A mods/fixes checklist for installing a Honda GXH50 frame mount kit

Discussion in '4-Stroke Engines' started by Sketch, Nov 19, 2009.

  1. Sketch

    Sketch Member

    In a few days I'm going to order my GXH50 frame mount kit from bicycle-engines.com. I've done a 2 cycle kit before so I have some idea how you end up coming up with custom solutions and improvements.

    I have reviewed many of the posts here (and done my own research elsewhere) and it would be useful for me, and hopefully others in the future, to compile a summary list of issues and the general idea of the solution (or where to get more info). :idea: I will start the list and hopefully I can get help from some of you to help complete it. I will edit in the additions/changes that are posted.

    [In my case, I'm ordering the kit itself and the vintage fuel tank, so I'm not looking at dealing with any fancy customizing, just getting the basic kit working good and considering several improvements]


    Checklist for Honda GXH50 Frame Mount Kit

    Ordering the Kit
    bicycle-engines.com has about the best prices (no tax, no shipping, $499) and they seem to have a good review by people on this forum who have used them. Of course, there are many other retailers for the kit.

    Installation Manual
    The manual from bicycle-engines.com is "ok"... Not all issues are addressed and it's generic to HuaSheng/Honda. I have not found a GXH50-specific manual, but a somewhat better manual of the same type is available at the wholesale site for the kits: http://www.grubeeinc.com/USA/Stage III.htm

    GXH50 Owners Manual
    See the third post on this thread: http://www.motoredbikes.com/showthread.php?t=11224&highlight=GXH50

    General Tips
    Couldn't hurt to review this compilation of info and topic references:
    http://www.motoredbikes.com/showthread.php?t=17401&highlight=GXH50&page=2

    Throttle Issue
    Apparently the factory throttle/spring mechanism on the engine doesn't provide enough force to pull back the throttle after twisting the throttle grip handle. There are multiple solutions that have been discussed:
    http://www.motoredbikes.com/showthread.php?t=7744&highlight=GXH50
    and
    http://www.motoredbikes.com/showthread.php?t=22690
    also discussed here:
    http://www.motoredbikes.com/showthread.php?t=13962&highlight=GXH50

    Exhaust Pipe Mounting
    Using the exhaust pipe provided with the kit, it appears most people add a frame-mounted support. I've seen it in many photos but haven't seen where people have discussed the easiest way to make and attach the mount. (Anyone?)

    Front Pedal Sprocket
    I haven't read about this anywhere, including in the sales website literature, but from photos I can tell that when installing the kit (specifically when you install the wide pedals shaft) you replace the front sprocket with a single sprocket - such that on a 18 or 21 speed bike you lose your front gears. No biggie to me, just thought it's worth pointing out.

    Engine Break In
    The discussion of break in (http://www.motoredbikes.com/showthread.php?t=21085&highlight=GXH50) seems to have ended up with Honda's official position that there is no break in required. However, taking it easy for the first 10 hours or so, and changing the oil during that period would seem to be a good idea. And, do not run at idle or constant speed - varying speeds distributes oil better.

    Leaking Carb Problem
    Sounds like a few people ran into this. It's discussed here: http://www.motoredbikes.com/showthread.php?t=21711&highlight=GXH50

    Safety and Maintenance Tips
    Here's a long thread with some humor but also with lots of very practical advice: http://www.motoredbikes.com/showthread.php?t=9519&highlight=GXH50

    Adding a Fuel Filter
    Is recommended...

    Switching to Heavy Duty Axle with Drum Brake
    This is a nice idea, but sounds like a bit of work. The HD Axle kit is available from many of the kit vendors.

    Problems with Starting the Engine & Low Oil Sensor
    Sounds like a few people have run into problems getting the engine started. This thread has some good diagnostic steps and discusses the Low Oil Sensor which can potentially kick in at the wrong time:
    http://www.motoredbikes.com/showthread.php?t=17401&highlight=GXH50&page=2


    and I'm sure there's more...
     

  2. Sketch

    Sketch Member

    um, why aren't my url's url-ing? what did I do wrong...?
     
  3. Turtle Tedd

    Turtle Tedd Member

    Sketch...some one here must know..I would sure like to read all that info you have compiled in one post
     
  4. Turtle Tedd

    Turtle Tedd Member

    I that vendor you were buying from still around?
     
  5. The motor/tranny is very wide, so the wide cranks that come with the kit are necessary. If you have a one peice crank (most cruisers) you will need to buy a square taper bottom bracket conversion. That set me back a week. They are available at choppers-us. The cranks only have one ring so you will lose front deraileur shifting if you currently have 3 rings.
    The gearing in my gearbox was horrendously loud...unfixable though. Proper lubing and a peice of cardboard inside the box or foam rubber on the outside has helped some people, but not mine. Also the gearing is so low that a 36t sprocket for the rear wheel was necessary for any decent speed.
    The throttle return is a little inadequate. I have dealt with it by making my throttle cable well oiled and as kink free as possible, but it does lead to high idleing, really a not big issue. Mine is actually a huasheng kit which came with useable throttle mount no mod necessary.
    an extra attachment for the exhaust is easy if you have a welder, which is what I did. You could go funky with bailing wire or plumbers tape though. Some kits actually come with a bracket. I'm not sure it is necessary but all the weight of the long/heavy exhaust rests on two very small bolts. I personally felt it was needed without ever actually trying to go without.
     
    Last edited by a moderator: Nov 21, 2009
  6. Sketch

    Sketch Member

    Hey KeepnOn,
    I have an older mountain bike with what looks like a one piece crank. If it's bent vs. screwed in at the 90 degree angle out by the pedals, that means it's one piece, right?
    I was not aware that I would have to order a conversion kit...
    Thanks
     
  7. Sketch

    Sketch Member

  8. That is correct. A 3 peice crank set gets the cranks bolted to the bottom bracket (has a bolt at the base of each crank). A one peice crank is one continuous peice of metal that forms both cranks and the bottom bracket so it does not need to be bolted to the bottom bracket. Actually there is another way to do it and it is supposed to be stronger... there is an extra wide one peice crank which is made but I have not tried it or know where to get them.
    When motorizing a cruiser another serious consideration is that a front brake is absolutely positively mandatory! A rear coaster brake as your only brake will not cut it. The seemingly easy route is to drill a hole in the fork and mount a caliper brake, wrong, caliper brakes are basically worthless, I went this route. You need a drum brake wheel, expensive but easy and stylish. Or a fork with mounts for V/Cantilever brakes, cheap because its easy to find a donor bike to take the parts off of but generally lose style points because it doesn't look vintage (you can buy springer or chopper forks now with brake mounts). Obviously the same could be done with a disc brake but finding an abandoned disc brake set up won't start happening for a few years yet. This is not specific to the 4 stroke kit though.
     
  9. srdavo

    srdavo Active Member

    Sketch,
    I like this thread & what you are doing here.
    Good Info !!

    to answer your question:
    you can't post links until you are here 30 days and have 30 posts. this helps us fight the one-time, wham bam spammers.

    in the meantime, we can copy & paste the links into a new tab.
     
    Last edited: Nov 21, 2009
  10. Sketch

    Sketch Member

    srdavo, ok I see I can fix it in 30 days maybe. The other thing I assumed when I started this is that I could roll up the additional info learned in the thread (already got good stuff from keepnon) into the top post...but I don't have edit ability for my own post. Do I get that at 30 days also? Thx
     
  11. Sketch

    Sketch Member

    re: pedal crank

    This is what had me confused (would confuse anyone):

    Being a pragmatic planner would lead a person to reading the installation instructions before ordering. However, the installation instructions at bicycle-engines.com states:

    "It is very important that the bike have a one-piece crank. Bicycles with cartridge type bottom brackets or three-piece cranks will be very difficult to use with the extra-wide one-piece crank included with the Whopper Stopper kit."

    I re-checked the instructions at the grubee website and found that apparently they have both types of cranks available:

    "Large bottom hole, approx. 52mm dia. ID is needed to accept our one piece pedal crank. Small bottom hole bikes can use our 3 piece wide pedal crank"

    Therefore the question is, which version of the kit am I getting?

    I emailed bicycle-engines.com to find out.

    In the mean time, I placed an order for the conversion kit. I will return it if I don't need it.
     
  12. Pablo

    Pablo Motored Bikes Sponsor

  13. Sketch

    Sketch Member

    I appreciate the heads up Pablo. I already determined that I don't need the conversion and successfully cancelled the order. In the future I will check out your site and the other sponsors first.
     
  14. Sorry about that, I thought pretty much all the 4stroke kits came with the 3 piece style wide crank. I actually got mine from bicycle-engines like you did too.
    Definitely check out Sick Bike Parts they have stuff you dont even know you want yet. Like a 415 chain 1/2 link that will allow you to make your chain the perfect length so you can do away with the noisy/ugly/cheap chain tensioner. A dirt cheap part that makes all the difference which you will not be finding at your local bike shop. Definitely no diss meant to SBP or the others by sending you to choppers-us, I just got mine there so I threw it out there and I wasn't aware SBP carried the bottom bracket conversion.
    Another rather nice modification is a freewheel sprocket for the drive sprocket on the gearbox. You could pretty much call it a necessity if you ever plan to pedal without the motor, assuming all the gearboxes are as hard to turn as mine is!
     
  15. Pablo

    Pablo Motored Bikes Sponsor

    No problem. This is a good thread.
     
  16. Sketch

    Sketch Member

    Looks like my links work if quoted by one of you...Pablo or KeepnOn how about quoting my entire first post so the links can show??? (for now, I still hope to edit the first post eventually)
     
  17. Sketch

    Sketch Member

    Checklist for Honda GXH50 Frame Mount Kit
    Revision 1

    Ordering the Kit
    bicycle-engines.com has about the best prices (no tax, no shipping, $499) and they seem to have a good review by people on this forum who have used them. Of course, there are other retailers for the kit.

    Installation Manual
    The manual from bicycle-engines.com is "ok"... Not all issues are addressed and it's generic to HuaSheng/Honda. I have not found a GXH50-specific manual, but a somewhat better manual of the same type is available at the wholesale site for the kits: http://www.grubeeinc.com/USA/Stage III.htm

    GXH50 Owners Manual
    See the third post on this thread: http://www.motoredbikes.com/showthread.php?t=11224&highlight=GXH50

    General Tips
    Couldn't hurt to review this compilation of info and topic references:
    http://www.motoredbikes.com/showthread.php?t=17401&highlight=GXH50&page=2

    Throttle Issue
    Apparently the factory throttle/spring mechanism on the engine doesn't provide enough force to pull back the throttle after twisting the throttle grip handle. Solutions include oiling the cable, eliminate tight bends, and create a custom throttle/spring assembly. Discussed here:
    http://www.motoredbikes.com/showthread.php?t=7744&highlight=GXH50
    and
    http://www.motoredbikes.com/showthread.php?t=22690
    also
    http://www.motoredbikes.com/showthread.php?t=13962&highlight=GXH50

    Exhaust Pipe Mounting
    Using the exhaust pipe provided with the kit, it appears most people add a frame-mounted support. I've seen it in many photos and personally plan to improvise with a trip to the hardware store.

    Front Pedal Sprocket Is Replaced
    I haven't read about this anywhere, including in the sales website literature, but from photos I can tell that when installing the kit (specifically when you install the wide pedals shaft) you replace the front sprocket with a single sprocket - such that on a 18 or 21 speed bike you lose your front gears. No biggie to me, just thought it's worth pointing out.

    One Piece -or- Three Piece Crank?
    The kits can apparently come with either the one piece or three piece extra wide replacement crank. You have to find out which one your vendor sells and may need to buy a conversion kit if you don't have the corresponding type on your bike.

    A kit for converting to a three piece crank is at http://www.sickbikeparts.com/catalog/index.php?cPath=23

    Chain Tensioner
    The tensioner that comes with the kit has a disappointing plastic roller. I have seen two alternatives. (1) get a toothed gear for the roller online or at a local go-kart shop. (2) adjust the chain just right and do away with the tensioner.

    I did the second option with my 2-cycle kit - it required removing 2 or 3 links from the chain. To get the exact length needed, you may need a 1/2 link, available here: http://www.sickbikeparts.com/catalog/product_info.php?products_id=68

    Fuel Tank Preparation
    The Grubee installation guide suggests the tank should be "Kreemed" before use. Elsewhere I have seen it stressed that you should air blow the tank clean thoroughly before using it. The point being that the carb is very sensitive to debris so every precaution should be taken.

    Adding a Fuel Filter
    Is recommended. Here is one at Sick Bike Parts:
    http://www.sickbikeparts.com/catalog/product_info.php?products_id=53

    Engine Break In
    The discussion of break in (http://www.motoredbikes.com/showthread.php?t=21085&highlight=GXH50) seems to have ended up with Honda's official position that there is no break in required. However, taking it easy for the first 10 hours or so, and changing the oil during that period would seem to be a good idea. And, do not run at idle or constant speed - varying speeds distributes oil better.

    Switching to Heavy Duty Axle with Drum Brake
    This is a nice idea, but sounds like a bit of work. The HD Axle kit is available from many of the kit vendors. Reviewed here: http://www.motoredbikes.com/showthread.php?t=7026&highlight=Heavy+Duty+Axle

    Consider a Higher Gear - Other Sprocket Sizes
    The kit comes with a 56 tooth sprocket, which people report equates to a fairly low gear. Fewer teeth gives a higher gear, which goes faster but requires more pedaling to start out. Several sprocket sizes are available.
    Discussed here: http://www.motoredbikes.com/showthread.php?t=11680

    Problems with Starting the Engine & Low Oil Sensor
    Sounds like a few people have run into problems getting the engine started. This thread has some good diagnostic steps and discusses the Low Oil Sensor which can potentially kick in at the wrong time:
    http://www.motoredbikes.com/showthread.php?t=17401&highlight=GXH50&page=2

    Leaking Carb Problem
    Sounds like a few people ran into this. It's discussed here: http://www.motoredbikes.com/showthread.php?t=21711&highlight=GXH50

    Safety and Maintenance Tips
    Here's a long thread with some humor but also with lots of very practical advice: http://www.motoredbikes.com/showthread.php?t=9519&highlight=GXH50
     
    Last edited: Nov 23, 2009
  18. Pablo

    Pablo Motored Bikes Sponsor

    TEST
     
  19. Sketch

    Sketch Member

    Cool, thanks Pablo!
     
  20. TREEWK

    TREEWK Member

    Bicycle-engines.com. I Like The Looks Of The New 4g Belt Tranny Kit For $399. With Free Shipping. If You Don`t Like The New Belt Drive You Can Buy The Other Tranny For $120 Later. Then You Would Only Spend 20 Bucks More And Have Both Trannys. Cogged Belts Are Tuff. They Run Car Camshafts With Them, Thats Tuff In My Book. Just A Thought. I Have Been Running My Titan/hs (same Engines, I Have Them Both) For Two Months And Never Have To Adjust Anything Since Day One. They Idle Perfect, Never Hesitate. Ron
     
Loading...