Total NOOB needes help starting bike!

Hello, everyone! I picked up a '78 KZ650 yesterday and I have never ridden a motorcycle before. I have somebody to teach me how to get started riding it but i need help starting it. it ran fine when i got it and is in good shape, i just dont know how to start it! I scheduled a motorcycle safety course in May but i need to get aquainted with my bike first.

A few questions:

Where do i need to position the choke to start it cold?

And the petcock is a manual device, it has three positions, where do i need to position it to start the bike?

I flooded the heck out of it this morning. I removed the plugs and they were wet and covered in black. i cleaned them, and they have been out of the engine for hours. The guy i bought it from said not to give it any throttle at all when starting it cold because it floods easily. Guess i twisted it a bit.

i will post pics when i get home!

i am a motorcycle virgin and am excited to pop my first cherry! haha. cheers everyone!

-David

Great choice for a first bike!!! Just make sure you respect the throttle, these 650s are deceptively quick and could get away from you in a hurry if you're not gentle.

As far as starting goes, pull the choke all the way open (lever to the upward position). The bike will start easiest in this position, might not have to stay there long though, keep your eye on the revs and listen to the bike, it'll tell ya when it's ready to lose some choke. Don't cut the choke all the way from full on to full off either, lower about half way initially and let it run there for a bit before dropping it off completely.

Petcock, if manual, will have three positions, ON, OFF, and RES. You'll want it on ON most of the time, RES (reserve) when your tank is getting low and starts cutting out on ON. ALWAYS TURN THE FUEL OFF when you park the bike.

If the petcock is vacuum style (which I think they were in 78) it'll have three positions, ON, RES, and PRI. ON and RES are the same as the manual, PRI is prime. Use this to allow fuel to flow freely into the carbs after a long set (more than a few days of not riding/starting). With the vacuum petcocks there is no OFF position as the diaphragm in the petcock only allows fuel to flow based on engine vacuum or when turned to the PRI position.

Hope that helps!

Thanks! You answered many of my questions. I will try giving it a start later today. I hope i didnt leave the petcock in the on position when i left the bike. i assume it will fill the carbs with fuel right? i havent put the plugs back in, how would i know if they are ready to go back in the engine? i am hoping to fill my garage with a little exhaust and hear my baby purr! thanks!
-david

Hello Davestradamus and WELCOME to KZR!
We're glad you're here!

In the green ribbon toward top of screen, pointing to "KZ Information" gets the dropdown menu, then click on "Filebase." Then click on "1978." And several KZ650 links appear. Lots of interesting info available. Such as specifications, wiring diagram, owners manual, etc.

Let us know if any problems accessing the links.

Good Luck!

Dave. welcome.. While many bikes have slightly different wants for starting, most common for our pets is, neutral,full choke (when cold) no throttle.. many kz650's prefer to be kicked, especially if not ridden frequently. have fun G

Davestradamus wrote:

Thanks! You answered many of my questions. I will try giving it a start later today. I hope i didnt leave the petcock in the on position when i left the bike. i assume it will fill the carbs with fuel right? i havent put the plugs back in, how would i know if they are ready to go back in the engine? i am hoping to fill my garage with a little exhaust and hear my baby purr! thanks!
-david

If your float needles and seats aren't in tip top shape and you leave the gas ON you might come out to find a little puddle of gas under your bike. If the carbs overflow they have drains on the bottoms of the float bowls that will allow the excess fuel to flow out. If the plugs are dry they can go back in, after a couple hours the excess gas in the cylinders should have evaporated as well. And yeah, these old girls don't like you to twist the throttle until they're purring already. Full choke, gas ON, no throttle and she should fire up pretty easy if she's running good.

Welcome, Dave!

The other guys have covered it well. So I don't have much to add except the clutch lever needs to be pulled in to use the electric starter and left engaged to use the kicker.

If an in-line fuel filter isn't already fitted, please install one asap.

Over-rich idle might be caused from too high fuel level in float bowls, or possibly blocked air passage in carb pilot circuit.

Here's the simplest possible remedy ---
Am thinking the carbs are manual slide (not cv vacuum operated) and which have side located pilot air adjustment screws. Am guessing the default position of pilot screws is 1.5 turns out from lightly seated. So would start from that default position. If excessive richness at low idle continues, turn the pilot air screws out another 1/4 turn (allows more air into the pilot mixture) and try again. Repeat if necessary. But if adjusting the pilot air screws has no effect on the engine rpm, there's likely something wrong inside the carb.

Would also assure the air filter is clean, clear and unobstructed (with a shop rag or something). Could just remove air filter while testing.


One more thing - - - would sniff-test oil and examine oil to assure no fuel contamination inside crankcase. This can happen when the petcock allows fuel flow to a leaking float needle/seat interface and excess fuel passing into floatbowl can't escape due to a clogged overflow circuit.

Good Luck!

THANKS EVERYONE!

your replies have been very helpful. i downloaded the wiring diagram and the repair manual online. and the resources on this site are going to help me lots in the future. one problem: i still cant start my bike!

when delivered on wednesday, the bike started easily with the electric starter. but not anymore. i was told the petcock is no longer controlled by vacuum and the "res" position is off, the "pri" position is on and the "on" position was off.

with the choke handle all the way up and the petcock on prime no throttle: with the electric starter it sputtered lightly then died. and no more sputtering after.. i think i flooded it, the plugs smelled like gas. there was a cap on the one of the drains for the carb. i took it off and it was pretty wet. i think i need to dry it all out and start over?

thanks,
david

Spark plugs may be hopelessly fuel-fouled.

Would install four brand new plugs, and try again.

Assure correct plugs. Am thinking NGKB7ES (but might be NGKB8ES).

Good Luck!

Davestradamus wrote:

... was told the petcock is no longer controlled by vacuum and the "res" position is off, the "pri" position is on and the "on" position was off... there was a cap on the one of the drains for the carb. i took it off and it was pretty wet....

Am suspicious about the petcock and whether it's actually functioning to disallow fuel flow in either ON or RES position without vacuum.

There are nipples exiting from bottoms of floatbowls where excess fuel escapes. These nipples should not be capped off, but should have tubes connected to them routed to underneath the bike. If improperly capped, excess fuel from the floatbowl goes into the crankcase instead of out underneath the bike.

Remember to sniff-test the crankcase oil.

Good Luck!