HF 79cc question for new build

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MarkSumpter

New Member
Nov 27, 2010
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Ohio
Like what was posted before here is all you really need I would think... I am going to give on a shot when I find out for sure it will fit the new 99cc Predator that HF has. I got 4 of the 79cc's on close out a few weeks back for $35 each and but am dying to get a Predator...

affordablegokarts: 79cc Parts
 

MarkSumpter

New Member
Nov 27, 2010
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Ohio
My local HF has been out of stock on those for MONTHS. :(
Yea mine had a Pallet load left and I know the manager there well so when he had the last tent sale he told me to come on sunday and he would make me a deal and he darn sure did... I only wish I had more money to get all he had left. All gone now though. I forgot that I got 2 of the 6.5's for $30 each that were returned. One had the ex rocker arm loose and not opening the valve and the others oil sensor was bad.
 
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daRog

New Member
Apr 15, 2011
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California
And he won't have any soon. The 79cc engine has been phased out, and the 99cc Preditor engine is their replacement.
I realize that. My local HF sold out of them and they were discontinued before they could get any more. As for the Predator 99cc, it's still on backorder locally and on HF's website.
 

LS614

Active Member
Dec 22, 2009
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CT and MA
I would like someone to find a stamped serial number on the predator so I can prove a point. I'm pretty sure they are the same factory and model number as the greyhound with the claim of a larger displacement lol
 

WayneC

New Member
Aug 2, 2009
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Clearwater, FL
Same for mine. My maxtorque engagement rpm was 2200 if I remember right. I ordered an 1800 rmp spring and have a little trouble with it trying to engage at idle.

I just heard back in an email from James Donovan at MaxTorque regarding engagement RPM of the stock belt pulley clutch...
..."Stock clutch will come in around 2,200rpm."
I'm set to go then!
 

sanelson

New Member
Mar 5, 2011
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denver
Just got my qmatic and was in the process of installing it when low and behold the PTO shaft on the engine is 11/16 instead of 5/8. Now I have to get the 2 1/2 inch pulley reamed out 1/16 of an inch and possibly the keyway. Anyone have this same problem?
 

LS614

Active Member
Dec 22, 2009
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Quenton made my Qmatic custom for me, so it was made for the HF. Sorry you didn't have the same luck
 

sanelson

New Member
Mar 5, 2011
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denver
This qmatic was built also for the 79cc. Quenton drilled the mounting holes to fit the HF - that was very nice of him. I don't know if the 79cc's have a larger pto then 5/8's. I called all the Harbor Freight stores here in Denver to see if there were any left so I could go measure them but no luck. Supposedly the 99cc's have 5/8 shafts. A machinst friend of mine is going to alter the pulley to fit the shaft tomorrow for me. The engine fits in my frame with room to spare - no need to take the gas tank or exhaust off. I still have about 4 inches from the top of the gas tank to the cross bar on the bike. I also tightened the external spring on the govenor arm, stuck a tach on the engine and it rev's 5000+ rpm's. Can't wait to get this on the road.
 

wayne z

Active Member
Dec 5, 2010
1,743
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louisiana
Yes, my new HF 99cc black Predator engine has a 5/8" pto shaft. A real tight 5/8 it is too! Had to lightly drive the die cast pulley onto mine with a 13/16 deepwell socket.
 

NewOrleansFlyer

New Member
Jun 27, 2011
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Montana
I've checked HF online and they don't even have the 79cc motor listed. I prefer the standard look of the china girls, but would like to pick up one of these for a belt drive build. Any suggestions? Thanks
 

MarkSumpter

New Member
Nov 27, 2010
474
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Ohio
I've checked HF online and they don't even have the 79cc motor listed. I prefer the standard look of the china girls, but would like to pick up one of these for a belt drive build. Any suggestions? Thanks
The 79cc Greyhound engine was discontinued about a month ago... They have the new Predetor 99 cc that replaced it. Some stores still have the 79cc though I have 7 of them I got for $35 each from my local store.
 

wayne z

Active Member
Dec 5, 2010
1,743
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38
louisiana
I've checked HF online and they don't even have the 79cc motor listed. I prefer the standard look of the china girls, but would like to pick up one of these for a belt drive build. Any suggestions? Thanks
Check out how I reversed the engine on my Predator in frame build for that "standard " in frame look.

Look at the later posts in the DIY forum thread called"Predator in frame fricton drive" The last pic I posted there is a good one. Might give you some food for thought.

If you like the 79cc, you'll love the 99cc. Awesome little engine. I'm gettin 38-40 mph.max . Cruise 30-32 easily

After you drive one of these smooth quiet powerful engines, you won't want to drive a chinagirl much anymoreLOL
 
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wayne z

Active Member
Dec 5, 2010
1,743
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louisiana
Oops, I forgot about those pis of a new build I posted this morning. You'll have to go back a few posts to see the Predator pics.

Check out how I reversed the engine on my Predator in frame build for that "standad " in frame look.

Look at the later posts in the DIY forum thread called"Predator in frame fricton drive" The last pic I posted there is a good one. Might give you some food for thought.

If you like the 79cc, you'll love the 99cc. Awesome little engine. I'm gettin 38-40 mph.max . Cruise 30-32 easily

After you drive one of these smooth quiet powerful engines, you won't want to drive a chinagirl much anymoreLOL
 
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sanelson

New Member
Mar 5, 2011
25
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0
denver
Hi Folks, Just go my 79cc build completed (with a qmatic) and had it out for a test drive. Everything on it is stock including the govenor, although I shortened the govenor spring and had the tach to the mid 4000's. The bike runs very well on the flats cruising in the mid-high 20's but the hills I encounted, that were of any steepness, the engine was gutless and didn't get any faster than 10mph with lots of pedeling. The gear ratio is 11.55 X 1 (56 tooth rear sprocket). This is useless to me as I ride where there are lots of hills. Per Quenton 60t = 12.38, 62 = 12.79, 66t = 13.62. Anyone use a sprocket other than a 56t? Other mods besides rejetting the carb to get hill climbing respectable? My rear chain drive using an HS 49cc at 20.8 X 1 was giving 21-22 on the flats and 17-18mph on the same hills. This bike is waiting for a rear wheel rebuild so I was hoping the 79cc would be the answer. ugh...

Steve