First Start Since 2008

[tom203]

Any have ideas as to why the revving is happening? What I know is detailed in my last post.

Make sure throttle cable has some slack.
Did you bench sync these carbs, so throttle plates are all about same ? They will appear almost fully closed across carb throats when sitting on idle stop screw.

[TheYukbob]

Make sure throttle cable has some slack.
Did you bench sync these carbs, so throttle plates are all about same ? They will appear almost fully closed across carb throats when sitting on idle stop screw.

Ok, I checked the things you said, the throttle cable has slack and yes I did bench sync them. They are almost fully closed at idle so the idle screw is not set too high. What else can I look for?

[TheYukbob]

1st off... Hi Fellow NTX member!

Is it blowing any black smoke when its revving? And I know it sounds silly, but are you sure you just don't have the idle speed adjusted up too high? Also, sometimes if the throttle cable isn't routed correctly they can rev when the bars are turned.

No, there's no black smoke but it is running very rich as I can smell gas from the exhaust, also the bars are completely straight. My mixture screws are at 3.5 turns out, is that what's causing this?

[TxGSrider]

No, there's no black smoke but it is running very rich as I can smell gas from the exhaust, also the bars are completely straight. My mixture screws are at 3.5 turns out, is that what's causing this?

I don't have any experience with your model, but most carbs are between 1 and 3 turns out, and that could cause the "richness" however it wouldn't explain the high idle. Try turning the idle speed screw out some... maybe you just have it set too high.

[TheYukbob]

I don't have any experience with your model, but most carbs are between 1 and 3 turns out, and that could cause the "richness" however it wouldn't explain the high idle. Try turning the idle speed screw out some... maybe you just have it set too high.

Alright I tried between 2.5 and 3.5 turns out and now it won't even start. Though that may be because it's 45°F outside where I am?

[TxGSrider]

Alright I tried between 2.5 and 3.5 turns out and now it won't even start. Though that may be because it's 45°F outside where I am?

It was 57 this morning... ya shoulda started working on it sooner- lol .... that cold front cooled things off today, didn't it?

Will it start with the choke on? And are you adjusting the idle speed or idle mixture screws?

[TheYukbob]

Oh yeah it cooled down fast, I was watching co-workers reactions as they walked out the door!

And no, it won't start with choke on or off.

The idle speed is set pretty low and the idle mixture screws are currently 2.5 turns out on each carb. I'll try to start it with a higher idle speed than what I previously had tomorrow afternoon as my workshop is next to my neighbors bedroom.

EDIT: Tomorrow isn't getting above 50°F either so maybe I'll wait...

[TxGSrider]

Mine will start within a few seconds even at freezing... but that's usually all I will do with it when its that cold out. lol

[TheYukbob]

Thanks for your help, I'll post back here when I try and start it again when it's warmer out.

[TxGSrider]

Usually valve lash being too tight will make them hard to start when the engine is cool... and dang near impossible to start when the motor is real cold (like right now). I kinda skimmed through your posts but I didn't see if you had adjusted them or not.
I'm just throwing out some ideas... but it kinda sounds like you may have a vacuum leak somewhere. It may explain why you have the idle screws out that far and the fast idle even with the idle speed turned way down.

[BigD_83]

The only things that I can think of from the top of my head that will cause that sort of revving at startup are a massive air leak, the idle set too high, a bound up cable, or a stuck throttle rod. The binding cable is a weird one, as it can appear to have slack at the throttle tube, but bind below the mounting bracket. Sometimes when pulling the carbs, that bracket gets bent; a relatively minor change in angle can have a pretty big impact.

I couldn't see in the video, but do you have the airbox installed?

[TheYukbob]

Usually valve lash being too tight will make them hard to start when the engine is cool... and dang near impossible to start when the motor is real cold (like right now). I kinda skimmed through your posts but I didn't see if you had adjusted them or not.
I'm just throwing out some ideas... but it kinda sounds like you may have a vacuum leak somewhere. It may explain why you have the idle screws out that far and the fast idle even with the idle speed turned way down.

I'm about to replace the camshaft cover gasket due to it leaking and thought about checking the valve lash then, but the bike only has 2130 miles on it, should I still check them?

[TheYukbob]

The only things that I can think of from the top of my head that will cause that sort of revving at startup are a massive air leak, the idle set too high, a bound up cable, or a stuck throttle rod. The binding cable is a weird one, as it can appear to have slack at the throttle tube, but bind below the mounting bracket. Sometimes when pulling the carbs, that bracket gets bent; a relatively minor change in angle can have a pretty big impact.

I couldn't see in the video, but do you have the airbox installed?

Where I was checking for slack in the throttle cable was at the carbs, not the throttle tube, but thanks for that suggestion. I know an air leak is the most common issue but the intake boots and orings and are brand new.

And yes, I do have the airbox installed with a filter, but it's not oiled. Is oiling it really that important?

[TheYukbob]

Alright I made some decisions on what to do now that the bike won't even start anymore, first check the valves when the new gasket comes in, second I'll wait till it gets warmer outside because I checked the block temperature with an infrared temp gun and it reads 35-36°F all over the engine.

[TxGSrider]

Alright I made some decisions on what to do now that the bike won't even start anymore, first check the valves when the new gasket comes in, second I'll wait till it gets warmer outside because I checked the block temperature with an infrared temp gun and it reads 35-36°F all over the engine.

That is probably a good idea sir.