small engine experts - help
 

well my trusty 11 year old sears 5hp snowblower is showing its age. i know at the very least i need to get a carb tune up kit for next year. i was wondering if i could put a bigger motor on it, like a 7 or even a 9hp tecumseh. i know very little of what issues i might run into. i know that i have to match the base and shaft sizes at the very least. it would save me half the price of a brand new one if this could work. anyone?

yeh, if you can match those things you should ne good to go...

You might have problems getting the same shaft diameter. Generally the 5HP engines have a smaller shaft than a 7HP engine. The other problem you might have is that the larger HP engine might not fit in the same area allocated for the smaller engine.

If you want to save $, i suggest you rebuild the carborator on your 5HP engine.

I have a 25 year old ariens snowblower that runs like new. I purchased it used 5 years ago, the previous owner had rebuilt the carborator then. This year I had to replace auger bearing. I always run the gas out of it and change the oil at the end of the season so that it is ready for the beginning of the next season.

Yes, I also think that it would be best to try and rebuild/cleanout your existing carb... Make sure you have fresh oil and a new spark plug also..

I have rebuilt a few small engines before and a carb cleanout can really do a world of difference. :D

yeah, i change the oil, drain the tank and replace the spark plug every year. even do the recommended re-lubing. i want to be able to blow through wet drifts like my neighbor does with his new 9 hp. i've browsed the tecumseh catalog and the 5 and 7hp engines seem to have similar shafts and base. i'll give the dealers a call. i believe there's no substitute for displacement!

If you want more power put a turbocharger on it :D

i guess it's just three storms in a row that got to me. this year i went all out and used synthetic 5-30! no problems starting in cold weather at all (not that i ever did)...

What is a 'snowblower'? :D

Not to be a smart aleck but most carbs, (especially on smaller engines like this) hate boost, and will not operate correctly under boost.

Not to be a know-it-all but I have modified an old 2HP B&S engine from an old snowblower for use on a minibike which now is capable of taking my 175lb body over 45 MPH.

The modifications I did to it were sand the head down (less than the thickness of the head gasket) to raise the compression, install a stiffer spring in the governer to keep the revs higher, install a hotter spark plug, and use thicker oil (Mobil 1 15W50) to help keep the oil from going past the rings due to the higher compression.

Before the mods the minibike was not capable of moving me up a small incline, now it has great pick-up speed (expecially with a centrifical clutch) and I have been clocked at 48 MPH from a moped.

hmmm, shave the head, maybe port and polish the exhaust? :rolleyes:

If the carburators don't like boost, put fuel injection on it :P

Nitros Oxide for those runs down the sidewalk...... :D

Don't know of any turbo small enough to work.....

If you wanted to change engines keep in mind the crankshaft output size and dimensions.....they are not all the same size.....

It's a snow blower
 

Nitrous for those really deep drifts :rolleyes: