Confused, bike runs in afternoon but wont start in the AM

[maro]

this happens on my 650G often, and usually when a drastic change in temp happens.. ie night to mornings.

Valves are correct...

Is it a carb problem. probably. Should I take off my carbs that I cleaned 2 summers ago that perform right on tune with no errors (other than this). probably. Have I found a ghetto work around. of course.

When this occurs, I blow into the left side vent, force some gas into the bowls (yes, I have tried prime) and BOOM, fires right up.

Should I continue doing this. Probably not. But she runs amazing otherwise (as this only really happens in the fall and spring) and I've been busy with the 1100 so....

Here's my thread from last year regarding this: http://www.thegsresources.com/_forum/showthread.php?t=130808

 

[AJKnowles700E]

2mm is not much, 0.10" approx. :-k

I didn't see vent "T"s on the OEM CV carbs I pulled off the 700.

Another thought.

On some of the bikes I have owned that were cold natured I switched from 5K to 1K Ohm resistor caps for the spark plug wires, and it seems to help with cold starting.

Alright, no vent "T"s that is good I have not tried changing the resistor caps yet so that might help. I wouldn't think that 50 deg is cold though and that bugs me too I could understand if it was 30 deg but 50? argh

Alright so......won't start in the morning, but it will in the afternoon ??

How many times has this happened ? Will it ALWAYS start in the afternoon and NEVER in the morning ? Why would this be ? What's the difference ? How is the bike stored ?

Happens every time I try and start it in the morning always starts in the afternoon. What is different, I don't know other than time sometimes the temp is the same in the morning as it is in the afternoon.

How about a simple fix?

Before turning on the ignition, stand astride the bike so it is vertical, switch the petcock to PRI and let it sit there for 3 or 4 seconds.

Then pull the choke into position, ignition ON, and start the bike.

This little procedure often works on cold mornings.

Tried this no luck! Great suggestions but have run it through the cycles

this happens on my 650G often, and usually when a drastic change in temp happens.. ie night to mornings.

Valves are correct...

Is it a carb problem. probably. Should I take off my carbs that I cleaned 2 summers ago that perform right on tune with no errors (other than this). probably. Have I found a ghetto work around. of course.

When this occurs, I blow into the left side vent, force some gas into the bowls (yes, I have tried prime) and BOOM, fires right up.

Should I continue doing this. Probably not. But she runs amazing otherwise (as this only really happens in the fall and spring) and I've been busy with the 1100 so....

Here's my thread from last year regarding this: http://www.thegsresources.com/_forum/showthread.php?t=130808

Tried forcing air through them and still would not start after that

 

[AJKnowles700E]

Bike started this morning!

Bike started this morning!

Well after thinking about the choke cable being possibly strectched out a little and not opening the choke all the way all night and patiently waiting for morning I went out and tried it today. Low and behold it started! We will see if it was a complete fluke or if it will start tomorrow. Of course had to pick up my son today and it was suppose to down pour which it did so I didn't ride it but it started thanks all for all your suggestions and thoughts I will let you know if it starts tomorrow

 

[tejasmud]

Don't know about leaving the choke on all night, but would never hurt. :lol:

Suppose 2mm is equal to half of a choke port, hmmm....could be, but...

Seems like you may have found your ritual.

Just keep doing what you are, ummmm, ahhh..... did.

Really,

There are so many little things that can cause no starts. If the ritual works out, I'd keep an eye on the spark plugs given they usually tell all. Just every once in a while pull them and look. Time usually tells what is going on in the engine.

To me, it sounds like the idle circut is a little lean. But, if "full choke" does start the bike in the coldest weather you shall ride in, it might be just right. When the temp gets warmer it should just bust right off, possibly no choke.

Good to hear you had some luck.

 

[AJKnowles700E]

Don't know about leaving the choke on all night, but would never hurt. :lol:

Suppose 2mm is equal to half of a choke port, hmmm....could be, but...

Seems like you may have found your ritual.

Just keep doing what you are, ummmm, ahhh..... did.

Really,

There are so many little things that can cause no starts. If the ritual works out, I'd keep an eye on the spark plugs given they usually tell all. Just every once in a while pull them and look. Time usually tells what is going on in the engine.

To me, it sounds like the idle circut is a little lean. But, if "full choke" does start the bike in the coldest weather you shall ride in, it might be just right. When the temp gets warmer it should just bust right off, possibly no choke.

Good to hear you had some luck.

Thanks Teja,
not sure what the idle circuit is or how to adjust it but I can check it.

How do you adjust the fuel mixture screws correctly? Could that make a difference too?

 

[tejasmud]

Yes, the idle circut can be adjusted.

This involves the mixture screws/pilot fuel/air screws, heard them called many things, and yes, it will make a difference.

To be honest, I need to look at the OEM CV carbs I pulled off the 700 to tell if the screws control fuel, or air. It has been a while since I have messed with these CV carbs. Mostly have experience with mechanical slide carbs which is what will be going on the 700 when it goes back together.

The service manual if all stock should get you in the ballpark. Fine tuning with the engine warmed up just involves tweaking the screws to find the happy place. Probably not much adjustment is needed given at "full choke" it seems to start.