KICK STARTERS


Kickstarter




To me, kick starters fall into two groups. Those you can fix easily and those you can't easily fix. Let's look at the hard to fix ones first.

Internal Kickstart GearsInternal Kickstart GearsSome designers place every part of the kickstarter inside the crankcase, with only the shaft sticking out. The kickstarter has a gear on it's shaft. That gear moves back and forth on the shaft in grooves cut in the shaft. When you turn the kickstarter the gear is thrown into mesh with an idler gear which in turn is in mesh with the mainshaft of the transmission. The mainshaft is connected to the clutch and the clutch is connected to the engine crankshaft. When the engine starts and you release the pressure on the kickstarter, the kickstart gear is thrown out of mesh with the idler gear. The problem with this arrangement is that all the kickstarter gears and springs are within the crankcase. You must remove the engine from the frame and split the crankcase if a gear or spring breaks. This is not good. A lot of the early Honda dirt bikes were like this.

A slightly better way has the kicksarter return spring on the outside of the crankcase and everything else on the inside. At least with this arrangement you can replace the spring if it breaks.

External Kickstarter GearsExternal Kickstarter GearThe best way is with everything on the outside of the crankcase. It basically works the same as the internal type but you can easily get to everything to fix it. Just take off the clutch cover and, at worst, the clutch basket and there you are ! The kick starter shaft turns, forcing the kickstarter gear into mesh with the idler gear. The idler gear is already in mesh with the big ring gear on the clutch, which is also in mesh with the gear on the end of the crankshaft. All this turns the engine over and starts it up !

Starter Gear and ClipTo work, the starter gear has to be able to lock in place when the kickstarter is depressed and then unlock when the kickstarter is released. There are a lot of ways to do this.

In a Lateral Engagement kickstarter, grooves on the shaft allow the gear to move back and forth, engaging the idler gear to start the engine and then disengaging the idler gear when the engine starts. This is done with a friction spring clip around the shaft and grooves cut at an angle on the kickstarter shaft. When the shaft is turned in one direction, the gear moves lengthwise along the shaft. When the shaft turns the opposite direction, the gear also reverses direction. The friction spring clip rides in a groove cast into the

A Full Ratchet kickstarter is another way to engage and disengage a starter gear. A beveled edged arm, or Ratchet Tab, is cast as part of the starter ratchet. This arm pushes against an angled metal lock out plate, when the kickstarter is at rest, pushing the ratchet out of mesh with the starter gear. The starter gear is in mesh with the idler gear and spins with it freely. Pushed by a spring, when the kickstarter shaft is turned, the ratchet locks with the starter gear turning the engine over, and starting the engine.

In a Pawl Ratchet kickstarter there are pawls between the kickstarter shaft and the kickstarter gear. These pawls lock the shaft to the gear when the shaft is turned one way and release the shaft when it is turned in the opposite direction.

Lastly is a Quadrant Gear kickstarter. It uses a kind of half gear that engages a kickstarter pinion gear when the kickstarter is rotated. This spring loaded pinion gear has ratchet teeth that allow it to lock up when turned in one direction and slip when turned in the opposite direction.

Most all kickstarters use one of these four methods of engaging the kickstarter gear. However, the details may vary a bit between manufacturers and even between different engines from the same manufacturer. Check your shop manual !

Exhaust LifterPunch MarksSome dirt bikes have an automatic compression release. This is a little cam on the kickstarter shaft that pulls on a cable, activating the compression release at just the right time, allowing you to start the engine with less effort. When you install the cam onto the kickstarter shaft there will be tiny alignment punch marks on the kickstarter shaft and the cam. These punch marks must align so the compression release works at the right time. Speaking of punch marks. Some starter gears must be aligned to a certain position on the kickstarter shaft. Punch marks are used here too. Always look for punch marks, on the shaft and gear, as you take the kickstarter apart and match them up when you reassemble things.

This gives you an idea as to how the kickstarter works. The exact way is detailed in your shop manual but the general principles are all the same. The kickstarter shaft must lock up when you kick it and unlock when you release it. I've seen some manufacturers of dirt bikes have five or six different variations of basically the same kickstarter on their bikes. Why the changes, and they are all very minor changes, I cannot say. Got to be new and improved, right ?

Some dirt bikes can be kickstarted with the clutch in and some can't. If the kickstarter gears bypass the clutch, then it can be started with the clutch disengaged. If the power of the kickstarter goes through the clutch then you will have to put the bike in neutral and the clutch engaged, to kickstart the engine. It just depends on the design.

The kickstarter must be able to spin the engine at least three or four hundred RPM. Most electronic ignition systems have an anti kick back feature that cut the ignition at low speeds.

Just about all the newer street bikes have no kick starter at all. I guess they think we are all wimps and can't kickstart our bikes in an emergency. Maybe they are right. All the movies I see now, have the big, bad, biker gang types, who run out, jump on their bikes and hit the button. It just isn't the same as when they kickstarted them !

For lots of exploded views to study click Here !



Back to M/C Repair Course

Did this page help you ? Would you like to help us ? If so Click HERE

BACK TO INDEX

MOTORCYCLE HOME PAGE

Copyright 1999-2005 dansmc.com. All rights reserved.