My son's honda xr 100 seems to be holding back. How can I check for a governor?

Question

My son has a Honda XR 100. It seems to be holding back during acceleration. How can I tell if it has a governor, and how do I adjust it for a little more power? He also has a 1974 Honda Z50 that seems to have more pick-up than his 100.

Answer 1

Probably just needs ignition timing adjusted.

As the rubbing block on the points wear,,Ign Timing gets waay late/Retarded.
Normal Cam Chain & Roller wear causes ign timing to go retarded also.
Power Level falls thru the floor,,while typically displaying no other symptoms of distress.

And valve adjustment.
Hondas valve lash can "wear" EITHER Tighter or Looser---which is Atypical of most engines.
Most motors do one, or the other.
The little Hondas are sensitive to valve lash.
Honda specs are .002",,,use .003" instead--at least on exhaust valve.


The ignition system also has a Centrifugal Advance which occasional gets stuck,
make Certain it's functioning properly.
With the ignition points removed,,,the POINTS cam should be able to be turned with fingers Counterclockwise---then should return freely under it's own spring pressure.


Check also the condition of the ignition points cam.
Occasionaly they'll get rusty which eats away at the ignition points,,which changes timing drastically.

MORE Common is that the points cam becomes Burnished over the years,,,which for odd reasons causes More friction & point rubbing block wear.
Polish it with wd-40 on some 400~600 grit wet/dry sandpaper.
Only go in a motion Around the cam

It probably just needs a simple "tune up".
If it starts and runs and Idles OK---engine Cannot be in too bad of a condition.

If you are handy with tools,,,a basic tune up is simple---
get a service manual and follow the procedure.

Those engines SELDOM run " Bad" when outa tune.
What they do,, is run WEAK.

No Governor,,by the way

Good luck

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

(*****I do NOT recommend fooling with stuff while troubleshooting.
Everything should be functioning Properly BEFORE doing any modifications.

However,,,one simple mod is to remove ONE return spring from the centrifugal advance unit.
The RESULT is that it allows faster Ign Advance & at lower RPM.
The EFFECT is that it reduces Honda's tendency to "bog" /Die when Throttle is snapped open too fast at LOW rpms from sudden vaccum drop.

The remaining advance return spring ,,plus the Drag of the Point's rubbing block on the point-cam is more than sufficient to fully retard the ign for correct starting and lowspeed operation.
In other words,,"It cannot hurt anything by removing the one spring"

Actual Ignition Timing "should be" set advanced a SMALL amount---approx the width of " 3 timing marks ".
Meaning,,,rather than having marks exactly aligned on rotor,,,
Offset them about THIS actual amount>> iii.
About an 1/8" offset ADVANCED>>>rotor mark Clockwise of Mark on engine.
That SMALL amount is NOT for the mere purpose of Advancing the Timing,,but to COMPENSATE for Wear on engine/ignition parts.
After Timing is Set ---it's always on a downhill slide---wearing Out of Adjustment.
When set Spot-On----it wears AWAY from "Correct".
When set a BIT ahead---it wears INTO "correct".

Answer 2

Always give year, make, engine size and model # when asking questions. We need "all" of that info to give an informed answer.
Those bikes never had a govenor.
There's no way a z50 should out accelerate an xr100.
Depending on the year, the points & timing may need adjusting.
***Check that first using a timing light.
Depending on the year of the bike, it could be ready for a rebuild.
Valve job, valve adjustment, piston & rings, cylinder bore.
One item you can check real quick - make sure the air filter is clean (I don't think that will have anything to do with your problem).

Answer 3

Sounds like you got a good mess on your hands. Here's the deal, If the bike has points you may be able to adjust them through the slots in the flywheel and be on your way. However, if you end up having to pull the flywheel there are a few things you can try. You said the puller lost its threads, so, you could invest in a new puller and try again, this time use some pentrating oil and some carefully applied heat. Worst case scenario, flywheel threads are stripped, then screw the puller in best as can be, tack weld the puller to the flywheel and pull it off. You could then add a new flywheel to your list of needed parts, sorry, not many options in this case.

Answer 4

Xr100 Honda

Answer 5

Don E had a good answer,you also need to look for a restrictor in the exhaust. Pull off the pipe from the head and look for a what looks like a washer, it could be in the head or the exhaust and take it out. Look at the throttle on the handlebars, if it has a screw in it that sticks out...take it out-it is a limiter- You can also check the baffle,it may be restricted. look for a set screw in the end of the exhaust pipe,unscrew it and take the baffle out. On the end of the baffle it might have a flat round piece with holes in it. Pop off the flat piece (vice grips work great) and it should dramatically help the bike.

Answer 6

Xr100 Specs

Answer 7

If it's a governor, then when you get to a certain speed, the gas will simply cut out for a moment. My car for example, if I get to 110, the gas cuts off momentarily. But I can accelerate just fine up until that point. So if his cuts out at a certain speed, it's a governor. Otherwise, there's something else wrong.

Answer 8

Remove the top of the carb.and pull the slide out.Now, when you turn the throttle,does the carb. slide go to the top of the housing?Check handle bar throttle,should only have about 1/8th inch free play before carb. slide begins to move.Make sure throttle grip is not pressed against end of handle bar.Check timeing.

Answer 9

don e has the best answer. In my opinion your bike doesn't have a governer on it

the answer with the chick that blew someone that's a mechanic is hilarious.

Answer 10

sounds like a blocked air filter, just get a replacement (although don't run the engine without a filter!)