gaskets now for down the road.
I won’t be needing a predator now….

Dadrider
 
D

Dadrider

#16
#16
Something I did last year to the little Tec, when I repaired the governor.

Something I did to the bowl areas and ports of my 4 stroke dirt bikes….

I slightly cleaned up the exhaust port under the valve seat bowl out to the end of the port

I did a little of the same to the intake, but not as much to keep the velocity up.

I did open up the end flanges ports of the strange looking intake manifold at each end, but just a little. A light cleanup.I don’t thing it did much if anything

I did unshroud the valves a little and relieved the top of the block slightly, More like a unshroud and a taper to a little above where the top ring stops in the cylinder

I do not think I gained HP. I didn’t really expect to as for one thing I kept the governor in place. So peak RPM I am running is OEM which for me is fine.

I do see and believe I am maintaining torque under a heavy (heavier) load.

I make a pretty deep trench when I edge…..

Before When I would hit a earthy spot and the engine speed decreased a few hundred to several hundred rpm. The little 2.5 hp holds rpm in those similar areas that work the engine harder.

So I am not claiming a HP or Torque gain. I do think it is maintaining torque better at rated RPM than OEM was.
I am keeping in mind not to work it too hard, as I realize it has some years on it with a stock rod and an unpressurized lubrication set up….

Thanks again for the help and video. Next time something breaks I will be back, but I do look at new posts every couple of days…
 
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Dadrider

#19
#19
When I was a kid around 7 my folks gave me a 3rd hand min with a 3 hp Clinton white shroud. Primer bulb on the side of the carb.

Ran it into the ground, my dad and a friend rebuilt it and it made the same whopping could not pull a sick prostitute out of a bed power..

I think this 2.5 Tec made more torque….

May of 1969 I bought a Sears Roper 5 hp Large shroud 2 speed mini.

pulled the governor and ran it till it threw a rod 9 months later. Dad repaired the block with Devon, polished the crank and a new rod.

Ran it until it threw the 2nd Rod and later moved on to a 72 Suzuki TS 90J.

But that 2 speed was a real piece of work. What a real marvel….. In every negative way.

I think Sears / Roper made that same Tangerine / springer fork and shock mini with a TC setup

At the time Torque Converters we’re just coming to market. And they didn’t have a great stigma at least in my crowd.

I would do a Roper with a TC and something on the order of 6 to 7 hp…
 
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