21hp I/C Twin Hard Start and Surging

[cruzenmike]

Up north for the weekend and my cousin's Craftsman LT1000 won't start without starting fluid. Had to spray fluid directly into the carb repeatedly for about a minute before it ran on its own. After it started running on its own it was surging really bad. If I pulled the choke about half way out it would smooth out and run without surging. The mower is quite old and desperately needs a tune-up which I plan to do, but as for he starting and running issues, what could the problem be? I am thinking that the carb might just need a rebuild but am lost. My cousin told me to just buy whatever parts it needs and get it back up and running so I just want to get an idea of what I will need.

Engine Info: 461707-0145-E3

Thank you.

Mike

 

[Scrubcadet10]

Carb clean and rebuild...
Spray out all the jets, remove and. Clean them.
Good videos on YouTube for the Opposed twin carbs.

 

[Scrubcadet10]

You should be able to type the numbers into any online parts source...Jack's small engines,Proparts direct or parts tree

 

[Fish]

On the lower side of the carb is a brass nut/plug. Remove it and watch the fuel dribble out a little. Inside there is a jet that can be removed using an allen head wrench, remove it.
Then crank the engine a little and fuel should pulse out.
Clean the jet out thoroughly, and reassemble everything.
Then start her up and see how she runs.

 

[cruzenmike]

So, here is an update:

I went up to my cousin's cottage this past weekend and worked on the mower. I started a tuneup on the engine including new OEM plugs, gapped and properly secured, with anti-seize and di-electric grease. Also, the oil was really dirty so I flushed it twice and topped off with SAE30. I replaced the air cleaner and fuel filter. While changing the fuel filter I found that the fuel line from the filter to the carburetor was dry rotted and in fact had a hole in it. Thinking that this might have been the answer to my problems, I went ahead and replaced that section of fuel line. WELL, when all was finished, the mower was still running the same, surging at idle and even slightly at full throttle. Pulling the choke out smooths out the engine and it runs just fine that way. I tried to adjust the carburetor from the mower manual but the carb lacks the adjustment screw for the air/fuel mixture that the manual references.

The surging has me thinking that there is something going on with the governor, but I have yet to rebuild or replace the carb. I am thinking that I will just throw a new carb on it and hopefully it will work.

My question is, the governor on this engine is not like I am used to on the newer v-twin engines. I don't even know where to begin on adjusting this type of governor, nor am I sure that it is the problem.

What are your thoughts?

 

[bertsmobile1]

surging is nearly always a lean burning condition
So not enough fuel from the carb or air leaking after the carb.

 

[Scrubcadet10]

pulling the choke out indicates the engine is running lean So it could be air leaking after the carburetor through the intake manifold(there are two gaskets, 1 on each head/side of the engine...or the carb is still dirty.

governor static adjustment:
all linkage must be installed to make adjustment, loosen the governor lever bolt and but (7/16" if i remember right) push on the governor level until the throttle is wide open. hold the lever in this position, Now rotate the governor shaft COUNTERCLOCKWISE, as far as it will go, hold the lever in the WIDE open throttle position and the governor shaft in the clockwise position and tighten the nut up. (100 inch pounds torque value).

 

[cruzenmike]

pulling the choke out indicates the engine is running lean So it could be air leaking after the carburetor through the intake manifold(there are two gaskets, 1 on each head/side of the engine...or the carb is still dirty.

governor static adjustment:
all linkage must be installed to make adjustment, loosen the governor lever bolt and but (7/16" if i remember right) push on the governor level until the throttle is wide open. hold the lever in this position, Now rotate the governor shaft COUNTERCLOCKWISE, as far as it will go, hold the lever in the WIDE open throttle position and the governor shaft in the clockwise position and tighten the nut up. (100 inch pounds torque value).

Thanks. I am going to order up new intake gaskets as well to throw on with the new carb. If that doesn't work I will try the static governor adjustment. I have a hundred dollar budget to fix the machine and with all the parts i have purchased I am only about $70 in. Hopefully there's a little left for me to pocket!

 

[Scrubcadet10]

I also forgot to mention, there are two gaskets where the manifold bolts to the carb with a thick spacer. Could be leaking there too.
I use WD 40 in a trigger sprayer and spray around any gaskets while the engine is running, and look for the engine to blow white smoke or rpm's change.

 

[upupandaway]

What are your thoughts?

From personal experience, I agree with Fish and would bet cleaning out the bowl and the metering screw at the bottom of the carb bowl will fix your problem. I swear 99% of the time i find a mower that won't start(with carb problems) or won't stay running, this is the fix.
Check the easy stuff first. Don't take it apart and replace parts as I would think parts going bad, seals breaking would not likely do so from it sitting around (as it sounds from fuel hose rot and it hunting).