Hard to Cold Start (2011)

Camshaft timing..ok, makes sense- I will check it out.

As for the killswitch, it does not have one, the right hand switches don't even have wires coming out of them. will study the wiring diagram and see where if at all, it interacts with the system and if it is still in there.

The needle position is in the middle position of 5 I think- will try that first because it is the easiest and give it another road test :wink:

Rod in the femur- caught in the middle of a nasty crash on the motorway, got squashed between a 6 car pileup. Very nasty.

Right. I will give those things a try. Thank you, and if anyone else has some suggestions I am open to anything as my efforts have so far been exhausting and exhaustive and so far in vain

There are ten rollers between the two marks on the camshaft and crankshaft wheels as per the manual. Is there any way the wheels can be fitted to the crankshaft and camshaft or is there only one way they will go on. In other words is there any way this could look right but be wrong? I did get to check the ignition wires inside the case now the cover is off and they were fine.

I have a bit of time up my sleeve because the oil seal for the points chest has been damaged when the timing cover was originally fitted and a part of the sealing lip is bent back on it's self so I will need to get another one. There was a tiny bit of oil in the points cavity so it has been marginally leaking. Will fix that while it is off :roll:

Had a look at the wiring diagram and there is no kill switch fitted to my bike. I will run a wire direct to the trispark ignition when I get it back together again, I can always stall stop it after a trial ride


Phew, I am really dedicated to getting this darn bike running properly. It has to be something wrong somewhere...

Hello Evereybody.
I'd like to reopen this thread by the huge issues of cold starting my bike.
Similar to the opener I need 10 - 20 kicks before the bike fire up.
Runs good, good idle once is warm, good start once is warm. No pops in accelaration, good stady idle ( 800 rpm)
Set-up:
Tri Spark Ignition, Standard Coils 2x6V, Batterie is fine ( 12.6V at Start, battrie is stable under load at 12.3 V)
Mikuni VN34 and I use the org. air filter 8reworked by 1 hole) Slide 3, Needle 6DH3 Main 250, Air jet 2.0, Idle jet 35 (even 30, 32,5 no influence), Needle jet 159-P5. Air Screw is 1 1/4 turn out.
Plugs are: Chmapion, NGK, Irinium cehecked, nothing is better or worse!
Plugs are dark brown, a bit to rich, but runs good.
Motor was build up by new pistons, and new valves at a overhauled Head.
Rest is org.
Setup of Tri-Spark was checked twice by static adjustemnt of LED indicator.
The plugs are NOT wet once I check them after 4-5 kicks.
Procedure:
checked by 2-3 kicks without ignition and with chocke and then with ignition, or try to start directly, all without succeding.
Do I overlooked something?
Should I increase the idle jet? Now 35
I mean, for me it seems there is NO extra gas for cold start. But How can I check that?
This all stress my leg extremly and I'm really close to sell the bike and buy a BMW
No...NO.... NEVER!
Not acceptable for me to resign at all.

Regards Lorenz

Mikuni idle circuit (s) PARTIALLY plugged.
Assume you are using throttle CLOSED while cranking.
The bike has been with you a while? Or new to you?

Lorenz said:

Mikuni VN34

Click to expand...

Assume you mean VM34.

Lorenz said:

Runs good, good idle once is warm, good start once is warm. No pops in accelaration, good stady idle ( 800 rpm)

Should I increase the idle jet? Now 35

Click to expand...

If it idles/runs well when warm as you say, then probably not.

Lorenz said:

I mean, for me it seems there is NO extra gas for cold start.

Click to expand...

That is unusual. The VM cold starting mixture is usually rather too rich. Dry plugs suggests the cold start jet (or part of the cold start system) could be blocked. This is a fixed jet in the float bowl.

Amal Tickle/flooding system:
Raised fuel level enrichens the fuel air ratio for initial fire up.
Upon running the fuel is consumed and by further functioning is automatically leaning out as the fuel level drops.
This removes the operator from assessing the running fuel ratio and creates an almost hands off operation.

Mikuni Enrichener system:
Lifting the lever opens the starter enrichener circuit.
This circuit is tuned to fire up with the throttle closed.
Normally it is very rich and unfortunately will continue very rich and only cease upon control by the operator.
This over rich running has a fruuuumpfruuuumpfruuump sound often called 8 stroking.
After the enrichener is off:
I have heard many mic carbs running and they vary significantly from very lean to very rich.
Even with the enrichener off, on the rich ones, I have often noted the partial throttle sound of mild 8 stroking.

concours said:

Mikuni idle circuit (s) PARTIALLY plugged.
Assume you are using throttle CLOSED while cranking.
The bike has been with you a while? Or new to you?

Click to expand...

I used throttle closed and open! I tried EVERYTHING!
My norton been with me since 2 years. The issue of bad cold start comes after rebuild the motor.
When I bought the bike the VM34 was with 290 main and velocity stack. Due to wear out piston kick start was much easier! I've throw away the stack and build in a standard air filter. Looks better for me!

L.A.B. said:

Assume you mean VM34.



If it idles/runs well when warm as you say, then probably not.

That is unusual. The VM cold starting mixture is usually rather too rich. Dry plugs suggests the cold start jet (or part of the cold start system) could be blocked. This is a fixed jet in the float bowl.

Click to expand...

YES VM34
Sorry.
Yes runs smooth when warm, so i will not touch the idle jet .
I will open the Mikuni tonight and check the Starter jet in the float bowl.
Thank you all for the kind reply.
Lorenz

Before cold starting, pull the plugs and squirt a little gasoline ( 5 CCS +-)
down the holes.
Put the plugs back in quickly and try to kick start.
If it starts or tries to start on the first or second kick then you know the issue is fuel related.

Glen

worntorn said:

Before cold starting, pull the plugs and squirt a little gasoline ( 5 CCS +-)
down the holes.
Put the plugs back in quickly and try to kick start.
If it starts or tries to start on the first or second kick then you know the issue is fuel related.

Glen

Click to expand...

Hi Glen.
Good idea. I will follow. Carb is not disassembled yet.
5 CCS mean 5mL ? That is a bit high amount, isn't it? Or what does mean 5CCS? Google doesn't help me in this case.

Lorenz said:

Hi Glen.
Good idea. I will follow. Carb is not disassembled yet.
5 CCS mean 5mL ? That is a bit high amount, isn't it? Or what does mean 5CCS? Google doesn't help me in this case.

Click to expand...

Just a little amount
No more than a tea spoon full

baz said:

Just a little amount
No more than a tea spoon full

Click to expand...

OK, then it seem to be 5 ml = 1 tea spoon.
Will use an injection.
Thanks for the help.

I've never put gasoline directly into a cylinder so I have no personal experience with the method but a teaspoon sounds like an awful lot of gas to put directly into the cylinder...

I would use a shot of starting fluid or a spritz of gasoline into the carb - same effect as tickling Amals!

Lorenz said:

Hi Glen.
Good idea. I will follow. Carb is not disassembled yet.
5 CCS mean 5mL ? That is a bit high amount, isn't it? Or what does mean 5CCS? Google doesn't help me in this case.

Click to expand...

Hi Lorenz,
So there be no confusion, 1 CC (cubic centimeter) is equal to 1 ml (milliliter).

Ed

I've done this with umpteen hard to start motors for 50 years without issues.
It clears up the question " is it fuel, or is it spark" in a couple of minutes.
Yes 5 CCs is 5 ml. That's an approximate amount to divide in half, half in each cylinder.

Glen

Lorenz, I use a simpler method to test for fuel starvation. I use a squirt bottle filled with fuel like the one pictured below.




I remove the air filter, lift the carb's throttle body and give a squirt into the mouth of the carb. If the bike starts with the squirt of fuel, then it's a fuel delivery issue. If it doesn't try to start, it's usually ignition/timing/electrical. It's simpler than pulling both plugs and putting them back in...

You can pull the plugs and replace in a couple of minutes, it's about the simplest thing on a bike.
Getting the air cleaner or carb boots off and on isnt alwaysthat easy, in fact it's a real pain on mk2a and MK3, worse yet on my 650ss. I need about half an hour for that one! Not sure what Lorenz is working with.
I like to get the fuel right into the combustion chambre, same idea as a wiring bypass.
If it doesn't show life right away, start looking at ignition.

Glen

Starting fluid sprayed on the air cleaner will do it too. Don't over do it.