Which engine kit?

Evelyn Hodges

New Member
Sep 2, 2019
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Pompton Lakes New Jersey
I’m sure this is the most frequently asked question, but I need help! There are so many choices of engine kits. I want to get the best engine for my needs. I want to put a engine on a high end mtb. The bike will be used in the woods, mostly on the Cannonball Trail in northern NJ. I would think I would need mostly low end. The bike will probably not be used on the street much, if at all. I do not care how fast it goes, just need the power to get up and over rocks and roots. Any help you can give would be greatly appreciated.
Thanks
 

Jimmy Bloodmaker

Active Member
Nov 24, 2018
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you want to tinker, or just slap and go? for slap and go, i recommend getting a jackshaft and engine kit from one of the vendors tht advertise here. lots to pick from, speed built, torque. i'm sure you'll find an engine. i say jackshaft cause you are gonna want some gear range in the trails. i ride trail and have done both single and multi speed. multi speed is where it's at. single speed is fun too, but you get burnt on steep stuff to easy. if you wanna tinker and build yourself, just get up on amazon or ebay or some where on the web and grab the cheapest motor you can find. then do to the jug as you will, change out bearings and seals and hardware, get a wicked carb, etc. ( some of these guys here can build a wicked engine, and save ya time though).
 

Evelyn Hodges

New Member
Sep 2, 2019
9
1
3
Pompton Lakes New Jersey
Jimmy Bloodmaker, thanks for the input. I pretty much want to just slap and go. I don’t have the knowledge or mechanical skills to do much with the engine. Also, what would be the best size for a rear sprocket for technical woods riding?
Thanks!
 

Jimmy Bloodmaker

Active Member
Nov 24, 2018
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if you are going single speed, on a 26", at least a 48, 52 ( you can always pull in the clutch and coast a single speed down hills, a jackshaft automatically freewheels when throttle is dialed back) would be better. will drop your top end, but you will be able to pull almost any hill at 15 to 20 mph. on a 24" tire, i'd stay with the 44 tht usually comes with the kits. you should contact some of the vendors here and talk with them about what you want from an engine. they will go through their options with you and help you pick the best build for your needs. if you go jackshaft, just make sure you have a 28-34th first gear and you'll be set. since cassette cogs are geared towards human pedaling, it makes a huge difference on gaining speed up a hill. where as real motorcycles have a wider band per gear and would bog down more ( unless its a bike designed for those kind of things). another advantage of a jackshaft is you got all tht gearing for the trails, and still have the top end for on the road. i'm interested in seeing your bike when done. i like to see what other people come up with for trail bikes. i know most riders keep them on the street or pretty tame. i like getting my dirty and flying through the muck. oh an heres a tip to keep ya rolling, make a air filter housing to block mud and water from being sucked in. can be as simple as a butter dish painted up and screwed on to the breather cover. it will save you the hassle i have had to deal with when riding in mud, snow, rain and muck. oh and wear motorcycle gloves and some kind of helmet. you are gonna go down, with saftey gear you'll get back up a lot faster and get back to riding quicker.
 

Evelyn Hodges

New Member
Sep 2, 2019
9
1
3
Pompton Lakes New Jersey
Thank you for your help! Since I am new to the motor bicycling, I basically know nothing. What synthetic 2 stroke oil is popular? Also, you had mentioned a jack shaft. Can the jackshaft be added on later? The jackshaft sounds like it would be great for my needs.
Thanks again!
 

Jimmy Bloodmaker

Active Member
Nov 24, 2018
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i run with 1 ounce blendzall ultra 455 and 2 ounces of lucas land sea and air per gallon. during winter or below 50 degrees, i switch too 3.5 ounces of lucas and no blendzall. i can beat the living tar out of my motors with the first blend. they run great but require a top end cleaning a few times a year, really easy to do. makes everything last a long time. i switch because i'm not sure blendzall 455 formula is cold weather capable. when you first fire up your bike, don;t let it idle very long. do a quick put around the block, like 5-10 mins. then shut it off when it gets good and hot. let it cool all the way to the point you can hold your hand on it and not get burnt. now check you nuts on the motor mounts for tightness. then snug the head bolts ( not crank them down, just nice and snug) in an x pattern. then jump back on it, go for another 10-15 min run, but this time, crack the throttle a few times, like really get on it. do that at few times at least, but don;t hold full throttle any longer then about 15 20 seconds, or till it wraps up good an high in the rpm range. don;t idle to long and vary the rpm around quite a bit the first tank. it's gonna run kinda poopy at first, but thats ok, you're breaking in the engine. setting the rings and the seal pattern on the jug wall, so they seal good and tight. do this till you finish the first tank. second tank, just ride it like ya would, but vary the rpms a bit, never one rpm for to long. then the engine will ask you for a new jet for the carb ( really easy to change, just a phillips screw driver and a flat head), or find the mix of oil and fuel the engine likes with tht jet. you can do tht with the plug readings you'll learn how to take soon. anyway, i could write a book about these engines, yet it's all in this forum written by people far more experienced at this hobby than i.

yes the jackshaft can be added anytime. it's a great piece of hardware to have if they are legal in your area.
 

Evelyn Hodges

New Member
Sep 2, 2019
9
1
3
Pompton Lakes New Jersey
Thank you so much for your help! I’ll post some pics when it’s finished. Also, I am in northern New Jersey, only about 15 miles from the NY State border. Anyone know of a bike builder that possibly can help me with the build?? Will pay
 

Jimmy Bloodmaker

Active Member
Nov 24, 2018
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midwest
Thank you so much for your help! I’ll post some pics when it’s finished. Also, I am in northern New Jersey, only about 15 miles from the NY State border. Anyone know of a bike builder that possibly can help me with the build?? Will pay
there are a ton of posts here on how to build, not to mention on the web. you'll need a few basic hand tools and the knowledge to use them. you will need the notorious 10mm wrench, so i suggest getting a few of those. lol. i could help a bit on from the web on your build. its really not tht hard. the main thing to remember is to line up the sprockets. you can do tht with a cat toy laser pointer and a piece of tape after you put the chain on. basically the tool need is as follows, 2- 10 mm wrenches, a small phillips screw drive, a medium sized phillips, a small flat head and a long medium flat head screw driver, a 3mm, 5mm and 8mm allen wrench, a hammer, a punch the chain pin size ( or you can take the chain to a shop and have it cut to the right size, all on you, it's easy though, just forcing a pin through a hole), and finally a few scraps of construction paper to keep the wheel sprocket centered when attaching it. you just shove them in the space between the hub and sprocket to hold it still when you set it to center. you'll need some teflon tape as well or a rubber oring (3/4 OD chemical and fuel resistant rubber oring, they are like 15 cents at the hardware store) for sealing the carb. thts pretty much all you need right there and you might not even need all those tools.
 

Jimmy Bloodmaker

Active Member
Nov 24, 2018
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midwest
oh and i just remembered you will need to drill a small hole in the handle bars to hold the throttle grip. thats the only need for a power tool. a battery powered drill will do fine for tht.
 

Evelyn Hodges

New Member
Sep 2, 2019
9
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Pompton Lakes New Jersey
Hi again. For a female, I have some good tools and power tools, so drilling a hole in the handlebar for the throttle is not an issue for me. I am a much older female, past motocrosser and mtb racer. I do ok with a lot of the maintenance on my bikes. I will try it myself, but I’m working a lot, so I know it will take me forever to do the build. I’ll give it a try, though.
PS. Love the pig in the front seat on your profile pic!! Awesome!
 

Jimmy Bloodmaker

Active Member
Nov 24, 2018
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midwest
Hi again. For a female, I have some good tools and power tools, so drilling a hole in the handlebar for the throttle is not an issue for me. I am a much older female, past motocrosser and mtb racer. I do ok with a lot of the maintenance on my bikes. I will try it myself, but I’m working a lot, so I know it will take me forever to do the build. I’ll give it a try, though.
PS. Love the pig in the front seat on your profile pic!! Awesome!
age and sex don't mean much in motor bikes, theirs a kid in us all. you either have skills when getting in to motored items, or ya learn 'em. after building my first one, i figured almost anyone can build a simple motored bike ( part of the charm of the happy time). what i like to see best, the customization. people do all kinds of crazy stuff to their bikes. then there are people who invent new things, and on and on i could go. important thing to remember about this hobby, have fun. a super simple engine, that you can make complex if you want, or just ride it as it is and enjoy. saying you did motocross, well you got this hands down no problem, and i'm looking forward to see how you customize. my fav is called green bean, cause her fenders look like green beans and color scheme ( black and green) of the rest the bike matches. my little 66cc city dirt bike. lol. i never did motocross or even raced, besides the " oh crap cops, RUN, COPS!!" kind, but i love bikes. i don't even care what kind, a set of wheels and motor and i'm happy to play. i just hope you didn't get into this hobby thinking you weren't gonna spend a little cash, cause it's worse then crack. you're gonna see all kinds of cool things for your bike. from boost bottles ( to help tht low end by making the intake act longer, but keeping your top end), carbs, to bonified expansion chambers built just for these engines. it's addictive, be careful, it's got me. lol

as for kevin, he's my buddy. currently sleeping on the bed wondering why i turned off his favorite show. i don;t let him drive anymore though ( he's a lot older and bigger, then he was in the pic), he just keeps stopping at ice cream shops and fast food joints. always making us late.
 
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curtisfox

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Dec 29, 2008
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Good advice what JB says, another thought is to get a kit, get it going. Then if you want to tinker and make changes you should start another, that way you can still ride, tinker and make changes on second build........Welcome aboard...............Curt
 
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Evelyn Hodges

New Member
Sep 2, 2019
9
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Pompton Lakes New Jersey
LOL JB! Kevin sounds awesome, my kind of guy, ice cream and fast food! Thanks for the input curtisfox. Any advice or help is greatly appreciated.
I just received the kit today, will start tomorrow on it. I know exactly what you mean about this hobby being addictive. Yesterday, I hadn’t even received the kit and was looking for better parts to upgrade, especially the muffler. The stock one that comes downward under the engine will be gone the first time I do a log grind. I saw some nice performances ones. I’ll do the build first, then start tinkering.
Also, good advice curtis on getting another kit. I do have another mountain bike, one of my former racing bikes. It’s full suspension, so not sure if it will work. It’s tucked away on the basement, haven’t even looked at it in several years.
Also, I have Mavic wheelsets with the flat black spokes. Someone told me to put on my crappy wheelsets. He said the more spokes the better. Is this true? I don’t really plan on doing any “pedaling” mtb ing anymore; motorized is fine with me. So I really don’t care if the wheels get trashed. The Mavic wheels have 18 spokes per wheel with tubeless tires. Yes, when I raced I was considered a “weight weanie “.
Thanks again guys!
 

Jimmy Bloodmaker

Active Member
Nov 24, 2018
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36h hubs and rims, if you plan on having any kind of fun. more is to stiff to handle and side load on trails, 32h ain't all tht bad, 9 hole rag joint is hard to line up in 32h though. you can also get hub adapters, disk break hub and my fav. disk break set up mags, to attach the sprocket on a single speed. some sprockets don't have the disk break attachment holes. an again i bring up jackshaft, which means instead of bolting on a sprocket, you change the crank to a freewheel set up to accept the secondary chain from the jackshaft and just run your back cassette. lots of ways to use what you have, or change to a different rim.
 

Jimmy Bloodmaker

Active Member
Nov 24, 2018
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midwest
for exhaust get a good long headered pipe with an expansion chamber. more low end torque to climb hills and pop wheelies if ya want. most of my low end monsters have headers from 20" to 25" then the expansion chamber cones after tht. they suck up high, but will pull any hill in their path. the jackshaft with tht long header and long intake, man i can real slam through my gears and get to 40 mph fast with tht set up.
 

curtisfox

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Dec 29, 2008
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What JB is referring to jack shaft is called a shift kit, like sick Sick bike parts sell, would be a must on that full suspension bike, as when you hit bumps or the like the chain moves. With a engine kit it would create slack in the chain and and cause bind, or jump off, because the motor is higher then the pivot. Second is if the motor will fit, some will and some no room..........Curt
 
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Evelyn Hodges

New Member
Sep 2, 2019
9
1
3
Pompton Lakes New Jersey
Hi Jimmy, Kevin and Curtis.
I had to do some adjustments to my mtb before the engine kit can go on. I should have it back tomorrow, ( Saturday) or sometime during the week. I am going to do what you had suggested Curtis and I’m getting my old full suspension Pro-Flex out from the corner of the basement and going to get that ready. I do have another set of wheels ( besides the good Mavic wheelsets). I can put the other bike together with all the spare parts that I have and I will see about another engine for that, like Curtis said. The way the full suspension is set up, it shouldn’t get in the way of the engine. I might just get a smaller engine, like 50cc and tinker with that one. One other question that Jimmy had answered before about 2stroke oil. I am leaning toward the Klotz. I used to pre-mix that in my old Honda Elsinore 125 many years ago when I raced MX. Loved that oil!! Elsewhere I had read about Amsoil Dominator. I had good results in the past with the Klotz. I have been out of touch with all this for many years, so no clue what’s popular or in fact any good anymore. I’ll take some pics and upload them soon.
Thanks!
Ev
PS. Jimmy, say hi to Kevin for me!