When kicking over my 1970 Norton, it is really hard to do. It has new piston rings so I know compression is strong. The strange thing is that when I raise the Mikuni (choke) lever it is much easier to kick. Lowered to normal and opening throttle, it gets almost impossible to kick. Another question is ...should the kick lever go all the way through giving an almost double compression or not? Much of the time the kicker goes halfway and stops hard. I haven't learned yet how to tell when pistons are at tdc yet. Hope you can figure out what I am asking!!
Kickstart question
- Thread starter kempoyner
- Start date
- Status
Fast Eddie
VIP MEMBER
- Joined
- Oct 4, 2013
- Messages
- 22,261
kempoyner said:
Hello,
Look on the bright side... at least it seems you have strong compression!
As to whether anything is wrong, like the kick start jamming, or whether it is simply 'stopping hard' because you have nice strong compression, is really difficult to tell from your description. And is probably not actually possible to resolve via forum messages to be honest.
I can tell you this though, operating the choke lever on a Mikuni cannot possibly effect how easy it is to turn the engine over. If you think that, it must be coincidence. Something else is happening at the same time, that actually IS effecting things.
Your best bet would be to find someone local to take a look.
As the advice above says, it is an acquired art - my suggestion would be to kick it over slowly until you feel the full compression - then stop and let the lever return to the uppermost position. Then, when you're ready, you sort of bounce up with your left leg and put your full weight on the kicker and give it all you've got. If you get it right, you'll hear a loud noise from the ends of the exhausts! 
- Joined
- Feb 10, 2009
- Messages
- 3,079
Easier to kick over with throttle shut.
- Joined
- Nov 20, 2004
- Messages
- 20,784
kempoyner said:
When the choke plunger is raised it opens an air passageway that bypasses the throttle slide.
http://www.mikuni.com/pdf/vmmanual.pdf
- Joined
- Feb 10, 2009
- Messages
- 3,079
More air getting in will make it harder to kick over compression.
L.A.B. said:
I believe LAB is trying to suggest that if the engine cannot pull enough air in as the piston falls it can stop or significantly slow the piston. To test kick till the engine locks then while keeping your weight on the lever open the throttle. If the piston moves then increase tick over screw setting to raise the slide. Once engine is running and warmed up further adjustments of idle speed and air screw can be made.
Kicking engine over slowly with no plugs in would be first thing I would do to though to check it is free and all is moving as it should.
- Joined
- Dec 28, 2009
- Messages
- 5,498
Pull the plugs yes , and the 3 valve covers to observe rocker liftings and droppings. You should be able to do it crouching down and moving kicker with left hand. Or ask for help with that whilst you observe valves.
- Joined
- Feb 10, 2009
- Messages
- 3,079
I find that a closed throttle makes the intake stroke slightly stiffer, but not enough to matter and makes the subsequent compression stroke much easier.
But if other people find it all different, they should share their experience too. It's their leg and their lever.
But if other people find it all different, they should share their experience too. It's their leg and their lever.
- Joined
- Apr 7, 2010
- Messages
- 45
There are numerous threads here on kick starting and one mentions catching-rolling on the throttle just as the bike fires. My technique on 850 with Mikuni and trispark is to kick thru compression with ignition off, turn key on, use enrichener unless over 80 degrees, kick thru with throttle closed and give it gas when fires. Immediately shut off enrichener. Normally starts 1st kick. Before I replaced my Boyer I experienced same as you with kickstarter stopping suddenly, felt like something locking up mechanically, has not done it in 3 years with trispark. Also remember opening throttle with Mikuni defeats the enrichener.
DogT
VIP MEMBER
- Joined
- Jan 20, 2009
- Messages
- 7,393
I actually have to get myself up with both feet on the pegs, push the pistons just through compression, return the kick start lever to the top and then give it both barrels. I just can't push it over from the side or without my weight helping. For sure my methodology is to get the engine through the second compression stroke in the initial push which means the lever is down near the bottom at that point. Once in a great while it will start going through the first compression, but not when it's cold. 750 and Pazon with original Amal carbs and 20W50 V-Twin oil. I don't notice any difference choke on or off. It's certainly easier when it's warmed up.
Others don't seem to have my problem. I've seen people start my bike sitting on the seat and just pushing it through with their right leg.
Others don't seem to have my problem. I've seen people start my bike sitting on the seat and just pushing it through with their right leg.
I have owned my 1970 Roadster for 42 years. It is actually quite easy to start. Probably the simplest is to push through a compression stroke until you feel the resistance taper right away. Don't kick (push) through any more but reset your kick start lever to get a full swing at it. Once you get a bit of flywheel momentum, it should fire right up providing all conditions are favourable, eg. gas in the tank and turned on, a brand new Mikuni 32 mm single carb. This carb totally eliminated all the starting, running and syncronizing issues, choke cables and best of all . . . . smelly gasoline fingers !! I still have the Amals but considered donating them to a museum. Good plugs and good electrical connections (high tension leads) points correctly set and not pitted. Good compression. My machine fresh from a $1600 engine rebuild top to bottom got 150 psi in both sides. Yes it does take a bit of practice but in the end, it's worth it.
- Status
