Hate to say this but h.t. motors are not something meant to be raced like a ninja

Discussion in 'Performance Mods' started by plinko, May 18, 2010.

  1. plinko

    plinko Member

    People!!! I am tired of reading posts where people whining about their h.t. motors won't go past 35 and tear up.What do you expect for 100 to 150 bucks and from a chinese plant with no quality control.And I feel like by the time you rebuild a china girl with all these souped up pistons,reeds,And so on.You still have a motor with questionable quality.And end up spending more on them than If you just saved up and bought a morini or a good ezm quality 4 stroke.I understand some people like to tinker on stuff.But many people do not have the time,tools,or skills to do so.So why people whining when their cheap motors have mechanical probs at 500 to 1000 miles running them at full throttle all the time and then complain when the thing tears up?I run my pk80 all stock at 25 mph like Intended and have 1100 miles on It with only a piston ring change and sparkplug change.Wanna run something beyond It's means of doing so? expect problems.Even quality race motors.especially 2 strokes require constant weekly maintenance of gaskets and tightened nuts and bolts or they will tear up also.Treat your motor right and respect It's limits.And It will respect you.Plain and simple.P.S.motored bikes are not kawasaki ninjas and It's unreasonable to try to make them so.

  2. Esteban

    Esteban Active Member

    You can look back over my posts years ago, where I stated that the more motorbike kits on the road with owners " souping " them up to go faster speeds,[ & louder exhausts ] the sooner we will see restrictions & laws changed against having one.
  3. 210061741

    210061741 Guest


    It's the dudes going down the street with noisy weewackers smoking to high heaven that draw negative attention.

    I get more respect for my high performance build than any of the unsafe builds rollin around town.
  4. plinko

    plinko Member

    Agreed esteban.All this negative attention starting to get noticed by authorities.Cops ticketed a friend of mine for doing 32 mph on a stock kit.I personally think 40 mph should be the law on backroads with semi's rolling by and no curb or shoulder to roll on.But,All the negativity starting to get bad on these.And you are right on hopping these up and personally,I agree with you.I look for these and mopeds to become Illegal In my lifetime If things do not change both on the parts of the federal government,e.p.a.,And consumers like myself.
  5. plinko

    plinko Member

    I agree with your statement. but,It falls on our shoulders to lobby and sign petitions to protect our rights.There was a time In this country where you could ride a whizzer bike with a 138 cc motor without license or registration.Texas already passed a law prohibiting motors over 40 cc's
  6. 210061741

    210061741 Guest

    Well yes very much true.
    Fortunatly for me and fello riders in erie someone was arrested a long time ago.
    They took the case to court and proved the bike was legal.
    Since then we have been free to ride.

    I was stopped only once in 2 years of riding constantly.
    Even in the snow through the winter.

    Never been ticketed and never got any negative comments about my bikes.
    Most people stop me to buy it.

    Anyway yes something needs to happen.
    There changing the laws cause there not making any money off of it.
    There really is no other reason.
    The licence bit came about because of all the DUI individuals riding motored bikes.

    But what this hobby needs is something great.

    It needs a Fisher Engine that gets 300 to 500 miles per gallon and has low emmissions.
    Iv'e been working with them to turn this into a reality.

    Even a moped that got 500 MPG would be impressive enough to get the support of Green Lobbyist as well as media attention.

    So it's all about efficcent technology....got to beat them at there game.

    Something that is that efficcent can't be denied.

    It is more than speed for me.
    It's a way of life.

    It's never hoping into a car and being classifyed as normal by society.

    It's about the freedom of the people.

    The freedom to choose more efficcent lifestyles and Break free from the cost of ENERGY.

    Energy rules the world because society lets it.

    So thats my story...so thoose who say this is just a hobby.

    To me it's much more than a hobby.

  7. plinko

    plinko Member

    I ride 24-7 snow,rain,heat,wind.Only time I pass Is lightning.I am more than a hobbyist.But even those who do It for hobby or those die hards like you and I need to come out with some Innovative technologies and band together to preserve our rights and moped owner's rights since we fall under the same category.Put all differences aside and peacefully fight for a wonderful cause.Or I fear there may not be anything for the hobbiest or die harder like ourselves to enjoy or show our children.
  8. plinko

    plinko Member

    Bt the way.Our posts are deviating off course.My post here was for trying to get ninja like performance of a ht and overabuse of a cheap motor designed to run at 30 mph tops.These posts we are making now should go Into my why not protest section.
  9. Fabian

    Fabian Well-Known Member

    Quote Esteban: "You can look back over my posts years ago, where I stated that the more motorbike kits on the road with owners " souping " them up to go faster speeds,[ & louder exhausts ] the sooner we will see restrictions & laws changed against having one."

    Yes, i'm in the same boat about the issues that more of these motored bicycles in the wrong hands will bring to those who desperately need a motored bicycle as their only means of transport.

    I was seriously harassed by one of the moderators on the other site (who has now made it his personal vendetta to try and get me permanently banned) for being vocal about a kid in the Victorian town of Mildura (Melbourne, Australia) having his day in court after the police stopped him; gave a ticket for riding at 50 km/h (30 m/ph) without pedalling, then summoned him to attend court on traffic charges, relating to his motorised bicycle.

    I called the kid a fool (ok, i called him an idiot) for complaining that the police are taking him to court.
    A bicycle is designed to be operated with pedals - obvious from a police officers perspective, and how many cyclists can ride at 50 k/ph on flat ground without pedalling. At the end of the day, a police officer's job is to get a conviction, and they pick on people who are least able to defend themselves, not to mention a hassle free day in court for the police prosecutor.
    This is the second high profile case where police are now asking the traffic authority for clarification of the rules regulating motorised bicycles, and potentially, the anti-hooning legislation could allow police to confiscate motorised bicycles, and have them crushed.

    This one kid has basically wrecked a practical form of motored bicycling for those people in Victoria who desperately depend on such transport.

    If you look at my posts on the issue, i've advocated the policy of staying under the radar; making sure you are pedalling at "ALL" times, and having a standard looking engine.
    As soon as you put race tuned expansion pipes on a bicycle or noisy exhausts, you've just raised your profile in a very negative manner.
    In my case, i get leg cramps on a long journey from pretend pedalling and try and maintain a 30 k/ph speed difference between my motored bike and cars, and try not to exceed 40 k/ph on flat ground, but only do so to stay well and truly under the radar, and in 6,000 kilometers of riding, i've never been pulled over.

    Last edited: May 20, 2010
  10. 210061741

    210061741 Guest

    ok lets get back on topic here.

    And Fabian you were 1 of the first begging pirate to take a prepayment for a high performance Engine.

    We all want a good quality engine.

    The bottom line is unless it's 25cc 2 stroke or a 50cc 4 stroke a high quality engine will have all the bells and wistles along with it. With quality comes power and with power comes speed.

    Is or can a HT engine ever compare to a NINGA NO NO NO.

    So here are the facts.

    The chineese engine is cheap the components are cheap and the port timing is setup in a manner that restricts the performance of the engine.

    To further restrickt the performance a very restrictive exhaust is also place on the engine.

    So due to the out of box configuration the engine components can handle the meager performance. And most of the time due to the lack of sound engineering principals it's componets fail prematurly. The ignition system lacks tuneability and the accuracy of the timing is dependand on how accuratly the Cases are drilled to mount the coil.
    The drillings in the coil. The accuracy of the crankshaft where the magnet presses on. The accuracy of the bore of the magnet and most importantly the accuracy of the keyways cut in the magnet and the crankshaft. Then throw in the variance in the stroke and the center to center distance of the connecting rod + the slop in the bearings and the misalignment of the cases. and you have 1 big mess.

    As Fabian has clearly demonstrated the problem of pre-ignition and of retardation shows up in the big end bearings.

    So what do we have here???
    We have potential for the individual that desires to put the time in to clean up the mess.

    First everything must be dissassembled cleaned and inspected.

    All of the Bearings need to be replaced except you cannot change the Big End Bearing because it's an odd size.

    But you can get high quality Mainbearings, Countershaft Bearings, and a high quality bearing for the piston wristpin.
    The sealed mainbearings do a much better job of sealing the crankcase and actually double seal it.
    First the pressure has to get past the bearing seal then it has to get past the crankcase seal. So that extra bearing seal is great cause it takes alot of the strain off the crankcase seals. We all know the crankcase seals are **** and need all the help they can get.

    The quality bearings can handle much higher loads and greater RPM's.
    The quality bearings also have less horsepower robbing friction.

    The bearings are the heart of the engine.

    So lets talk about the body " the CrankCases "

    The crankcases are thin but all and all not too bad.
    The aluminum alloy is brittle so it resist flexing but breaks easily and threads strip easily.
    But the brittleness actually works to our favor.
    So long as the bearings are in good shape and the alignment is pretty close the forces that are applied to the crancases are in a compressive manner. The alloy can handel a high dose of compressive stress.
    Now being brittle if the alloy is put under Tensile stress or shearing type stress it will break. The cases are also reinforced in the areas of the bearings.

    Provided the cases are machined as intended the bearings are a light press fit into the cases. Which is good for alignment.
    Now there is a bit of clearence between the shafts and the bore of the bearings but it's a close running fit. Point being.

    There a 3 alignment features of the cases.

    #1 there is a ring machined on 1 case half and a counterbore to accept that ring on the other case half. When you snap them together you have positive location to the center of the bearings. It's a tight slip fit.

    #2 when inserting the crankshaft into the bearings it also reduces the misalignment of the cases. The crankshaft provides the 2nd locational feature.

    #3 The countershaft or drive shaft provides the 3rd point of location. Also a tight slip fit into the bearings.

    The combination of these 3 features provides decent alignment of the bottom eng.

    The trick to geting things as good as possible is pretty easy.

    Assemble the botom end but leave all of the case screws loose.
    Put the piston assembly on the connecting rod and slide the cylinder on the studs.
    Dont use any gaskets at this point in time.

    Put the head on and tighten the head bolts like normal.

    Since all the case screws are loose this will pull the crankcase mating surface into contact with the cylinder.

    This aligns the case halves to the cylinder a good as the machining allows.

    Now tighten down them case screws.

    Pull the top end off and retighten the case screws.

    Now assemble the engine as normal.

    At his point the engine is in pretty good shape.

    If you had cut the ports to the proper configuration before you assembled the engine your in great shape.

    With the proper porting and a good breathable exhaust then engine will reliably run at 10000 rpm. A breathable exhaust dosen't have to be loud. It has to breathe easily.

    Now the only crappy parts left of the engine is the ignition and thin crome plating of the cylinder.

    but hey for $100 it's not too bad.

    So can a HT be a NINGA. NO

    But it can reliably produce 5 to 6 hp at 10000 rpm and that i know from doing it.
  11. fm2200

    fm2200 Member

    I live in a densely populated area, and in the two years of riding around I'm just glad that there is hardly anyone interested in getting a gas bike. Here you can't build your own mb they will only let you register with the DMV mb's approved by the state, manufacturers that they believe make a safe mb's. That drives the cost of getting a gas bike way up from the guy that just purchases a kit and makes his own. The younger guys are usually reckless and want to get attention good or bad. I just hope that proliferation of mb's doesn't rob the law bidding guys from this form of recreation.
    Last edited: May 20, 2010
  12. Fabian

    Fabian Well-Known Member

    Rich, i want a "standard looking" engine that gives a lot more low and mid-range torque.
    I think i've been fairly consistant on that theme, also the reason why i want a standard look exhaust system, like an x-can system.

    Massive amounts of extra torque at low rpm; with mild power increase and an almost silent engine - that's my requirement to fly under the radar.

  13. Fabian

    Fabian Well-Known Member

    Rich, you can also go the route of changing the crankshaft pin to 17mm, from the standard 16mm, and run a better caged needle roller bearing measuring - K17 x 10 x 21

    The advantage of doing so, is to be able to offset bore the pin hole in the crankshaft halves, so giving an extra 1mm of stroke, or you could use an 18mm offset pin bore for 2mm of extra stroke, by line boring the connecting rod to 22mm and having it case hardened again.

    I went through all these options a long time ago and in the end the best method was to use a Suzuki LT80 connecting rod, which has a larger big end diameter but the same centre to centre length as the standard Happy Time rod.

  14. plinko

    plinko Member

    :rolleyes7: Way off topic on this thread. Way off!!! What the heck does this thread opening post have to do with building a ht engine?Please post In the right forum,open your own,comment to the original thread here,Or don't reply.But please fabian and fm2200.Keep It on the original thread.Or move It.:shout:
  15. plinko

    plinko Member

    Wow!!!:bowdown: /your knowledge Is grand and no disrespect to you.But I get 5 to 6 hp from a stock grubee gt5 66cc without breaking It down and getting all complicated with custom parts.And I figure for that trouble you put Into that I would just buy a morini 6 to 9 h.p. motor all set up for performance and be done with It.But,I do respect the fact you take your way of life seriously.Working at a foundry allows me the option of making molds of my h.t. with quality aluminum.and not have to worry about cracking or flexing either one.Nice thing to do If you got the time.But,I would rather just buy a morini or motobecane motor and have the quality and performance already there.
  16. 210061741

    210061741 Guest


    Seriously if you put the stock motor on a dyno i doubt you are getting 5 to 6 hp.
    In all reality the Grubee Engines to meet EPA run 2.5 / 3hp out of the box.
    But i guess i could be wrong.

    If that is the case then my engine pushes far beyond 5 to 6 hp.
    It pulls like a KX-80 from 0 to 40.

    I did see a video of a dyno run at 7+ HP and that engine way outperformed anything i have seen on a bicycle.

    I also saw dyno results for another heavily modifyed bicycle engine that came in around 6HP.

    Like i said i could be wrong but in reality i don't think a stock engine will even get 4 HP.

    If you have some data to support the claims that would be cool.
    I'd love to see what my engine really runs.
    The cylinder is modifyed with the reed block intake and the exhaust port is nicly cut.

    Im runnung an 18mm dellorto PHBG and a Bennasar Expansion Chamber that cost $150.00And dont forget i am also running the puch high compression head.

    The HT engines definatly have potential.
    But like you said all and all i got about $500.00 in the engine alone and could have easily built a Motorbecane AV10 Engine with the 3rd transfer.

    I have a Puch Top End Kit thats reed valve ported.
    Came with the gaskets, piston, Wristpin, Pin Clips, and a nice K-Star Nikisil Lined Cylinder.

    I'm going to put it on a ht bottom end for the fun of it.

    Next will be the AV10 and that like you said is a real engine.
  17. 210061741

    210061741 Guest

  18. Fabian

    Fabian Well-Known Member

    Stock engine = 6hp :rofl: :bs:
  19. Porkchop

    Porkchop Member

    It amazes the heck out of me of all the folks on this forum that claim to be good samaritans, but are bent out of shape to build bikes that are illegal in most states on public property. They're the ones that will most likely be responsible for stricter laws and possible banning in the future.
    Last edited by a moderator: Dec 15, 2015
  20. 210061741

    210061741 Guest

    Mann PorkChop

    No offense but maybe we can say it's people that allways bow down to the govt that allow for the rich to run the contry as they like. FOR THE RICH.

    Meanwile over half the income of everybody in the US is taken before you see it by the same lawmakers. Tax on gas Tax on Cigaretts Sales tax Registration and on and on and on.

    This world needs more people to quit being afraid and stand up for what they believe is right.

    Not what someone else says is right.

    And this is a free country. HA. HA HA.

    Your free to do what we say sir. Thats about it.

    It's not anything to do with Speed or Power or illegal bikes.
    It's more like well were not making any money off of it so we need more laws and taxes to get our share.
    So Obama can pass out billions of our dollars to the corporations like AIG to pay allready rich people million dollar bonuses

    Then the rich people use that money to further controll the people that werent born so lucky.

    Screw that.

    If it isn't hurting anyone or putting other people at risk it shouldn't be illegal.

    It's fine to make cars and motorcycles that can go 3 to 4 times any speed limit.
    Of cource the govt is making money there.

    But man if you make a bicycle go over 30MPH your classifyed as a wreckless AXE MURDERER.


    Just a Bunch of poo.