Model # 121Q02-2025-F1

Internet #205158162

Briggs & Stratton 850 Pro Series OHV Ready Start Gas Engine

Briggs & Stratton

850 Pro Series OHV Ready Start Gas Engine

$21920 /each
store icon Loading Buying Options...
package icon Loading Buying Options...
Sorry, but we ran into issues loading these options. Please try refreshing.

Frequently Bought Together

Product Overview

Briggs & Stratton builds the engines most of America’s best leading power equipment brands depend on. We’re also the engine most preferred by consumers nearly 60 million households trust their yard care to Briggs & Stratton power. America’s most-trusted brands count on Briggs & Stratton power to stand behind their promise of performance. We know what it’s like to have your name on the line. For more than 100 years, we’ve been living up to ours.

  • Vertical engine
  • Dura-bore cast iron cylinder sleeve for extended life
  • Large-tube muffler reduces noise levels
  • Overhead valve design (OHV) for cooler operation
  • Mechanical torque control for additional power
  • Large rewind starter reduces pulling effort for easy starting
  • Commercial-grade air cleaner with dual seals for longer engine life
  • Ready start provides easy no prime, no choke starting
  • Maintenance-free magnetron electronic ignition for quick, dependable starts
  • Crankshaft: 25 mm Dia x 3-5/32 in. L, 2 WK and keyway




Warranty / Certifications

More Products With These Features


Customer Questions & Answers

What horse power is this motor

Asked by: James
Power rating is based on torque, not HP. Rated at 8.5 gross torque. Equivalent would be about 5 HP.
Answered by: CG
Date published: 2017-05-17


Asked by: JAY
No- splash lubrication with no filter.
Answered by: CG
Date published: 2016-09-16

Is this an exact replacement for a Toro Timemaster, the first year they came out?

Is this an exact replacement for a Toro Timemaster, the first year they came out?
Asked by: jelp2
This is not the direct replacement, it may be compatible. Compatibility will depend on crankshaft specs, bolt patterns, type of equipment, etc. Your best resource for information is through one of our local sales centers. They can offer suggestions based on the product the engine is mounted to. You can find local service centers in your area by navigating to our website ( and then clicking the support tab located at the top of the screen, this will drop down a menu which wiil have our dealer locator on it. This will provide you with local dealers in your area that can assist you in replacing that engine.
Answered by: Briggs & Stratton
Date published: 2017-05-11

I want to replace a Tecumseh 148CC 4.5 HP with either the 850 Pro or the EXi 725 and which one wo...

I want to replace a Tecumseh 148CC 4.5 HP with either the 850 Pro or the EXi 725 and which one would provide more power to the blade without bogging down in thick, full 419 Tiff grass? Best performance, longevity, etc.? Price is not an issue in this case.
Asked by: CW
I would go with the Exi 725 because it has more application options, the 850 series is limited to a vertical shaft application, and the 725 series is quite expansive. Your best resource for assistance in finding the motor to best use in this application, I would contact a local Briggs and Stratton dealer, you can find one in your area by navigating to our website at ( and there is a support tab located at the top of the screen, if you hover over this tab it will drop down into a menu, where on the right will be our dealer locator.
Answered by: Briggs & Stratton
Date published: 2017-05-08
  • y_2017, m_7, d_19, h_10CST
  • bvseo_bulk, prod_bvqa, vn_bulk_1.0.0-hotfix-1
  • cp_1, bvpage1
  • co_hasquestionsanswers, tq_5
  • loc_, sid_205158162, prod, sort_[SortEntry(order=NUM_ANSWERS, direction=DESCENDING), SortEntry(order=SUBMISSION_TIME, direction=DESCENDING), SortEntry(order=LAST_APPROVED_ANSWER_SUBMISSION_TIME, direction=DESCENDING), SortEntry(order=LAST_APPROVED_ANSWER_SUBMISSION_TIME, direction=DESCENDING), SortEntry(order=BEST_ANSWER_FEEDBACK_COUNT, direction=DESCENDING), SortEntry(order=POSITIVE_ANSWER_FEEDBACK_COUNT, direction=DESCENDING), SortEntry(order=NUM_ANSWERS, direction=DESCENDING)]
  • clientName_homedepot
  • bvseo_sdk, java_sdk, bvseo-3.1.1
  • CLOUD, getContent, 104ms

Customer Reviews

850 Pro Series OHV Ready Start Gas Engine is rated 4.6 out of 5 by 10.
Rated 5 out of 5 by from Briggs 850 Good experience with order and pick up. Pricing is competitive. Engine has good torque and easy starting.
Date published: 2016-09-16
Rated 5 out of 5 by from Easy Purchase and Install Easy Purchase and Installation. I would recommend shopping from home anyday.
Date published: 2016-08-14
Rated 5 out of 5 by from 850 pro engine Excellent starts first pull plenty of power and torque.
Date published: 2016-08-16
Rated 1 out of 5 by from No durability I bought this engine from an authorized Briggs dealer in 2010. First engine came with a cracked block and I had to fight tooth and nail to get it replaced. After two months of battle I finally got a replacement, more due to the excellent folks where I bought it and not on Briggs end. For two years this "Pro" grade engine worked great, started on first pull, plenty of guts and fairly quiet. One month after the warranty ended it's all done. It just stopped running while I was mowing. It did not seize, had plenty of gas, oil was clean and a good filter. Brought it to my repair shop and they said the cam came off the shaft and sheared the oil pump off inside the engine. Briggs response, "Warranty is over". My repair guy plead the case that the rest of the engine was spotless inside and he could not find a reason for the issue, especially not on my end. Briggs response, "Calendar date" meaning once again that I was out of warranty and they would offer no help. So now after 25 years I am no longer a Briggs customer, I will be looking to Honda which is a shame because I believe in buying Amercian Made, but not Briggs....P.S. This was used once a week as a homeowner.
Date published: 2012-09-16
Rated 5 out of 5 by from Best Engine you can put on a push mower and here is why. I don't own this engine but I have a family member who does and I have got to use it a few times. I'm going to compare this engine with a Honda GXV160 and tell you why I would pick this engine if I were to buy another commercial push mower. Alright in terms of power, the GXV160, I'd say that is the single most thing I dislike about it, it doesn't have enough. This engine does have the power and I fear it may have too much in the situation where you hit a big root or something. But still the I give the Power point to the Briggs. Terms of reliability, ok lets see here. In terms of starting, both this engine and the honda are an exceeds...I prefer the one or two pulls on the briggs though, to the manual choking on the Honda. But I'd still say its a draw. Now for the big one, Reliability. Both these engines seem to be reliable, both have something I say could be improved. The Briggs starts easy and runs great, so does the Honda. What could be improved on the Briggs, well a stronger crank, maybe a double ball bearing setup like the honda, because it is more powerful so therefore it would be more likely to break if you hit sidewalk or a root. Easy solution, don't use fancy mowers by sidewalks or rooty trees, I still wouldn't do it with a Honda GXV, just use a cheap mower or a weed eater. Ok now what can the "Legendary" honda improve on? Well, the choke system I mentioned earlier. If you get a branch from a small bush or something in the choke system and it bends, then you are going to have fun fixing it or paying 50 bucks an hour to get it fixed. Honda's GXV engine is no good if you can't set it on the right rpm or choke it, and its sad it relies on a small piece of metal attached to a spring that has a guard that doesn't completely cover the mechanism. Sounds like an achilles heal to me. This actually happened to me lol, my "bullet proof" honda commercial mower. In terms of reliability, I will have to give it too the honda, even though it was close...I'd rather fix a bent piece of metal than a bent crank or worse. Performance, well lets see. Briggs, doesn't bog down even in thick wet grass while mulching. Honda, bogs down in wet grass if you haven't mowed for 10 days. Now in reverse, Honda uses less fuel...and is quieter than the briggs which is still a pretty quiet sounding engine. Verdict- I give it to briggs, I'd rather burn a little more gas and not be restarting my mower every 2 minutes when it bogs. Value- the briggs 850 you can get a new engine for under 850 on amazon, the honda is around 400. Terms of whats more for the buck, I say the briggs only because it is cheaper. But too be fair, if you want a fuel efficient very nice sounding engine, the honda is for you. If you want an engine thats gonna get it done in faster in bad conditions you want the briggs 850. Now in conclusion briggs has more points than the honda on my scale. I think it is more of an ideal choice for most conditions. Easier to get parts for, easier to work on than the honda. But by no way am I saying honda is junk it definitely isn't. But if Honda made a 190 gxv it would be a more fair comparison.
Date published: 2012-05-18
Rated 5 out of 5 by from A Real Bang for the Buck The 850 (5 hp) B&S is a smoking hot engine that gets the job done! When cutting grass, is seems like an easy task and not a chore when the 850 is running. It helps me with my walking exercise when I want to go at a faster pace while still getting the grass cut in a nice uniform manner. Everyone should try the 850 before buying another manufacturer's product.
Date published: 2012-08-09
Rated 5 out of 5 by from Great Powerplant I purchased this engine to refurbish a John Deere JS63 walk behind I found through an on-line search. It starts first pull everytime and cuts through thick grass easily. I like the Easy Start feature eliminating the need for a primer bulb and the fact that my wife can easily pull the starter cord without feeling intimidated.
Date published: 2012-04-27
Rated 5 out of 5 by from No Durability To the guy that Briggs wouldn't warranty his engine because the warranty expired. I work for a Power Equipment manufacture. Not Briggs And Stratton. I understand your disappointment at not being offered Good Will assistance but Briggs fulfilled their obligation to the full term of the warranty. Manufactures cannot help with warranty on every request on units beyond the warranty period. It's not like there's huge margins on equipment and a company can give away a replacement for each unit sold. Each situation is different and needs to be judged independently. There obviously was no compelling reason in your particular case. By the way I have this engine and it's awesome.
Date published: 2015-05-23
  • y_2017, m_7, d_18, h_22
  • bvseo_bulk, prod_bvrr, vn_bulk_1.0.0-hotfix-1
  • cp_1, bvpage1
  • co_hasreviews, tv_0, tr_10
  • loc_, sid_205158162, prod, sort_[SortEntry(order=RELEVANCE, direction=DESCENDING)]
  • clientName_homedepot
  • bvseo_sdk, java_sdk, bvseo-3.1.1
  • CLOUD, getContent, 119ms