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8243 Starting Problem

4828 Views 8 Replies 5 Participants Last post by  AMSOIL
I am a new member and this is my first post although I have been getting lots of good info here for the past few months. I got bit by the Lawn Boy bug a few months ago, and I am having lots of fun with the little green monsters.

I need some help with a 8243AE. I aquired it along with two others a few weeks ago from an estate. The starter and battery were shot, so I added a recoil and converted it over to pull start. The problem is that is is very hard to start. This model has a Walbro carb without a primer -handle mounted choke only. I can pull all day and it won't fire. If I give it a shot of starting fluid it starts right and runs fairly well. I have pulled the carb apart and cleaned it. I have played around with the altitude adjustment screw with no imporvement. The lower crank seal is dry, so I don't think that is the problem. It does surge a little at low throttle, so it may be a bit lean, but there are no adjustments other than rejetting?

I have another 8243 pull start, and this one has a Wlabro carb with a primer. It starts easliy. Is my problem the lack of a primer because it was an electric start model, or am I missing something here? Any advice would be appreciated.
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Welcome to the forum from another Mark that owns a Chevy. ;)

Can you see if the choke is closing proper on it? Maybe a cable adjustment? Might just be some gum in the carb causing it to be too lean to start even with choke.
Ditto on checking the choke operation. If that appears to be proper, I would run some SeaFoam thru the tank. I'm guessing there are some passages that are a bit gummed up. Also, is the spark plug new? How about the coil adjustment? Starter fluid is a bit more volatile and will explode easier than gasoline, so you need to make sure everything is in good shape.
Thanks for the advice guys. The choke appears properly adjusted and is closing fully. The coil is properly spaced - I used a business card which seems to work well as it has good blue spark with a new plug. I'll try running a little SeaFoam through the machine. I've had the carb off twice and it seems clean. I couldn't figure out how to remove the main jet on this Walbro LMR carb for cleaning as it looks to be pressed in. How do you get it out? Also, I think I will try swapping the carb from my other 8243 to see what results I get.
I would not try to remove the jet. Just use some SeaFoam and maybe some spray cleaner to clean ALL the passages and orifices. Also, check the float level. Want to make sure that you have a full supply of fuel in the carb. Sounds like you are covering all the bases.
I would also suggest a good quality synthetic oil at the manufacturers recommended ratio (Lubricant makers, not mowers). I am presently using Amsoil in my 2 cycle machines. I mix it at approx 50:1, running it in all my mowers, trimmers, blowers, snowblower, etc.

Here is a paid advertiser on a sister site that sells Amsoil products. I would not hesitate to use their synthetic 4 cycle oil, either, in any of my equipment. If any of you decide to purchase from this fine businessman, please mention that you heard of his business from the tractor forum.

AMSOIL - Don's Synthetic Lubes

He will also gladly answer any questions that you may have.
Here's an update. On Saturday afternoon I swapped out the carb from my other 8243 and got it going on the first pull, but it was running very rich. Th original carb is a Walbro LMR1 and the one I installed is a LMR3 with a primer. I recleaned the original carb and reinstalled it - got it going and ran some Sea Foam through it. It seemed to run well and was easy to restart. I let it sit overnight and tried it again on Sunday, and once again could not get it going on its own.

Last week I picked up a NOS Lawnboy cold start enhancer kit on ebay which is essentially a primer bulb and bracket with a different carb bowl bolt with a fitting for the primer hose out the bottom. I installed this kit, pushed the primer bulb three times, and had it running on the second pull.

I will continue to run Sea Foam in the tank for awhile and see if I can start it sucessfully without priming. If you don't succeed the first time, just add more parts!
Sounds like you found a solution, but I wonder if a new needle and seat would have fixed it? Anyway, if you run into this problem again, check that. Another tip is to always shut the fuel off when you're done using it.
As a Member i would like to be the Technical Voice on Amsoil products. I am a Senior distributor servicing the US and Canada. As a way of paying it forward these are available at Wholesale Prices with NO membership fees or minimums. Whatever you use and your happy, stick with it but if you want a better product with better performance and less maintenance consider what BRAD uses. Your questions or concerns are welcomed.
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