Seeutek PK80 80cc Bicycle Engine Kit 2-Stroke Gas Motorized Bike Motor Kit Upgrade with Speedoemter

I've built two motored bikes and am on my third. Here's the deal: You MUST enjoy problem solving and working on engines to get anything out of this kit. I never write reviews, but after seeing so many people complaining because they didn't bother to do any research before they bought the kit, I felt that I should. Yes, they do come with some cheap parts. No, they do not fit every bike. There is no plug and play bike motor kit. If you do not have sufficient mechanical ability, this is not for you. If you can fix a lawn mower this kit is for you. You will have to replace some parts, but they are inexpensive. Your first week riding it there are bound to be some issues. The guide that came with mine was very comprehensive. Much of this kit seems to have been upgraded for reliability. Many of the screws on the engine have been replaced with hardened ones. The petcock has a rubber O ring on it that I have not seen before. The box was packed well and nothing was missing or damaged. This kit is definitely a step above similarly priced, unbranded versions that you find on ebay. So please, unless you have the necessary skills to build and maintain a motorized bike, do not buy this kit and certainly do not rate it poorly because you didn't know what you were getting into. If you know what you are doing, this is a great buy. To reiterate:YOU MUST ENJOY BUILDING AND MAINTAINING ENGINES FOR THIS TO BE WORTHWHILE.

The first thing I have to say is know what you are getting into before you order a kit like this. When I saw this kit, and numerous others just like it (I am convinced that all of these kits come out of the same factory in China), I knew immediately that the statement in the description about this being able to be installed within a few hours was total BS. The photograph of the kit contents is accurate, and having already assumed that, I knew that this thing wasn't going to go together in an afternoon. I do a lot of hobby work, especially with things made of metal, and I have very realistic expectations about such things. I am a firm believer in Murphy's Law, and in a way, I embrace it. I don’t mind spending hours in the shop with my metal and saws and files and torch tips and grinding wheel and drill press. Is this you? If not, think twice about ordering a kit like this.I suppose it's possible you might get lucky and have this thing fit your bike perfectly right off the bat, but I would not count on it. Here are some issues I ran into, and I am not the only one:The sprocket rag joint is tedious to install, and takes a good eye and quite a bit of patience to properly align. The motor mounts did not really fit my frame correctly. I could have bolted them on as it was and it probably would have worked fine, but the fit would have produced pressure points that made me nervous. I fabricated a metal bracket, as well as a custom spacer made from JB Weld and mild steel plate to form really solid motor mounts that will stay in place unless I desire otherwise. This kind of work is not for everybody.As for the other stuff, you need to be somewhat mechanically incline and patient. The YouTube video is pretty good, but you need to move slowly and consider every step. DON’T use pliers and vise grips as shown in the video. This struck me as being outrageously bad practice. You will require open end, box, and ratchet wrenches between 10 and 14 mm, and having a small crescent wrench around is not a bad idea either. In addition to this, a single multi screwdriver will get you by, and some nut drivers will help, too.Having said all of that, I did get the thing on my bike, and it works great! I’m still in the break-in period, and I am having a hard time restraining myself from digging into the throttle. I have a very accurate speedometer, and keeping this thing below 16 miles an hour requires quite a bit of restraint for me. I only weigh 140 pounds on my heavier days, and at that speed a little twist on the knob accelerates quite impressively. I have no doubt I could easily kill myself on this thing. Yeah!I would not mount this kit on anything but a sturdy mountain bike with thicker spokes and good brakes.Of course, I have a few photos.I hope that helps!

As others have stated, it is important that you know what you're getting in to with one of these kits. It is not plug and play. The assembly is neither easy nor straightforward. You're going to need a lot of tools and some extra hardware to make this work. This is the case with all cheap 2-stroke kits, not just this one.That out of the way, this kit is pretty good. It came well packaged and nothing arrived damaged, despite Amazon's/ UPS's best efforts. The kit comes with a ton of "just in case" hardware and actual printed instructions, which is nice.I installed this on a standard, single speed, 26" cruiser bike. The install took about 10 hours, but could have been done in less. Install was mostly as expected from following online video instructions. The kit comes with a few "upgrade" items like an o-ring for mounting the carburetor to the intake (highly recommended) and a bracket to support the exhaust. The spark plug gap was correct out of the box.I did have the following problems:1) The clutch seized for no apparent reason. This was remedied by disassembling and then reassembling the clutch.2) The fuel filter leaked right out of the box. I ended up buying another off amazon 10/$10.3) The rear sprocket ended up slipping about 3 miles in. I replaced it with a hub mounted version.4) The wire colors in the directions do not match what is shipped. This wasn't a problem, just sort of annoying. Similarly, the oil mix instructions differ between the manual and what is shown on the Amazon listing.On first start the engine had good compression and spark. It was hard to start at first, but apparently that is a very common problem.Overall I am happy with everything so far. I would recommend the hub mounted rear sprocket and a spring loaded tensioner as upgrades to this kit and be prepared to replace the fuel filter is it start leaking, but everything else is serviceable.