Hard Starting B&S Intek 6.75hp

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So the new to me Ariens lawnmower I picked up earlier this season is becoming difficult to start when it gets up to operating temp. The guy I bought it from told me this, but it really wasn't a problem when I first started using it. It would take 3 good pulls after a shut off to get it to fire up, but it would just catch and slowly sputter up to normal operation. I pulled the valve cover and adjusted the valves to the wide end of the spec so that they wouldn't be tight and the problem seems to go away. During the summer, I really don't stop cutting once I start because I mulch, but now that leaves are falling I've been bagging and dumping them on the street. It now takes 5-6 good pulls to get it to catch and sputter to life. I checked the valves again and they are still right where I set them when cold. I haven't checked them hot, but might try that over the weekend to see if they need to be outside of the spec range to insure they aren't tight when hot. Anyone else have any tips or recommendations at what else I should be checking? The air filter was new this season, along with a fresh NGK plug. When cold, it has a good blue spark but only when pulled hard. When I try to start it when hot, I have to really tug to get it to turn over as fast as I can, otherwise no amount of pulling will get it to start. Once it does restart, it runs at 100% so I'm hesitant to think the coil is bad. I even tried priming it once when hot to see if it's a fuel issue, but had the same results. Thanks in advance.
 

threeputtpar

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Originally Posted By: Blaze
Does it use the "hot start" method or the priming bulb?
I'm not exactly sure what you're asking, but to start it when cold it's 3 presses of the primer and one tug and we're in business. It should start without priming when hot.
 
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I was recently watching a couple of donyboy73 videos on youtube and remember that the manual for the bigger B&S engines, they specify to set the valve clearance 1/4" past TDC. I think that your valves might still be a little loose.
 

threeputtpar

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Originally Posted By: jeepman3071
How does it run once it is started? Any sputtering or smoke? Does it seem to have decent power?
Once it starts and gets up to operating rpms, it has full power and cuts great. When I set and double checked the valves, I did go just past TDC like the Briggs manual says.
 
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I have a John Deere (Home Depot) JS63C push mower with a Briggs I think 6.5hp. Did the same thing. I'd pull like crazy when hot to restart. Bought a new coil for it and replaced. 4-5 years now, going strong and starting quick cold or hot. I also did change the plug again and went back to champion. There was something else in it prior.
 
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<span style="font-family: 'Verdana'">Give me the engine numbers so I can see what you got. I have all the illustrated parts lists for B&S on my computer and if I had the engine numbers, I could see which type of carburetor you have and everything else. Look on the engine and give me the Model, Type, and Code numbers.</span>
 
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Originally Posted By: threeputtpar
Originally Posted By: jeepman3071
How does it run once it is started? Any sputtering or smoke? Does it seem to have decent power?
Once it starts and gets up to operating rpms, it has full power and cuts great. When I set and double checked the valves, I did go just past TDC like the Briggs manual says.
I think it is your coil that is having a heat related failure. I've seen it on a few Briggs engines. They start fine cold but when warm they take a few more pulls, crank longer with electric start, or don't start at all until they cool down. The valve adjustment shouldn't be that much different on a hot vs. cold engine to impact starting, especially if you adjusted them to spec. My money is on the coil.
 

threeputtpar

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Thanks jeepman. I won't have time this weekend to [censored], but still have more leaves to clean up so will have time during the week to test out spark on a hot coil. Merkava - I will try to get the engine info if I can remember. Edit: Oops, that should have been assess. I missed the last s. tongue2
 
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I think coil assembly too. I have a intek 6.5 that was easy to start cold but impossible to start hot. Replaced coil and it was starting with one pull after that. Briggs coils seem to be a big item on ebay, maybe that says something. They go bad sometimes.
 
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Have you actually taken the top off and looked at the coil? It might be nestled in a glob of grass making it get very hot. Also, those sometimes leak a little out of the head gasket right onto the coil making it extra hot and not as effective.
 
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I would adjust your valves again, in the middle of the specs. Then put in a new spark plug gapped at .25 (should be Champion RC12YC). Check air filter to make sure it is clean/like new. If still having problems, it very well could be the coil.
 
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What you can do is run a Briggs & Stratton 19368 spark tester in series with the spark plug wire and spark plug. Look to see how bright the spark is while the engine is cold and compare that brightness to the spark when the engine is hot. You might not get any spark at all when the engine is hot.
 

threeputtpar

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Originally Posted By: jeepman3071
Originally Posted By: threeputtpar
Merkava - engine number 120602 0195 E1
Here is the coil you need: http://www.ebay.com/itm/NEW-BRIGGS-AND-S...=item1e7a18d021
That's a pretty good price, with free shipping. Thanks. So I used it last night to clean up the rest of the leaves for the season, and it was starting when hot with just one good pull. The only symptoms it still shows are a small pop when I tug the rope and then it slowly sputters to life. With the symptoms being so inconsistent, it sure looks like the coil might be the culprit. Being that the mowing season is all but over, I may just hold off until next year and pull it apart over the winter and give it a good cleaning and look over.
 

threeputtpar

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I think I have good news. My dad stopped over last night and I got to asking him what he thought about the hard starting mower. After a few questions, he asked how many times the engine turns over after releasing the dead man handle. I said that I had noticed that sometimes it seems that it will stop after 3 or 4 turns but other times it will go around quite a few more times. I've noticed that it has done this since I bought it, and the guy I got it from told me he has a hard time starting it when hot also. I haven't taken it apart yet, but using it one more time last night I paid close attention to it when I stopped to empty the bag. It appears dad was right, whenever it stops quickly it starts right back up and when it spins on for a while it will not start or start really hard. The darn thing is pulling in extra fuel while it spins around but the plug isn't firing therefore flooding it. The times when I thought to try the primer only made it worse. Never had this happen before on any machine. Hopefully, it just needs an adjustment of the flywheel brake or the dead man cable. There's still something to say for experience.
 

threeputtpar

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A final update for anyone that finds this thread via a Google search. Pulled the mower out this spring and still had the same starting issues, along with a new problem starting it when cold. I found the service manual for the engine online and discovered that the plug gap per the manual is only .020". I'd been running it at .030" according to other sources, but I think that may have been for L-head models and not for my OHV Intek. It starts first pull cold and hot now, so I think all is good. I did not end up replacing the coil.
 
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Yeah I didn't notice the thread was so old but I was going to come on here and recommend that you bump the spark gap down to .020 or .025 from .030. And to make sure and run the proper Champion RC12YC plug.
 
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