Briggs opposed twin engine

tom3

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When those bass fishers run out of beer they need to get to shore quick!
 

SamB

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I've have a 422707 on my GT. '89 year. Keeps on chugging. A little fuel thirsty. You do have to re-build the fuel pump on carb every 3-4 years. But now - they have AM carbs for ~$30. I'd get another Opp Twin in a heartbeat.
I had a no start issue with the Twin 2 after it was up to running temperure after mowing for a half hour or so. It looked to me that the spark wasn't as hot as I thought it should be,as no spark that I could see. After it cooled overnight it fired right up,no problem. I mowed a bit and restarted it several times with no issues,started every time. I think this is a 1995 engine according to the ID tag. I am wondering if there is a upgrade hotter magneto for this engine. I know there is a ton of good knowledge here,so this is the best place to ask. TIA!
 

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Fish

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As I said in the previous post,2 different Intek AVS 17.5 singles have failed me,or should I broke themselves(and me,too)!
a couple of years ago,the first one ,for no good reason,snapped the head off a valve right above the stem and the head punched right through the piston. I bought a new Intek 17.5 AVS and put it on the Snapper 33" Extra Tough.
The second Intek 17.5,on my Husqvarna Z42175 zero turn,starting making unnatural rattling noises(death rattle?) so I shut it down,checked the oil. That was OK,so as I was in the far side of the yard,I started it back up and the rattle was back with a vengeance. I quickly shut it down again and towed it to the garage and removed the engine. When I removed the sump part of the case I saw one of the arms that move the AVS weights had broken. Since I mow a much larger area with the zero turn,the almost new Intek got transplanted to the zero turn and the Snapper got parked,engine-less. Till now.
Both of these engines were well maintained,regular oil and air filter changes,using good oil and having never messing with the governor,ran at the factory rpm settings. Both times,the engines were running just as fine as could be....till they instantly weren't.
Were you using 10w40?
 

Scrubcadet10

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I had a no start issue with the Twin 2 after it was up to running temperure after mowing for a half hour or so. It looked to me that the spark wasn't as hot as I thought it should be,as no spark that I could see. After it cooled overnight it fired right up,no problem. I mowed a bit and restarted it several times with no issues,started every time. I think this is a 1995 engine according to the ID tag. I am wondering if there is a upgrade hotter magneto for this engine. I know there is a ton of good knowledge here,so this is the best place to ask. TIA!
There's not a hotter coil other than an OEM briggs coil, a old coil or a coil that's got one foot in the grave and a the other on a banana peel can get weak when it heats up.
Briggs 394891 (superseded TO 590781) is the magnetron coil, meaning for the twins without points.
 

SamB

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Were you using 10w40?
No,Shell Rotella straight 30W
If you read the specs label,Rotella isn't recommended for gasoline(Spark) engines,but this is because the large amount of anti-wear additives ,mainly ZDDP,are not compatible with automobile engine catalytic converters. Modern car engines usually don't have flat tappet lifters and other rubbing surfaces that require large amounts of anti-wear additives that older engines did.
Added oil info
Shell tech advises that "Shell Rotella T4 Triple Protection has 1200 ppm of Zinc " more than the oils recommended for gas engine vehicles,due to their use of catalytic converters. ZDDP causes long term deterioration of the converters. However,the high amount of ZDDP offers a high degree of wear protection for older engine designs such as vintage high performance cars and OPE engines.
 
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SamB

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There's not a hotter coil other than an OEM briggs coil, a old coil or a coil that's got one foot in the grave and a the other on a banana peel can get weak when it heats up.
Briggs 394891 (superseded TO 590781) is the magnetron coil, meaning for the twins without points.
That is good info for me. I see on Amazon,they have the 590781 coil listed for a 42A 707,which is what I have. $15.00. Not a bad price,but a bit of a job getting to on this engine. Briggs didn't skimp on shrouding or number of bolts holding them on on this engine!
 

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SamB

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That is good info for me. I see on Amazon,they have the 590781 coil listed for a 42A 707,which is what I have. $15.00. Not a bad price,but a bit of a job getting to on this engine. Briggs didn't skimp on shrouding or number of bolts holding them on on this engine!
Follow-up on the weak spark/coil issue. I got the new coil from Amazon,put it on and the engine fired right up,sounding better than it ever has.
I went out and found the tallest grass I had around the yard and mowed for a half hour or so. I then restarted the engine several times while it was as hot as it was ever going to be and it started in less than 2 turns of the crank,every single time ,with no hesitation at all. Replacing the coil isn't a big job on these opposed twins,just takes a bit of time,easy time at that.
 

SamB

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Thanks for all the positive comments on the Briggs opposed 2 cylinder engine. I really wasn't wanting to spend major money on another Intek engine that seems to have inherent reliability issues. I know,I know,there are those that will sing their praises. That's ok with me,but I have had 2 that ,for no apparent reason,self-destructed,so I am perhaps a bit gun-shy.
After a few hours of planning,fitting,bolting down and wiring,the Snapper mows again! I'm working on actual muffler mounts,coming off the rear,but(shame,shame) bailing wire is working real good right now! :-D
The I/C 18hp opposed is so much smoother and quieter than the Intek single,it's amazing. Like I said,thanks for the encouragement to do this. After all, I had the engine to begin with,so no real loss but time. Since I'm retired,no issue there either.
Well,the old 18hp twin just wasn't cutting it this Spring,(sorry for the pun:) and I could see one side of the exhaust wasn't getting as hot as the other side Shorting out the 'good' side spark plug almost let the engine die. Doing the same on the 'bad' side had no effect on the rpms. Swapping sides with the plug wires changed nothing. I didn't have time to really get deep into just what the problem was,so off it came and a brand new 500cc single went back on in it's place. I'll get deeper into what the issue may be with it,but for now,it's back on the shelf and declared surplus!
 
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