Re-powering a 3 HP 1987 MTD edger with Lifan 4 HP engine ( LF160F-AQ)

wdn

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Aug 6, 2018
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Over the weekend I re-powered a 1987 MTD model 604 edger replacing the original 3 horsepower engine with a brand new Lifan LF160F-AQ engine. The new engine is 4 HP and 118cc displacement, and comes with a 3-year warranty. The original engine was a tired 3 HP Briggs and Stratton with a broken recoil starter. The inside of the gas tank was not looking too good either.

Here is the before picture. I had cut a hole in it and used a 24 mm impact socket on the crankshaft to start it with an electric drill the last few times. This was not a long term solution.

IMG_5008.jpg


Here it is after I removed the Briggs and Stratton model 80202-1830 engine and cleaned off the deck. I also replaced all four wheels and put on a new blade and drive belt before changing engines. I also changed the two 5/8" ball bearing on the blade assembly. It spins like a brand new edger.
IMG_5014.jpg



Using a 10" length of 1x6 pine as a riser, I drilled mounting holes in the original spots since the new engine need about 3/4" of height. For mounting I used 4 stainless steel hex bolts 5/16x18 and 2-1/2" long, with stainless steel nuts and lock washers. The original bolts were 1-1/2" long. The board is just the right length to still see the MTD nameplate.:
IMG_5021.jpg

Next I mounted the brand new 4 HP Lifan LF160F-AQ engine. The mounting holes lines up perfectly. It was a perfect fit though a tight fit. I would say this is the biggest engine that would physically fit the edger.
IMG_5026.jpg

IMG_5027.jpg

Note that the Lifan engine fits perfectly and does not interfere with the wheel height adjustment bracket of the MTD edger, not at all. I saw on YouTube a guy had used a 79cc 3 HP Predator engine from Harbor Freight and could not get it to fit without completely cutting off the height adjustment bracket rendering it inoperable.
IMG_5028.jpg
IMG_5029.jpg

I bought a new 2-1/2" pulley to replace the MTD 2-3/8" pulley that is now unobtainable. Using an abrasive sanding drum on a Dremel tool I took down some metal on the height adjustment bar so it does not hit the crankshaft keyway. I took off maybe 3/16". The pulley has two Alen screws one pressing down on the key and the other 90 degrees away tightens on to the crankshaft. I used blue Loctite on both. The engine takes a 3/16x24 crankshaft bolt I have not bought one yet.

IMG_5032.jpg

The trickiest part was hooking up the remote throttle cable so the engine is WFO throttle when the lever is pressed all the the way. It took some fiddling at both ends of the cable and adjusting a tension screw on the throttle so the lever on the handlebars is easy to move yet holds its position. I also added an induction type hour meter. I filled it with 17 ounces of Mobil 1 Advanced 10W-30 and some 94 octane gas. The tank takes 2/3 gallon and is quite a bit bigger than the one on the old engine which I think was one quart.

The new engine started on the first pull I let it idle at various speeds for 15 minutes no load then put the MTD to work again both as an edger and as a trim mower. When done I let it idle at no load a few minutes to cool down then shut it off. The new engine now has 1.0 hours on it.
IMG_5058.jpg

The 4 HP Lifan engine is a lot more powerful than the 3 HP Briggs, more than the extra 1 HP would suggest. Before buying this engine I did some reading that it is considered quite powerful for a "4 horsepower" engine. Moving the throttle lever to idle it is so quiet you can hardly hear it. Wide open it is still quite a bit quieter to the Briggs and has a smoother sound to it. It made mincemeat of areas that the old engine could not cut and that would actually stall the Briggs engine. It did not bog down in the RPM one bit. It was astonishing the difference in power. The slightly larger pulley turns about 5% faster than the original MTD pulley.
 

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Wow, that came out p!ssah. Nice job man!

I love repower projects. Where did you acquire the Lifan? Small engine prices have gone up quite a bit. I have a spare Predator 79cc that I bought (with a bunch of other stuff) with a family discount coupon code and it came to $65. Now they're $129!
 

wdn

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Thanks. I bought the Lifan engine from Home Depot, ordered it online and had it delivered to the store where I picked it up. That way I could look at the shipping carton before accepting it. I started another thread here a few weeks ago about how Predator engines are now overpriced for what you get. The Lifan are more than a cut above in quality, yet HF raised their prices so the Predator costs nearly as much as a Lifan from HD yet only has the 90-day warranty. Lifan offers 3-years warranty and they stock all the parts for them.
 
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I just read that thread, thanks. Also remembered you in the Ironton thread. I'm always repairing something for myself or a friend, so for the price, I ended up getting one of the 208cc engines as well.
 
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Messages
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I repowered my early '90s model about 3 years ago. It had a B&S 3.5hp engine that looks the same as yours did, with the exception of the air filter.

It had a rusty gummed up fuel tank and was hard to start. I rebuilt the carb with new diaphragms etc, but still never ran great.

The shaft on the new engine was longer than the stock one. I had to get some spacers from Ace Hardware and welded on a strip of steel to extend the pulley cover out. I was going to leave the cover off at first, but then realized the cover keeps the belt from coming off the pulley when the blade is disengaged. I removed the throttle cable and stuck with the engine mounted throttle to keep it simple.

The new engine is a B&S 127cc. It looks like all the other Chonda clones out there. At the time it was the cheapest CARB approved engine I could find at $199.

It runs and works just like new now.

On all of my power equipment that has a fuel shut off, I shut off the fuel valve and let the carb run dry when I'm done. Haven't had a problem with gummed up carbs since.
 

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Over the weekend I re-powered a 1987 MTD model 604 edger replacing the original 3 horsepower engine with a brand new Lifan LF160F-AQ engine. The new engine is 4 HP and 118cc displacement, and comes with a 3-year warranty. The original engine was a tired 3 HP Briggs and Stratton with a broken recoil starter. The inside of the gas tank was not looking too good either.

Here is the before picture. I had cut a hole in it and used a 24 mm impact socket on the crankshaft to start it with an electric drill the last few times. This was not a long term solution.

View attachment 58742

Here it is after I removed the Briggs and Stratton model 80202-1830 engine and cleaned off the deck. I also replaced all four wheels and put on a new blade and drive belt before changing engines. I also changed the two 5/8" ball bearing on the blade assembly. It spins like a brand new edger.
View attachment 58746


Using a 10" length of 1x6 pine as a riser, I drilled mounting holes in the original spots since the new engine need about 3/4" of height. For mounting I used 4 stainless steel hex bolts 5/16x18 and 2-1/2" long, with stainless steel nuts and lock washers. The original bolts were 1-1/2" long. The board is just the right length to still see the MTD nameplate.:
View attachment 58747
Next I mounted the brand new 4 HP Lifan LF160F-AQ engine. The mounting holes lines up perfectly. It was a perfect fit though a tight fit. I would say this is the biggest engine that would physically fit the edger.
View attachment 58752
View attachment 58753
Note that the Lifan engine fits perfectly and does not interfere with the wheel height adjustment bracket of the MTD edger, not at all. I saw on YouTube a guy had used a 79cc 3 HP Predator engine from Harbor Freight and could not get it to fit without completely cutting off the height adjustment bracket rendering it inoperable.
View attachment 58754 View attachment 58755
I bought a new 2-1/2" pulley to replace the MTD 2-3/8" pulley that is now unobtainable. Using an abrasive sanding drum on a Dremel tool I took down some metal on the height adjustment bar so it does not hit the crankshaft keyway. I took off maybe 3/16". The pulley has two Alen screws one pressing down on the key and the other 90 degrees away tightens on to the crankshaft. I used blue Loctite on both. The engine takes a 3/16x24 crankshaft bolt I have not bought one yet.

View attachment 58756
The trickiest part was hooking up the remote throttle cable so the engine is WFO throttle when the lever is pressed all the the way. It took some fiddling at both ends of the cable and adjusting a tension screw on the throttle so the lever on the handlebars is easy to move yet holds its position. I also added an induction type hour meter. I filled it with 17 ounces of Mobil 1 Advanced 10W-30 and some 94 octane gas. The tank takes 2/3 gallon and is quite a bit bigger than the one on the old engine which I think was one quart.

The new engine started on the first pull I let it idle at various speeds for 15 minutes no load then put the MTD to work again both as an edger and as a trim mower. When done I let it idle at no load a few minutes to cool down then shut it off. The new engine now has 1.0 hours on it.
View attachment 58758
The 4 HP Lifan engine is a lot more powerful than the 3 HP Briggs, more than the extra 1 HP would suggest. Before buying this engine I did some reading that it is considered quite powerful for a "4 horsepower" engine. Moving the throttle lever to idle it is so quiet you can hardly hear it. Wide open it is still quite a bit quieter to the Briggs and has a smoother sound to it. It made mincemeat of areas that the old engine could not cut and that would actually stall the Briggs engine. It did not bog down in the RPM one bit. It was astonishing the difference in power. The slightly larger pulley turns about 5% faster than the original MTD pulley.
Nice job! I've never seen or used one of these before.

I just trim and edge with a string trimmer.
 
Joined
Apr 18, 2021
Messages
589
Location
Conway, sc
Over the weekend I re-powered a 1987 MTD model 604 edger replacing the original 3 horsepower engine with a brand new Lifan LF160F-AQ engine. The new engine is 4 HP and 118cc displacement, and comes with a 3-year warranty. The original engine was a tired 3 HP Briggs and Stratton with a broken recoil starter. The inside of the gas tank was not looking too good either.

Here is the before picture. I had cut a hole in it and used a 24 mm impact socket on the crankshaft to start it with an electric drill the last few times. This was not a long term solution.

View attachment 58742

Here it is after I removed the Briggs and Stratton model 80202-1830 engine and cleaned off the deck. I also replaced all four wheels and put on a new blade and drive belt before changing engines. I also changed the two 5/8" ball bearing on the blade assembly. It spins like a brand new edger.
View attachment 58746


Using a 10" length of 1x6 pine as a riser, I drilled mounting holes in the original spots since the new engine need about 3/4" of height. For mounting I used 4 stainless steel hex bolts 5/16x18 and 2-1/2" long, with stainless steel nuts and lock washers. The original bolts were 1-1/2" long. The board is just the right length to still see the MTD nameplate.:
View attachment 58747
Next I mounted the brand new 4 HP Lifan LF160F-AQ engine. The mounting holes lines up perfectly. It was a perfect fit though a tight fit. I would say this is the biggest engine that would physically fit the edger.
View attachment 58752
View attachment 58753
Note that the Lifan engine fits perfectly and does not interfere with the wheel height adjustment bracket of the MTD edger, not at all. I saw on YouTube a guy had used a 79cc 3 HP Predator engine from Harbor Freight and could not get it to fit without completely cutting off the height adjustment bracket rendering it inoperable.
View attachment 58754 View attachment 58755
I bought a new 2-1/2" pulley to replace the MTD 2-3/8" pulley that is now unobtainable. Using an abrasive sanding drum on a Dremel tool I took down some metal on the height adjustment bar so it does not hit the crankshaft keyway. I took off maybe 3/16". The pulley has two Alen screws one pressing down on the key and the other 90 degrees away tightens on to the crankshaft. I used blue Loctite on both. The engine takes a 3/16x24 crankshaft bolt I have not bought one yet.

View attachment 58756
The trickiest part was hooking up the remote throttle cable so the engine is WFO throttle when the lever is pressed all the the way. It took some fiddling at both ends of the cable and adjusting a tension screw on the throttle so the lever on the handlebars is easy to move yet holds its position. I also added an induction type hour meter. I filled it with 17 ounces of Mobil 1 Advanced 10W-30 and some 94 octane gas. The tank takes 2/3 gallon and is quite a bit bigger than the one on the old engine which I think was one quart.

The new engine started on the first pull I let it idle at various speeds for 15 minutes no load then put the MTD to work again both as an edger and as a trim mower. When done I let it idle at no load a few minutes to cool down then shut it off. The new engine now has 1.0 hours on it.
View attachment 58758
The 4 HP Lifan engine is a lot more powerful than the 3 HP Briggs, more than the extra 1 HP would suggest. Before buying this engine I did some reading that it is considered quite powerful for a "4 horsepower" engine. Moving the throttle lever to idle it is so quiet you can hardly hear it. Wide open it is still quite a bit quieter to the Briggs and has a smoother sound to it. It made mincemeat of areas that the old engine could not cut and that would actually stall the Briggs engine. It did not bog down in the RPM one bit. It was astonishing the difference in power. The slightly larger pulley turns about 5% faster than the original MTD pulley.
Very nice build. 😁
 
Joined
Aug 11, 2011
Messages
4,801
Location
N.C.
Nice work! I did the same with a HF engine on an old Sears edger with a Tecumseh engine years ago. I too had some difficulty with the crankshaft pulley/belt combination but finally figured it out. It started and ran like a top compared to the old Tecumseh. I bought a nice used McClane edger for $90 off Craigslist a few years ago and never looked back. The frame/chassis, controls, wheels etc are so much more robust on the McClane than my old Sears. (y)
 
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