NC30 dyno 45hp :(

[krisztian_andre]

Hey, thank you! But that was funny.
Just talked to Rick about it and he says the screws are on the inside of the carbs and the hole on the outside is just a blind. I will recheck it tomorrow.

[Neosophist]

So far
- needles where the wrong way around
- emulsion tubes mixed up
- rubber flap missing
- pilot screw assemblies 16016-ML0-721 completely missing !!!

If anyone has pilot screw sets and a rubber flap for sale, let me know.

I don't think your biek will run without pilot screws. There on the inside of the carbs.

Screw them in VERY gently, dont' force them.. put a dot mark on the handle of the screwdrvier to make it easy to count and count every full turn (cmopletel revolution) of the pilot screws until they are fully screwed in.

Back them all out to the right setting.

PS: if everything seems backwards.. you dont' have the carbs the wrong way do you?

[krisztian_andre]

Yeah, I've rechecked, pilot screws are there actually. I was wondering, if there's oil in the intakes on the head, that means worn valve stem seals. Can you replace those with the engine in the frame and the heads on?

[CMSMJ1]

Oil where?

You cannot remove the valves with the heads on..

Valve stem seals would give you some smoky exhausts

[krisztian_andre]

In the intake port. I don't want to remove the valves, just the stem seals. There's some whitish smoke at high rpm at throttle cutback.

[CMSMJ1]

you have to remove the valves to get the stem seals - as far as I can figure out.. You need to remove the valve springs to get to the seals.

To remove the springs, you need to have the head off.

I'd reckon that a tiny bit of oil in the heads is due to it not running properly

[krisztian_andre]

I got the a/f graph and it looks like a mountain range.

I'm still trying sort this out and since then the carbs have been sorted an I think it's safe to say that that isn't the problem. I'm wondering what causes the rich condition with a standard setup and I don't think it is the climate since other vfrs around here have no such problems.
A new possibility could be a plugged exhaust (I have an old standard system) but that wouldn't explain why the curve is so rough. I'm starting to suspect an ignition problem since the bike starts running like crap when it's hot, maybe the coils or the CDU have a defect that gets worse with temperature.

Why is the A/F ratio decreasing at the end of the rev range, can it be that the increasing vacuum in the intake sucks in oil by the valve seals and that's richening the mixture or the faulty coils can't supply enaugh voltage as the time between sparks decreases?

Am I making sense?

[pip]

A plugged exhaust???
That is too rich plain & simple, what mains have you got - assuming the air filter is good, try smaller mains for starters.

[krisztian_andre]

A plugged exhaust???
That is too rich plain & simple, what mains have you got - assuming the air filter is good, try smaller mains for starters.

The bike is as standard as it gets, air filter is new. I can see it's too rich, the question is why is it rich, why are the power and A/F curves so rough adn why does the A/F ratio decrease at the end?

[bikemonkey]

I see you mentioned you don't have the rubber flap, maybe that's causing turbulent air in the airbox not allowing enough to flow through properly?/hot air from the rad getting into the airbox?