79cc Predator engine mods help

Looking to get as much HP out of the predator engine it’s a 3hp I would like atleast 5hp what mods would have to be done and where can they be purchased ?
Thank you


Well-Known Member
I had a feeling you were asking for a specific reason. The problem is that there aren't any speed parts available for the 79 or 99cc.


Well-Known Member
I learned something.

Still though, I wonder how long the stock rod and flywheel last with a modded engine that has every upgrade but those two things.
If you absolutely have to go with a 79cc your best bet is to look for a well respected automotive shop that specializes in rebuilds. While not a car, an experienced machinist will have no problem taking precise measurements, know how to get maximum power, where to locate parts, fabricate parts himself, or offer the exact advice your looking for. If he doesn't have the time to work on a small engine he probably would know the next best place to go. Expect to spend much more than you thought.
There is "NO" internal mods for that engine. Nobody makes the billet rod, crank, flywheel, etc. Best you could do is header, air cleaner, carb. Maybe shave the head.
The only performance parts for the 79cc are a camshaft and valve springs. Through AGK which is a rewelded stock camshaft that will give you a cam with 0,48 added lift and a little more duration.I have a modified 79cc in my mini bike that I've been working on for well over one year now. Working on for getting it to run faster and so far I am very happy with the results. My engine has the following done and I did all the work less the milling of the head and cam myself. I took the engine all the way down.Inspected it then polished out every single mated moving part.Removed the gov and plugged the case hole.A full port and polish and reworked the bottom side of the oil dipper so its knife shaped.I doubt that does much but anything and everything you can do to this engine. Really helps it responds very well to anything in its favor.Then had the head milled from 8.5-1 up to 10.4-1 which is the most you can go and run pump fuel. Then I added the cam and 18 or 22 lb valve springs so it wont have any valve float issues. And both a copper head and exhaust gaskets. Which happen to be the only way to go.Since I remove my exhaust often do to the many mods I come up with and try. And the exhaust header pipe never ever leaks.Then I painted the engine with a high heat cast iron paint and cleaned up the cooling fin lead edges and polished those out to look like chrome. Then reassembled the engine and used all stainless allens to hold the engine cases together and all else on the outside of the engine.The entire mini bike is done this way. I built a custom fully tunable exhaust that works excellent and sounds real good.By using the typical header pipe sold for this engine in a one inch x 11 long. And bought a 3 inch supertrapp disc muffler through summitracing.com. I had to go to a local auto parts store to get the pipe closest to both sizes.Being the header pipe and the inlet to the muffler. The three inch happens to come in different inlet sizes.Pick the one closest to the header being a 1-3/4. I had to slit the intermediate pipe and remove the exact amount needed then in a vise I rewelded it and then onto the other two parts.To end with a nice looking custom exhaust that is fully tuneable. For the intake side there is only one carb to use as far as I am concerned thats a 18mm mikuni VM carb.That I picked up the only aluminum manifold that was close enough to make it work.A manifold made for it but to use on a china two stroke.So both the port end by the head port side and those mount holes are wrong. You have to use a rotary power tool like dremel and open them up.As for the port on that end I made a form and filled around the form with JB weld.Plus I run a open velocity stack on the carb. I also cut off all unwanted casting posts from the engine. So its clean and looks great. As for how well the engine will hold up to all this and when the new cam will spin the engine to a whopping 7 grand! It holds up just fine! Ive ran this one there every time I ride it since Im test tuning.Which in fact is now finnished. To say Ive no doubt to have one of the fastest 79cc minis around. This little dude flat gets it on!
I bought mine from both AGK and ebay.If you buy the carb on ebay make sure its a genuine mikuni and not a china knock off like I got the first time they suck! Shane at AGK knows this engine well and so do I so ether of us can help you with any questions you may have
To answer your question on what to expect with the same mods as done to my engine.The hp will come up to 7 hp! However part of it is built off the rpms the rest is right off idle.My engine comes on strong in the mid range area about like a poor mans turbo no kidding.Its amazing however it took alot of work and test rides to get it here.Which I can help you get the same right away, since I already did all the test work. I don't know what sized wheels or tires your to run.Mine are 13 inch and do to that and the size of this engine.A billet flywheel wouldnt do you any good.Since both the 13 inch tires and small bore will not bring the benefits of a billet alive until the upper mid range. That's if you could get a company to make you one.I have looked everywhere on and off the internet to tell you its not out there.AGK gets them and will only offer one with his built engines.However he agreed with me for whats seen from using one on this engine. Your better off with the stock do to its added weight.As for it coming apart and the real reason for using the billet.Mine has held up fine and so do others.Some of the go-kart race guys have spin theres up to 10 grand. The engines that see real good from a billet are all the bigger displacement.And with go-kart height wheels and tires .Which do not work well on a mini bike unless you run a jackshaft setup and those add more weight and friction all killers of performance.Think like this reduce all friction as much as at all possible and all larger radius parts that turn on the drive train. When possible as well keep it all light. I use a max torque clutch that I reworked and is now much lighter and with less friction through out except for the obvious shoe face and contact area period. And I run the go-kart adapter plate made from T6 with the light go-kart racing sprockets and extreme chain.That chain is 10% lighter plus I moved the engine back to remove a few chain links. I also removed that thick steel engine mount plate and made a new smaller exact fit unit out of T6 that is now rubber mounted. And use the best quality wheel bearings you can afford.IF serious about performance. So I run a street tread thats smooth like a sport bike runs.