Riding Mower Saga - Need Help


Old 05-06-06, 09:08 AM
Thread Starter
Join Date: May 2006
Posts: 2
Riding Mower Saga - Need Help

Hi everyone, first of all just wanted to say great site, it's been a lot of help to me so far. This is probably going to be a bit long-winded but I'm trying to be as thorough as possible so that hopefully someone can help me out.

Now on to my saga... about a week ago I bought a used riding mower. Specifics on the mower/engine are:


Dynamark 12/38
Model = C3812010
Code = 1339


Briggs & Stratton 12HP "Synchro-Balanced"
Model = 282707
Type = 0110-01
Code = 91101411

Ok so, second day I had it, took it out for a quick run maybe 30 minutes... no problems.

Next day, mowed for about an hour and then big poof of white smoke, wouldn't start.

So, I read on here and learned alot of things, then went to work on the old dog. It needed new spark plugs, new air filter, and also I think there was some gas in the oil. So list of repairs so far:

- Replaced spark plug
- Replaced air filter.

After this, it would run, but then would die after about 5-10 minutes. If I waited about an hour, it would run again for 5-10 minutes then die. More research on here, more repairs.

- Replaced all fuel line, fuel filter, installed gas cut-off switch, checked gas tank for any debris etc (none), made sure vent hole in gas cap wasn't blocked etc (wasn't), made sure using fresh gas.

- Took the carb/air filter assembly off, took it all apart, cleaned liberally with carb cleaner, made sure float still "floats" (it does), made sure needle is back where it needs to be/no blockage (both fine). Let the carb dry out, got 99% of any gunk off of it anywhere near it.

- Reassembled carb/air filter etc, got it all back on, everything where it needs to go.

- Completely drained oil (let it drain while working on carb), refilled with oil (10w-30 "john deere" oil for riding mowers).

Ok so, at this point I put humpty back together, fire it up, and it runs great.... for about a minute. Then I heard a sound which immediately made me realize what an idiot I can be.

The ensuing grinding/squeeling sound made me realize that when I added the oil back in, I had stuck in my head "8 oz", b/c on the dipstick it says from "add" to "full" takes 8 oz. Well, sure but obviously when it's completely drained it needs more.

So, at this point I figured I've blown the engine. Back on here, more research, try some more things.

Started taking the engine apart, got to where I could dis-engage the starter gear and was thankfully able to rotate the (flywheel?) by hand. Turned it by hand for several rotations, watched the one big and 2 small (pistons?) go in and out, figure ok maybe I managed to not totally mangle the engine.

Put humpy together again... in the process I over-cranked one of the 8 bolts on the (block?)... the part on the front where the spark plug goes in etc. I'm not a mechanical genius but, I imagine that probably needs to be replaced sometime soon, cause it will probably make me lose compression etc, possibly cause more problems down the road ?

Anyhow, that's not my main problem right now (I dont think).

So, after all that, ran it for about an hour last night, ran great, no sputtering, no problems, feeling pretty good about it, aside from I need to get the broken bolt fixed.

Go out this morning to finish up the yard (big yard btw(, and it wont turn over. [email protected]#$%%

Take the engine covers etc off again to get to the starter gear. Could see that, when I try to crank it, the starter gear kicks it forward maybe 2 notches each time. Hmm. Was going to try the manual fly-wheel rotation thing again, but noticed that if i clicked the starter on/off, it would get to some points of the big (flywheel?) gear where it would spin a few inches.

So my second suspicion/issue is that there is probably something warped/rubbing/bent somewhere in the flywheel area.
Also, it was about 20 degrees colder this am that it has been recently.

Anyhow, after a few minutes of this, I let it sit for about an hour. Went back out, it had warmed up outside some, and lo and behold it was cranking around.

So now this brings me to my current biggest issue. Now when it cranks, it's spitting gas out of the carb all over the place. It's spitting up into the air filter, and also out the muffler, out the side, etc.

Not sure if it's actually going through the engine into the muffler, or just dripping out of the carb into it. (The muffler is sortof right below the carb).

So, now my suspicion # 3 is that even though I took apart/cleaned/reassembled the carb, it probably still needs some new parts/rebuilding/replacing.

I noticed when I took it apart, that even though the needle went into its house just fine and snug, at the bottom, where there's a little groove to sit in the float, it seemed to be too much of a gap. But then again maybe that's just how it's made. There were no extra parts or anything that were flopping around etc.

Also I noticed on the carb, the gasket between the bowl and the rest of it looked a little suspect, but at that hour I didn't have much recourse but to re-use it.

Sooo... that's my story and I'm sticking to it. Like I said from what I've read etc it seems that some more carb work is in order.

If any of you much folks on here that are much more knowledgeable than I care to offer any advice/opinions I would definitely appreciate it.

Thanks for reading my novel here haha, and also if I do need a new carb or a rebuild kit, where do I go about getting one of those ? I'm assuming I'd have to order it ?

Thanks again for any help you can provide.

Sponsored Links
Old 05-06-06, 09:57 AM
puey61's Avatar
Join Date: Apr 2004
Location: Upstate New York
Posts: 3,224
Well, where do I begin? The lack of oil and the noise you encountered is something you need to be concerned with. I'd wonder if the engine has internal damage as a result and you wouldn't know without tearing it apart and inspecting such. The head bolt threads you stripped is another concern. Even just one bolt threads stripped will cause the head gasket to blow out. These can be repaired with a Re-Coil or Heli-Coil kit. The fuel weeping trouble is likely caused by a leaking inlet needle and possibly the mating seat. I'd suggest servicing the carburetor with a Briggs kit, part number 497481, provided the carburetor has one of the following LMT numbers stamped into it: 63,65 or 66 - which your should, by the way. Furthermore, I highly recommend buying the service manual for this engine series, part number 270962. Anything you need for this, you should find a local Briggs dealer. Go to their website and do a dealer search based on your zip code.
Old 05-07-06, 11:59 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,814
And chances are there's oil in the gas again, so drain and refill (with proper amount ) after you get the carb fixed.
Old 05-20-06, 10:18 AM
Thread Starter
Join Date: May 2006
Posts: 2
One more question

Thanks for the help guys,

I ordered a carb overhaul kit from a local dealer, it (finally) got here the other day, so I got the carb all happy with it's new parts, drained/changed the oil, put humpty back together again.

After a little hesitation, it started up, so I gave it a quick lap around the yard once just to see, ran pretty good etc, so brought it back in, shut it off, and noticed a lot of smoke was blowing out of the muffler and also the engine block.

I mentioned before about one of the head bolts breaking off... the smoke was coming out from that area, so I figure obviously it's related.

So, went down to the hardware store, was lucky enough to find pretty much the exact same bolt for it, was able to get the other one out with too much trouble... got the new bolt in place, humpty back together again... and now it doesn't want to start again.

I'm almost positive there's oil in the gas again, based on how non-thick it is, plus the smoking from earlier.

So finally that leads me to my question... there's no leaking or excess gas anywhere around the carb anymore, so I was assuming that it was fixed... but if there's gas still getting in the oil, maybe I'm wrong ?

Also was wondering if running it for a few minutes with that bolt missing might have somehow caused it to pull in too much gas ?

Any thoughts would be appreciated, thanks again for all the help so far.


Last edited by alfa_diablo; 05-20-06 at 10:28 AM.
Old 05-20-06, 11:31 AM
Join Date: May 2006
Location: Iowa!!!!!
Posts: 3,728

Back up to the smoke issue. Is it black or bluish white? Black would be too rich a fuel air mixture or weak spark, bluish white would be oil burning.

For the rich mixture, look for carb settings, or leaking float needle.

For the oil burning, think in terms of piston ring/cylinder damage from your oil changing issue. Start with compression check. If its OK, recheck your oil level to see if you have overfilled the crankcase.

Hope this helps
Old 05-20-06, 11:23 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,814
You can generally smell the oil and detect gas in it.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes