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

[Sketch]

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). 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...

 

[Sketch]

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

 

[Turtle Tedd]

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

 

[Turtle Tedd]

I that vendor you were buying from still around?

 

[KeepOnKeepnOn]

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.

 

[Sketch]

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

 

[Sketch]

Ok I see the conversion kit on this page: http://www.choppersus.com/store/category/6/32/Bottom-Brackets/

Thanks

 

[KeepOnKeepnOn]

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.

 

[srdavo]

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

to answer your question:

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

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.

 

[Sketch]

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