Please help: Engine bogging when revved

[Tyrant171]

Alright, I'm really hoping that you guys can help me out here, because I'm about to just take this damn bike to a mechanic and probably get ripped off big-time.

A friend of mine who has worked with bikes for a very long time recently rebuilt and re-jetted my carbs for me (the bike didn't work when I bought it......which was probably like 4 months ago). I also installed a fuel filter in the line at the time. Other than that, I have not done anything to the bike other than routine stuff (oil change, etc).

The bike seemed to be running fine, but I always had to have the fuel lever in PRI, otherwise, if I had it on ON, the bike would die after a couple minutes of riding it. Some have said that that's a vacuum problem...but I checked the little vacuum hose and everything seems fine. Always having to run it in PRI isn't the problem that I'm posting about here, but I figured I might as well state it.

The big problem that I'm having now started late one night after I was getting off work. I rode the bike to work, not 5 minutes from my house, parked it, set the lever back to ON (as to avoid leakage like I would always do) and went inside to work. I came out about 7 hours later (around midnight), went to start up the bike and it barely responded. After playing with it for a while, I finally got it to start up, but it wanted to die really badly. When I tried to ride it, it kept bogging and sputtered some. I managed to be able to ride it back home, but I had to do it with very little throttle, the whole time in 1st gear.

So, now that's where I'm at. The bike seems to start up fine, although my friend and I noticed that it smells oddly like coolant when the bike starts running.....strange. When you twist the throttle, the RPMs don't go up at all, and you have to twist it very slowly to get it to rev at all. When you try to apply normal throttle it just bogs and sometimes dies altogether. I can manage to ride it around a bit in 1st, although I can barely rev the engine at all. No matter what, the RPM gauge shows nothing. Also, like I said before. the air smells slightly of coolant when it's running.....I'm just mentioning that because I feel like I should.

I took the bike apart this weekend and attempted to see if I could pick out anything that could be wrong with it. I had replaced all the fuel hoses before, and I decided to do it again when I took it apart, just in case. Alas.....I put it all back together, and no dice. I'm really not the best mechanic out there, if you can't tell. I only know the basic stuff and am really lost here (and also broke, so going to a mechanic would be a tragedy for me).

Anyway, god bless anyone who took the time to read that, and THANK YOU SO MUCH to anyone who has a bit of advice to offer.

*sigh*

[Rema1000]

If the choke were stuck on, then it would start OK, but could die when you give it throttle.  Maybe the choke cable got disconnected, or the slide it pulls got hung-u.

[micron64]

thats what my bike was doing when it wasnt getting as much fuel as it needed. maybe check if it runs better with a full tank and without the filter, or maybe check that both the floats are allowing fuel in the bowl. but really i dont know much and if someone disagrees with me i do too.

[Kerry]

i dont know much and if someone disagrees with me i do too.

Now that's humility.  Thanks for making me grin.  

[vfrocket]

maybe the little o-rings up at the top of the carb next to the diaphragm are missing???

Just a guess.

[dgyver]

Sounds a lot like lack of spark or not strong enough spark. Clean the connectors in the wire harness to the coils. What color are the plugs? While the motor is idling, pull each of the plug wires and see if the motor dies or keeps running.

Also, is the filter installed in the correct direction? Also, is it sitting horizontal in a way that an air bubble stays trapped in it? If so, try moving it vertically or remove it completely.

If you are smelling something fluid related, there are only 2 fluids in the GS....gas and oil.

[scratch]

Is there gas in the vacuum hose? If so, there's a hole in the fuel selector diaphragm.

[Tyrant171]

Thanks for all the input, guys!

I'm glad you gave me a lot of different ideas.....but I don't really know where to start now. :p

What should I do first?

[conflicttheorist]

Look up the fuel hose routing.  I had the same problem when I attached the small vacuum hose to the carb overflow spout (which is located right in the middle) instead of the right one, which is on the side of one of the carbs (a metal spout v. a rubbery one).

[Tyrant171]

Nope, the vacuum hose is hooked up correctly.

[poormanracing]

check your spark plugs...see if its fouled or not....

there might be a vacuum leak somewhere or adjust your float height...i had a bogging problem months ago...the culprit...the carb diaphragms...had a tear/hole in it...bought a pair...running hard ever since