Bogging in First Gear

[DocFree]

I have spent much time reading on this forum and want to say thank you to all you who post so much info!  So here is my situation.  Last night I did my first oil change on my own.  Everything went fine using the instructions from this site.  I also removed the tank and installed a new K&N air filter (with the restrictor ring).  After I was done I went for a short ~10mile ride and it ran perfectly.  This morning I rode to work ~15 miles, again perfect.  But on my way home tonight the bike was wanting to bog down in first gear when starting from a stop.  The first time it happened I thought I had accidentaly started in second gear, it had that kind of feeling, where you have to give the bike much more gas than normal to get it going.  But it happened after the second stop when I was sure I was in first gear.  It seems odd to me that it ran so well last night right and again this morning, then pulled this business on my way home.  The only other thing I noticed is that the idle seemed a tad bit lower than before ~1200 rpm, my bike used to idle almost spot on 1500 rpm.  My concern is that something I did may have effected it.  Any ideas?  2001 GS500, 9500 miles.  I used castrol 4T 10W40 oil for the change.  THanks!

[scratch]

Idling at 1200 is ideal for this bike (+ or - 100rpm; preferably +).

Sounds like your a little fast on letting out the clutch.

[GeeP]

Highly doubtful you did anything to it.  Check your oil. 

Check to make sure the choke control is completely "off".  Push in the enrichment slide to be sure.

Beyond that, I can't think of anything.  Let us know if it persists.

[Chosen777]

Hey, I just wanted to see if the OP ever figured out what the issue was. I am having the same issue, bogging in first gear.

Thanks!

[The Buddha]

Possible 2-3 causes. In decreasing order of likeliness.
1. Clogged air filter - yea have to check this - maintenance issue vs actual problem ... 
2. Choke staying open.
3. Float too high.

Possible if you mis stated the problem - an intake Vacuum leak - Bog isn't right for describing this, more like a raspy dry feel with a loss in power.

Cool.
Buddha.

[slipperymongoose]

It's a return from the dead! Lol. Start by doing the checks suggested then report back.

[Chosen777]

Possible 2-3 causes. In decreasing order of likeliness.
1. Clogged air filter - yea have to check this - maintenance issue vs actual problem ... 
2. Choke staying open.
3. Float too high.

Possible if you mis stated the problem - an intake Vacuum leak - Bog isn't right for describing this, more like a raspy dry feel with a loss in power.

Cool.
Buddha.

1. I guess I probably should have mentioned that I have the K&N air filter. It appears to be pretty clean. I just got the bike and the previous owner installed the K&N sometime within the 8-10 months that he owned it.

2. I have made sure that the plunger on the side of the carbs is actually opening and closing with the cable. So that seems to be fine.

3. I guess this is my next step, open up the carbs and check the floats.


I should probably mention too that the bike has trouble staying running at idle. Sometimes it idles fine, other times the rpms will slowly go down until it eventually stalls.

[Chosen777]

Alright, I pulled the carbs tonight and opened up the bottom to make sure there wasn't any debris blocking the float needle from closing and stopping the fuel flow. Everything seems to be really clean and I didn't see any issues at all. Another thing that I forgot to mention is that gas has been peeing out the air filter (which I think is a result of the float needle not seating when the bowls are full. It is fine when I'm riding it but it is when I stop that it starts pouring fuel from the air filter.

So I guess my next question is how do you check/adjust the level of the floats? They dont have any fuel in them or anything so I think they are okay. I just don't know how to check the level or adjust them.

Any help is greatly appreciated!

Thanks!

[oneNonlyTu]

Silly question, but is your petcock on the "ON" position? With vacuum not going to it at stops (little vacuum from idle) it shouldn't be filling the bowls enough to overflow. I have fuel starvations and have to use "PRI" and if I forget (not often) Then it overflows.

[Chosen777]

Yeah, I keep the petcock set to ON unless I'm having the fuel starvation issue and then I set it to PRIME but always switch back to ON. The guy I got it from discovered a post where people were asking how to get the float needle seat out. Mine just fell right out when I took the floats off so I'm wondering if fuel is leaking around it since it is so loose.

[cheetahman]

It might be time for you to consider rebuilding the carbs and re jetting to reduce lean fuel mixture conditions.  I don't think the seat should just have fallen out.  Mine remain seated due to the o ring friction.  Sounds like that's your leak from the air cleaner.  That would cause extreme rich condition at idle.  The rebuild kits are like 25 bucks per carb and include the o rings and new needels and seats as well as some gaskets.  Good luck.  Oh.....and the carb articles on this web site show how to do this in great detail. 

[jestercinti]

Sounds silly, but...
Do you have enough gas? 
Tank vented properly?
Plugs ok?
Idle mixture screws/idle speed ok?
Carb to airbox sealed tight?

[Chosen777]

Sounds silly, but...
Do you have enough gas? 
Tank vented properly?
Plugs ok?
Idle mixture screws/idle speed ok?
Carb to airbox sealed tight?

Yes to all of that...haha

[jestercinti]

I only mention cause its happened to me.

[Chosen777]

Let me ask you guys this as well...it seemed like the needle was pretty loose in the seat. Should it be relatively tight around the needle? It seemed like the needle was just flopping around in the seat.....

[Chosen777]

Anybody?

I was actually going to buy new seats and needle valves but the website I was going to get them from is now out of stock. I guess I will have to wait until they can get them back in stock. They were a lot cheaper there than any other site I can find...only $8.50. Everywhere else I have looked they are between $40-$50 each.....

I think tomorrow I'm going to try to adjust the float heights and see if that alone helps....I have a feeling that they are way out of spec and not letting the valve close and fuel is just flooding the carbs and cause it to come out of the air filter....

[Chosen777]

This evening I pulled everything apart again and I really noticed that the float needle valve seats are extremely loose. I think I am just going to try to replace them. There is no way they are holding back gas as they are. I'm sure that is the issue at this point...