$20 bucks on the line....$10 to winner/$10 to GSTWIN

[werase643]

bought a bike
friend found it for me
never talked to the P.O.
Friend said it ran bad and had been sitting for a couple of months on P.O. front porch.

bike.....2000 SV650 with 30,000 miles, slip on, and lots of bling!!!!

I tried starting it..... didn't want to run....drained about a quart of water out of the tank, cleaned the carbs, stock jetting with exception that the mains are one size bigger.  air screws are 2.5 turns out.  drained and cleaned the tank, cleaned the fuel pump. new plugs, synched the carbs

the water got in the tank due to the drain next to the cap had come loose from the tank....broke the weld?  I RTV'd it put on a tank bag with plenty of tools for the shakedown run.  turned out to be several runs.....

here is the STUMP THE SQUID QUESTION.....the bike runs fine for about 30 minutes then starts acting weird.....stumbles at low throttle (<4k) but will clear up with a down shift and WOT.  If I let it sit for 1 hr, it will cool down and run good.....till it heats up and starts running bad again

WTF is wrong with the bike??

this thing has been kicking my a$$ for a couple of weeks.  I will answer diagnostic questions only.

[Rema1000]

Clogged line to evaporative cannister or otherwise building-up of vacuum within the gas tank?  If you pop open the gas cap after you stop, will it run fine again without waiting for an hour?

[werase643]

45 lookers.....no squid answers....come on....it's for a good cause....

[rt_fz1]

It has a vacuum actuated petcock.  That might explain why it runs at WOT but not below 4K.  The valve may need to be cleaned.  I'm not sure why it would wait 1/2 hour before acting up though.     Hope that helps.

Rich

[werase643]

actually it has a vacuum actuated fuel pump....cleaned it....still have the problem.  thank you for playing...and your help.

[GRU]

the needle needs to be lifted higher (a little)

i had the same problem with my GS....i raised the needle by 1 washer (2 total) and it worked

also might wanna raise the float hight and go at 2 turns out insted of 2.5

just 2 cents  

[gobstopper]

Have you completely emptied and refilled the gas tank, so you're sure there's no water in it still?

Have you replaced the plugs and checked the ignition system?

Perhaps the carbs need rejetting with bigger pilots since you have a low throttle problem?

PS- If I win, give my 10 bucks to GStwin.


Wait a minute---Is there coolant in the radiator?  That would cause a problem due to heat, and WOT would be better than low throttle because with a slip-on can the mains are probably a bit rich.  Hmm.

[cernunos]

The only problems with running rough below 4-5 grand that I personally know of have been due to carb icing and a pinched drain hose or supply hose from the fuel tank. This was what I heard from the guy who sold Bebe the White Owl. The carb icing was supposedly a problem mainly in colder climate models but J said it does occur in warmer climates with right humidity. Sounds plausible I guess...I used to fly light fixed wing aircraft and they have carb heaters to prevent icing. And belive it or not, icing is more prevalent at temperatures around 50-60 degrees F than lower because lower temps don't support enough moisture in the air. What is the ambient temp you are running at? Also, your altitude. Wish I could ride, still browsing the forum at times.

C.......

[rt_fz1]

actually it has a vacuum actuated fuel pump....cleaned it....still have the problem.  thank you for playing...and your help.

Petcock too.  Actually called the vacuum fuel valve.  It draws vacuum off the same carb as the pump on the opposite side of the carb.  I had problem with it on my SV race bike.  I installed flatslide carbs with no vacuum port.  I didn't hook up the vacuum line to the petcock and no fuel flow.  I ended up attaching it to the manifold boot after cleaning up the petcock and presto!  I still don't know why it would start only after warmup.   :dunno:

[werase643]

just so ya'll know i have solved the problem....before I posted this thread!
this is kinda why i posted this....to make ya think.....

keep the ideas coming.....it's all there everything i had to work with for the super deduction of the problem....and in hindsight....it makes total sense.....pain in the ass.... but we love bikes for different reasons....and the blue ridge parkway was beautiful today!!!!!

[werase643]

136..... come on....think.....
i'm guessing the P.O. had same problem.........

i'll look this over again wed afternoon

have fun  

[Reknelb]

Valve clearances to tight. Once it gets up to temp there is no clearance and the valves are staying open.

OK....what do I win??

[sprint_9]

Something with the choke is messed up.

[i3randon12]

1,000,000 dollars!!!  :dunno:    :dunno:    :dunno:    :dunno:                                

[GRU]

you changed the rear tire???  :lol:
j/k

[70 Cam Guy]

Something with the choke is messed up.

That's what I was thinking.  Did someone forget to turn it off once on the road?

Ever notice how once you learn a thing or two about engines, you always think dooms day when something is wrong?

[cozy]

I'm gonna get away from the fuel system and say it's (was) a charging problem.  Battery, shorted wires, or stator from the water which undoubtedly went other places if it got into the tank.

[octane]

Bad needle valve in a carb.

[MacDuff]

Are you missing a needle in the carb?  

MacDuff

[dgyver]

The slide holes are drilled too big