New boots! Still won't idle.

[UncleMike]

If your float adjustment is off, yes. But I'm just throwing out suggestions because as many times I've had my carbs on and off I feel I should be a pro. When your bike stalls pull your plugs and see if it's rich or lean.

Okay, here's the first stupid question of the night,...

The bike has stalled many times since putting new plugs in. Does starting it again after it has stalled ruin the reading I'd get on the plugs? How does that work?

Thank you, thank you, thank you for trying! I'm trying to get to Moosehead!

 

[Guest]

Clean the plugs and try it. For example a throttle chop, you cut the engine at the troubled circuit and cruise to the side of the road with clutch in so you get the reading at that exact moment. So if you try to start it and run it you won't get the correct reading.

 

[KEITH KRAUSE]

Getting late and I didn't read all the other replies.
Some quick thoughts...
Does it still have the problem if you turn the petcock lever to PRIME?
If using the gas tank, does removing the gas cap help? If using a fuel reservoir, is it vented adequately?
Is the throttle cable adjusted EXACTLY per factory recommendation?
If you deliberately turn up the idle speed an additional 200 rpm's (just for testing purposes), will it now hold an idle?

 

[UncleMike]

Clean the plugs and try it. For example a throttle chop, you cut the engine at the troubled circuit and cruise to the side of the road with clutch in so you get the reading at that exact moment. So if you try to start it and run it you won't get the correct reading.

What does "at the troubled circut" mean?

 

[UncleMike]

Getting late and I didn't read all the other replies.
Some quick thoughts...
Does it still have the problem if you turn the petcock lever to PRIME?
If using the gas tank, does removing the gas cap help? If using a fuel reservoir, is it vented adequately?
Is the throttle cable adjusted EXACTLY per factory recommendation?
If you deliberately turn up the idle speed an additional 200 rpm's (just for testing purposes), will it now hold an idle?

Prime and gas cap have no effect.

I'll let you know about the throttle cable, but yes, turning up the idle speed will allow it to idle, albeit at 1500 or higher.

 

[retchidxs]

is there any chance your sparkplug wires are bad? my brothers ford wouldnt idle and he had the shop look at it and they fixed the plugwires and did a idle adjust. i read you did the idle so could you have a weak spark you think and when the motor heats up and revs up it gets stronger? crazy idea? i'm just guessing.

 

[UncleMike]

is there any chance your sparkplug wires are bad? my brothers ford wouldnt idle and he had the shop look at it and they fixed the plugwires and did a idle adjust. i read you did the idle so could you have a weak spark you think and when the motor heats up and revs up it gets stronger? crazy idea? i'm just guessing.

Nice blue spark on all four plugs.

 

[Jethro]

Boy has been working on it since 7:22 this morning!! You are on the path, I know it!!!

Yes, float heights can make or break how a bike idles. I use a clear tube attached to the float bowl drains to confirm the float heights, and make sure they are perfect. Remember that idleing (the pilot jet in general) is the most complex function a carb performs.

Really sounds like fuel starvation of some sort to me. Even with dirty carbs with weak spark, if it idles for ANY amount of time (even a few seconds) you should be able to get it to idle- if it is getting fuel. Fuel is the only thing that could change so fast, due to the float needles, or flow to the carbs, float needle seat filter, float bowl vents, fuel line...

You are probably sick of questions that you have already been over, but lets start at the beginning anyway...

1. Gas cap vent is ok as you said
2. Petcock flows nicely
3. Fuel line is 5/16" ID? As you asid not kinked.
4. Vaccum line is free and attached
5. Float bowl gaskets are sealing well? This is an often overlooked air leak.
6. Float heights are correct?
7. The little port at the side of the float bowl for the starter jet is free?
8. The starter jet tube is clean and clear?
9. Float needle seats were cleaned? Filters are clear?
10. Pilot jet was removed and is clear?
11. Emulsion tube was removed and cleaned?
12. All jets and needles are stock sizes?
13. Mixture screws are cleaned and in good shape?
14. There are no air blockages?
15. The slides are in good shape? Diaphragms are solid?


Boy, I don't know what else to cover! The plug reads are big. You can get an idea no matter how dirty the plugs are. If it stalls out, and they are white or just dry, you may lack fuel. If they are wet when it stalls, you may have a spark issue. If they are sooty, and dirty, you lack air.

 

[waterman]

Two other simple points to consider is battery charge and fresh gas. In the last month I have pulled my hair out do to poor gas (would not even run in my lawnmower) and a slowly discharging battery causing all sorts of idle and starting problems. Not sure it is your problem but do eliminate the obvious first.

 

[UncleMike]

Sorry guys, I was doing factory tours all day to prepare for a video script I've gotta write.

So if I go down there right now, start her up and let her stall out like normal and pull the plugs, we should get a good read?

Should I clean the plugs first? If so, how?

 

[UncleMike]

You are probably sick of questions that you have already been over, but lets start at the beginning anyway...

Jethro, I will answers as many questions as you want as many times as you want as long as it leads to a well-running bike.

1. Gas cap vent is ok as you said

I took it apart and cleaned it twice. Something to mention though, when I take the bike off the centerstand after she's been running for a while, for instance when parking it for a second to open up my garage door after coming back from a ride, I can hear the cap venting. However, the stalling issue is still there even with the cap off.

2. Petcock flows nicely

Just tested it again yesterday. Flows nicely.

3. Fuel line is 5/16" ID? As you asid not kinked.

Brand new. Not straight, but not kinked, either.

4. Vaccum line is free and attached

Brand new line. Also not straight, but not kinked either.

5. Float bowl gaskets are sealing well? This is an often overlooked air leak.

Brand new gaskets from the carb rebuild this spring. However, the idle adjustment knob has a bracket holding it on that attaches to the second or third float bowl, I can't remember which. Since the screw is not longer to accomodate for this extra bracket, could that inhibit sealing?

6. Float heights are correct?

All set to around 22mm, all within a mm of each other.

7. The little port at the side of the float bowl for the starter jet is free?

Took the carbs apart again when I had them off to install the new boots. Cleaned out that port and the main jet that the slide falls into as well while they were off.

8. The starter jet tube is clean and clear?

Don't know what this is, but the carbs were completely disassembled and rebuilt this spring with all new o-rings. Bodies and jets were all soaked for at least 18 hours, if not over 24.

9. Float needle seats were cleaned? Filters are clear?

Don't know what the float needle seat is, but those little filters that go under the floats was clear.

10. Pilot jet was removed and is clear?

Yes? I did it according to the carb cleanup series.

11. Emulsion tube was removed and cleaned?

See above.

12. All jets and needles are stock sizes?

How would I tell?

13. Mixture screws are cleaned and in good shape?

Looked good to me.

14. There are no air blockages?

Tell me how to check and I'll let you know.

15. The slides are in good shape? Diaphragms are solid?

Sure thing. Besides being a little dirty, the internal components to the carbs looked/look brand new.

 

[Jethro]

By air blockages, just mean the airbox intake vent isn't blocked, and the air filter is fairly clean.

The jets all have numbers stamped on them, but if you bike had a stock pipe and stock airbox when you got it, I seriously doubt the jets are different from stock.

Man... I just don't know what else to suggest!

 

[UncleMike]

By air blockages, just mean the airbox intake vent isn't blocked, and the air filter is fairly clean.

The jets all have numbers stamped on them, but if you bike had a stock pipe and stock airbox when you got it, I seriously doubt the jets are different from stock.

Man... I just don't know what else to suggest!

Intake vent isn't blocked and the air filter is new this spring.

Tell me what I should do to get a good plug read. Some of the terminology is confusing.

Can I go down there right now and start her up and when she stalls pull the plugs and give a read? Or should I clean them first? If so, how?

 

[UncleMike]

Two other simple points to consider is battery charge and fresh gas. In the last month I have pulled my hair out do to poor gas (would not even run in my lawnmower) and a slowly discharging battery causing all sorts of idle and starting problems. Not sure it is your problem but do eliminate the obvious first.

Brand new sealed battery and fresh gas. I still ride this thing quite a bit, and it goes through a tank quite often. This one is only a few days old.

 

[UncleMike]

Okay, plug reads. I was impatient. Sue me.

I started her up. She required full choke and idled first at around 900rpms, then slowly climbed to around 3000 over about five seconds or so and stayed there for about 5-10 seconds before slowly loosing rpms until she stalled.

Pulled the plugs and here's what I found.

#1 - Light tan firing tip. Slightly moist with gas around the first few threads but the firing tip and insulator were dry.
#2 - Brown firing tip. Slightly moist with gas around the first few threads but the firing tip and insulator were dry.
#3 - Light tan firing tip. Slightly moist with gas around the first few threads but the firing tip and insulator were dry.
#4 - Brown firing tip. Slightly moist with gas around the first few threads but the firing tip and insulator were dry.

I know the answer is here, I just don't have enough experience to find it.

Could the carbs really suck those float bowls dry after just 20 seconds of idling?

~Mike

 

[DimitriT]

Check you battery. Hook up a voltmeter while this problem is happening. Try to hook it up to the leads attached to one of the coils. I want to know what the voltage is while its idling right to when it dies.

I agree with everyone that it sounds fuel related but let's eliminate this possibility too.

If the bike idles at 1500 with the idle knob turned out for 10 seconds its got to be hitting a fuel flow issue. If it had a vacume leak it would just not start or would run on choke. But it would run consistently for more than 10 seconds.

 

[UncleMike]

Check you battery. Hook up a voltmeter while this problem is happening. Try to hook it up to the leads attached to one of the coils. I want to know what the voltage is while its idling right to when it dies.

I agree with everyone that it sounds fuel related but let's eliminate this possibility too.

If the bike idles at 1500 with the idle knob turned out for 10 seconds its got to be hitting a fuel flow issue. If it had a vacume leak it would just not start or would run on choke. But it would run consistently for more than 10 seconds.

This problem has persisted through two batteries, and the latest is only a month old sealed battery, but I'll check it anyway.

Thanks,
Mike

Voltage when bike was off: 13.08v
Voltage when turning to "on": dropped very quickly down from 13 to about 12.3v and was still dropping when I started the bike.
Voltage when bike was idling: Jumped up to almost 15v and kept climbing up to almost 17v, at which point the rpms had already started falling and then it stalled.
Voltage went back up to 13.54v at that point.

 

[DimitriT]

At the very least you now know that your RR may need attention. 17v is too high and is an indication of a failing RR. I can't imagine that this is affecting the coils in some way, though. Try disconnecting the RR and run on the battery alone. Check the wires and connectors attached to the RR for signs of heat.

 

[UncleMike]

At the very least you now know that your RR may need attention. 17v is too high and is an indication of a failing RR. I can't imagine that this is affecting the coils in some way, though. Try disconnecting the RR and run on the battery alone. Check the wires and connectors attached to the RR for signs of heat.

Just what I need, another problem!

I've got a backup Honda RR just for this very eventuality.

Thanks,
~Mike

 

[UncleMike]

Took the carbs off, confirmed the pilot jets were stock, cleaned the hell out of the pilot circuit and slapped 'em back on.

Now she's POURING white smoke out of her exhaust. Perhaps I did something right and she's a bit rich now?

~Mike