no power

[56b1093]

I am having some trouble with my 56b hummer. It has little to no power in 2nd and 3rd gear. I have had the carb apart and cleaned and have been playing with the adjustments on the carb with little to no success. I am only able to get about 30mph out of it and it has a hard time with even the smallest hills or inclines. Any help is appreciated.

thanks

[Mutt]

recent bore and new piston/rings?

[250_Sprint]

Are you getting enough fuel flowing?
Make sure the petcock feed pipe is not clogged in the tank.
Make sure the petcock is not being obstructed internally.
Try running the engine in neutral (no load) and take notice of engine response with throttle grip rotation changes. Open the throttle slowly like you are riding the bike. Notice if the engine is responding better or the same without a load.

Remember, this is a wet clutch design and if the friction plates have had a chance to dry out some, they may not be able to grip as they should when wet. The clutch may be slipping until the friction plates saturate up again.

Has the clutch been adjusted?
Do the clutch friction plates need to be replaced?

Checking on what you have or you may get frustrated.

-good luck

[houtzv]

Also, check your brakes. My 125S was sluggish because the front brake was dragging. I put a spacer in behind the brake carrier and that removed the excess friction. Now I just need to ride it again.

[Backyard Bob]

I agree with all of the above. I'd add you do a compression test and look for leak down (ring/piston wear) Mutt can guide you on that.

[56b1093]

I have good gas flow, clean tank, new gas line, cleaned carb. Bike runs good in the shop. Throttle response seems good, idles good. Tonight I rode it again and noticed that every time I stepped on the brake, the engine stalled. As soon as I let off the brake the bike would start again. Coil issue?

[250_Sprint]

With the transmission in neutral, start and get the engine warm enough so she idles on her own. Step on the brake pedal. Does the engine die? This duplicates the problem on the road.
If it does die, remove the brake light bulb, start the engine and step on the brake pedal. Does the engine die? If so, the bulb is good.
Now disconnect the two wires at the brake lamp switch, start the engine and touch the two brake switch wires together. Does the engine die? If so, test the brake lamp switch for an internal short. Use a multimeter or a light bulb and power source do run this test.
If the brake lamp switch tests good, there may be a short in your harness. Visual scrutiny and multimeter are the only test procedures and it can be time consuming.
You may also have a short in the wires of the magneto assembly. Again, time consuming.

Of course there is one more suggestion and you do this at your own discretion: don’t use your rear brake. lol

[56b1093]

I pulled the taillight bulb this morning and now the bike does not die when the brake pedal is pushed. However, the bulb looks to be good. Ill test with a meter after work today. Once I get that figured out, I just have to deal with lack of power. I think a compression test will be next.

thanks for the help.

[250_Sprint]

If you haven’t already done so, go to the HHC site and click on How To Restore in the banner at the top of the page.
Scroll to the bottom of the How To Restore page down to PART 3 - THE DETAILS.
About 1/2 way down is Chapter 66. This is Wiring. Click on wiring. Then choose the flavor of wiring diagram for your model.
Save a copy.
Study the copy.
The Hummer diagram is fairly simple to read.

While looking at the wire diagram for the Hummer (Figure 5B-5 on page 5B-8) the + of the ignition (spark) coil is a yellow wire which attaches to a points ground which is also a yellow wire going to the bottom coil of the magneto.
Check your bikes wiring against the Hummer diagram.
Another place to check for continuity is where wires are attached to the points.
Make sure the attached wire(s) are properly insulated.
At the screw there should be some non-conductive washers. There should also be a small non-conductive ring on the screw where the screw passes through the hole of the points body. If the ring is broken, it may cause a short.
The parts book does not show the points screw insulators in an exploded view, so when you disassemble, pay attention so you assemble correctly.
If the ring is broken or not there, a suggested alternate is a short piece of heat shrink placed on the shaft of the screw against the head of the screw and approximately the length of the gauge of the points body. It may take a few attempts to get the correct length but time spent here allows (s)miles down the road.

[56b1093]

Anyone know how much compression the b engine should have?