# I422 Engine Upgrade



## BigNutzMD (Oct 24, 2015)

So I just purchased this blower over the summer. It runs marginally ok, and I see no reason it wouldn't run like a champ after I put some time into the carb. That said, 4 HP seems a little anemic for a 2 stage blower. They seem to be pretty popular so I'm going to reserve any judgement until after I have an opportunity to try it.

If the performance does underwhelm me, I will start thinking of throwing a larger motor on it in the 7-9 HP range. Does anyone have any experience with this? I'd be concerned about the gearbox being able to handle the additional torque, but it wouldn't surprise me if the same gearbox is used in a few larger models.

Any advice, cautionary tales, or blind encouragement would be greatly appreciate!

BN-MD


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## Normex (Feb 21, 2014)

Welcome to the forum, changing for a slightly bigger engine would not harm anything as long as you're mindful not to take double of what it was designed for.
Look under the Repower section here and many including myself are doing the same of what you propose. If you live near the Canadian border look up Princess Auto where they offer winterized ready engines. Some other members here had had success with Predator engines.


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## detdrbuzzard (Jan 20, 2012)

hello BN, welcome to *SBF!!* depending on where you live and how much snow you receive 4hp might be enough


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## Kiss4aFrog (Nov 3, 2013)

A good running 4hp should do good on a 22" machine. That said if you were to re-power I doubt you'd need anything bigger than the Harbor Freight Predator 6.5 hp.
You can go bigger but you'll never use the power and you'll only be burning more gas.


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## Shryp (Jan 1, 2011)

Certainly nothing wrong with upgrading to a 212cc Predator. It will probably run better and use less gas than the current 4 HP Tecumseh. That being said, older machines were built a lot heavier. The older engines had more torque and more steel/cast iron on them as well as the older gearboxes, augers and impellers. The extra weight of all the moving parts made things more likely to keep moving when hitting a load.


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## BigNutzMD (Oct 24, 2015)

Awesome, thanks everyone. I'm down in Maryland, so while we do get the 10 year blizzards that can drop a few feet, usually I'm looking at 8" or less of snow. 4HP may actually be spot on. 

I am however a budding amateur small engine/ power tool mechanic, so I may not be able to help myself! 

I'll let you guys know!

BN-MD


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## detdrbuzzard (Jan 20, 2012)

i would run the 4hp motor and pick up a predator 212cc when they go on sale. I mostly use one of my toro 521's but would love to put an electric start 7hp motor on one of them


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## GustoGuy (Nov 19, 2012)

Shryp said:


> Certainly nothing wrong with upgrading to a 212cc Predator. It will probably run better and use less gas than the current 4 HP Tecumseh. That being said, older machines were built a lot heavier. The older engines had more torque and more steel/cast iron on them as well as the older gearboxes, augers and impellers. The extra weight of all the moving parts made things more likely to keep moving when hitting a load.


Actually the Predator 212cc engine is at least equal in power to the 8hp Briggs that I replaced. On my minibike it has so much torque that I had to add 3 steel plates two over the front wheel and 1 down low on the frame just to keep the front tire on the ground since it was a bit hazardous for inexperienced riders. I told them to lean forward while accelerating :facepalm_zpsdj194qh but they never seem to listen to me.


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## bwdbrn1 (Nov 24, 2010)

Welcome to SBG BN-MD. I'd agree with detdrbuzzard on that one. Try the 4HP out first to see how it does. You can always get another engine and re-power it if you think it needs it.


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## chiefth (Feb 4, 2016)

I am researching replacing the Tecumseh engine on my I422 with a HF Predator but since the Predator engine has only a single PTO it appears I would have to put a second pulley on the new engine shaft to power the drive system. That requires a second 3/4 bore 1.75 pulley as well as a different size belt. Has anyone done this any help would be appreciated. UPDATE I just found that the 2 PTO shafts rotate in opposite directions so my plan as described above will not work so I'll be looking for a new snow blower. I can't complain since this one has served me well since 1988 and is not reliable.


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## nwcove (Mar 2, 2015)

your current engine has dual shafts ?


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## skutflut (Oct 16, 2015)

chiefth said:


> I am researching replacing the Tecumseh engine on my I422 with a HF Predator but since the Predator engine has only a single PTO it appears I would have to put a second pulley on the new engine shaft to power the drive system. That requires a second 3/4 bore 1.75 pulley as well as a different size belt. Has anyone done this any help would be appreciated.



That throws a bit of a wrench into the works. The second shaft (extended camshaft), which drives you wheels, rotates the opposite direction of the
crankshaft pulley. You will have to investigate if its possible to move your friction wheel to the opposite side of the friction disk and get the speed control adjusted so that you have the forward speeds work. As it is now, you would end up with two forwards speeds, slow, and too slow to be useful, and several reverse speeds, only one or two of which would be any use to you.

People have made the changes, but it adds at least another hour or fifty to the project.


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## db9938 (Nov 17, 2013)

With any of these, I would start with making sure that the carb is clean and adjusted correctly. After that, I would make sure that the valves are adjusted correctly. After, that, check RPM with a tach. 

If everything is within spec, and you are still not happy, then predator may be your answer.


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## dhazelton (Dec 8, 2014)

Try this chiefth


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