Aftercrash problems

[miki__]

Last week, I had a lowside on my GS. Here is the video for the curious:

The damage in the crash wasn't major; scratches on the headlight fairing, broken mirror, bent handlebar and a broken pulse generator cover.

I managed to get all the parts needed and have now put the bike together. However I have now found some additional issues:

1. The bike revs up as normal but returns to idle very slowly. As in the revs climb up as usual but are slow to go back down or even just stay high.
2. The bike heats up really quickly and is slow to cool down.

Do you guys have any ideas as to what is going on?
Any help will be appreciated.

Cheers,
miki__

[robfriedenberger]

Sounds like you have an issue with either your choke and or you have a vacuum leak, I'd start by inspecting your choke levers operation and your carb boots. The drop most likely just knocked the carb out of the boots or disconnected your choke cable.

Glad your ok from the drop, it would do you some good practice fast stops. Judging from the video it looks like you grabbed to much front brake. Its hard to tell in the video so I'm not bashing you at all. We all can use a little more practice.

[miki__]

I checked the choke and it seemed fine at first but after taking it apart again I noticed that was stuck on (the issue No1 resolved). However I have now got another issue. During the crash, the pulse generator cover snapped off and so the bolt snapped too. I had to drill them out in order to replace the old cover and it seems I may have made a hole in the case as I am now leaking fuel from one of the bolt holes 

I will now have to wait for a new case.

P.S. could that have been the reason for overheating?

[miki__]

Regarding the crash, I explained what happened exactly in the description of the video. It wasn't that I grabbed too much front brake, it was because I tried to change the direction without letting go of the brake first.

[Watcher]

I am now leaking fuel from one of the bolt holes 

Fuel or oil?

If oil that is one thing, but if fuel is coming out of the lower end of the motor that could mean several things more.  Primarily that fuel is overflowing from the carbs into the cylinders, dripping past the rings, and entering the crankcase.
If that is the case, it can cause serious damage to the engine.


A quick way to tell if fuel is in your oil, take the dipstick out and put a drop of oil on the back of your hand.  If it sits there it's just oil.  If it spreads out through all the little wrinkles in your skin it's been diluted with fuel.
Or just smell it.  It'll smell like gas.

[miki__]

Oil, just a typo.

[robfriedenberger]

Glad that resolved your issue, yeah other than a new crank case cover you can see if a machine shop can fill it for you.

I did t read the video description because it was embedded.


Sent from my iPhone using Tapatalk

[Watcher]

Well, if you did drill too far getting the bolt out and made an opening between the threaded hole and the crankcase, I would imagine some thread sealer like teflon tape on the bolt could fix the problem at least temporarily.

You don't want to be riding around with an oil leak, but it could be worse.  At least it's not a hole in the side of the case.

[miki__]

Don't worry, I'm not riding the bike right now. Case should be here by Friday, fingers crossed.

[Watcher]

Yeah, new crankcase really is the best option.

Good luck in the build.

[miki__]

Well, after changing the case, no more oil leaks I do however still have the problem of not having power.

I decided to check the carbs and one of the little white plastic things broke.
http://www.ebay.co.uk/itm/SUZUKI-GS-500-E-2007-CARBS-/190961783187?pt=UK_Motorcycle_Parts_13&hash=item2c76359193

Do you guys know what that part is called, I am looking at the plastic white(ish) bit at the bottom of the carbs in the picture.
Will I be able to get one or am I going to need a new carb all together?

[DoktoroKiu]

Well, after changing the case, no more oil leaks I do however still have the problem of not having power.

I decided to check the carbs and one of the little white plastic things broke.
http://www.ebay.co.uk/itm/SUZUKI-GS-500-E-2007-CARBS-/190961783187?pt=UK_Motorcycle_Parts_13&hash=item2c76359193

Do you guys know what that part is called, I am looking at the plastic white(ish) bit at the bottom of the carbs in the picture.
Will I be able to get one or am I going to need a new carb all together?

The circular bits with the hoses connected to them and whatnot?  This page has them as part of the cover assembly (part number 32): http://www.cmsnl.com/suzuki-gs500-f-2004-2006-usa_model16027/partslist/300550.html#results

I would guess that this part is somehow related to the PAIR system.

[miki__]

I think we are on the same page regarding the part.

Could this be the cause of lacking in power?
What is it responsible for?

[DoktoroKiu]

I think we are on the same page regarding the part.

Could this be the cause of lacking in power?
What is it responsible for?

I don't have my manual at the moment so I'm not sure what it does precisely, but the top part of the carbs does need to be sealed.  When you open the "throttle" you are actually only opening the butterfly valves.  The real throttle slide is opened via the vacuum generated by increased flow of air into the engine (this also pulls up the jet needle, releasing more fuel).  It has something to do with allowing the engine to control how much throttle it gets based on how much it can actually use, and is called "constant velocity" carburetion.

So if your plastic bits are leaking then one (or both, I'm not sure if they're connected or not) of your carbs will have a harder time lifting the throttle slider.  It makes sense that you would feel a lack of power, because essentially you're not getting full throttle even when you think you are.

If you haven't already done so I recommend Googling "CV Carb" and watch the 2:09 video that (should) pop up.  It's kind of fast so I had to watch multiple times to catch everything, but it is a great explanation of the basic principles.  I knew nothing about how my carburetors worked only a month or so ago, so it must work a little.

[miki__]

Ok, thanks for the information. The video is surprisingly simplistic but explains carbs very well. Thanks for that as well 

[DoktoroKiu]

No problem.  I checked my Haynes manual last night and it calls this piece the "piston lift control valve", and they directly state that it is not possible to buy this part by itself.  But, I believe Adidasguy (RIP) highly recommended some type of plastic rebuilding material that might be able to fix this (I believe it was in a thread about repairing fairing cracks).  The Haynes manual also shows how to test its components.  There's some seals, a diaphragm, and a check valve under the plastic, IIRC.  You'd want to make sure those aren't damaged if you take the repairing route, but if they are you essentially will be on your own to find replacements.

In my understanding it is used to get more precise control over the throttle, but I'm not sure exactly how as the check valve would only allow you to control it one way (either opening or closing).

I would check this thread http://gstwins.com/gsboard/index.php?topic=59064.15 if there are no required emissions testings in your area.  Apparently you can remove the newer "features" and the bike will run in a kind of "safe mode" where it uses the carbs like the older models as a failsafe.  You could then get a secondhand old-style black cap to replace your broken one, or just seal off the broken one completely (you'd have to seal all other unused ports as well).

Looks like you have several options if this piece is your real problem.