Skorpion tour 660 bogs down and dies

[Snapjaw79]

Hi, I recently bought a 2001 skorpion tour 660 and replaced the spark plug and fuses and everything was going fine... until i noticed that the oil was low, so i purchased sae 15w-50 as specified under the seat and put some in. I checked the dipstick and it was closer to the minimum line but i figured that was fine. After riding around for about 30 min I noticed i was losing power and started riding back home. It died. Wouldn't start. so i took the seat off and checked everything and the oil level remained the same (still between the min and max). after sitting for a minute i thought well maybe I'm low on fuel and set the fuel line to reserve. I put the choke on and it started again. Made it back home with a very strange feeling throttle response, found that i have plenty of fuel but now it dies every time i ride. I'm very frustrated because before putting the oil in it was great and I'm pretty sure I did everything correctly but I'm a newb so any advise would be greatly appreciate...

[DAVID THOMPSON]

you are suffering from bad gas
the stuff in the usa is nasty
time for a carb clean out and new gas with no ethanol
if you can find it in your area
http://pure-gas.org/
my rt125 just refuses to run proper on the ethanol blend
dave

[Snapjaw79]

ok that sucks haha thanks for the reply. I also just noticed that there are two hoses coming out of the gas tank... 1 on the left (if your sitting on it) goes to the fuel open/closed/reserve valve and the one on the right is not connected to anything. should it be?

[edfmaniac]

Gas in the States may have some alcohol in it but it's not enough to be the only cause for your problems. A good carb cleaning never hurts though.

The second hose coming out of the tank is a drain that allows water collecting around your tank lid to drain out.

Make sure you read the oil change procedure and be sure not to overfill your tank. It's real easy to do if you don't check the levels and top off your oil only when the bike is at full operating temp. That's the only time the level in the tank will read accurately.

[Snapjaw79]

OK thanks, its just a plastic oil tank under the seat and the dipstick unscrews which makes it difficult because it doesnt specify whether to screw it in when checking the level. That makes about a 1/4 " difference in the oil level. also the manual says to use 20w-40 and the bike says dont use anything but 15w-50. Stupid newb problems, I know LOL.

[Snapjaw79]

Okay now I've just noticed that the bike runs smoothly while the fuel is set to reserve, when i switch the fuel to open it bogs down. what the hell.

[billr]

Okay now I've just noticed that the bike runs smoothly while the fuel is set to reserve, when i switch the fuel to open it bogs down. what the hell.

A good carb cleaning never hurts though.

What he said...
Mine was doing similar when I first got it, had been sitting for most of a year. It ran well with a full tank, but once it got near reserve, would not run worth a darn.
Cleaned the carb...lots of gunk in there.
Still had a bit of a problem, wound up getting a new fuel valve for the tank, also. The original was not flowing well.
Search this forum for the threads.
Bill R

[Snapjaw79]

Thanks guys, I really appreciate your responses!

[Snapjaw79]

Well I ran through a tank of gas with some Seafoam in it... The bike is now basically no longer ride able. it idles fine but any pull of the throttle and it just has no power. I got it going about 30 thinking I could just blow something through the system but It feels like its going to blow up or something no bueno. Problem is I live in a very small town with no motorcycle mechanics. I don't have the knowledge to clean the carb so I'm basically screwed. Any ideas?

[Srinath]

I used to do this on GS500's.
You send me your carbs and I'll clean and jet em to your specs and send em back ...
Except, I cant jet a skorpion blind, like I can with a GS500. I had to make a 100 O2 sensor runs etc etc before I can do that.

I can clean and set it to stock and send it back though ... for about $40 labor and return shipping.

Oh, you in continental US ? If not forget it.

Cool.
Srinath.

[Srinath]

The petcock in the tank may be gummed full of crap.
Well, it may have got to the carbs too, but worth checking the petcock, you find it full of muck, you may want to look in those carbs. If its clean in the petcock, you may have a different issue.
Cool.
Srinath.

[harold]

Have you tried hitting the choke when you are riding it? If you are running lean, this could tell you as it will enrichen it. Another possibility is that the choke is not releasing. That could also cause your symptoms.

[Snapjaw79]

well I loosened the choke cable all the way and its not as bad... It seems the choke had something to do with it. Does that mean I'm running to rich? It still looses power and i can't get it above 45mph but its not sputtering and fluctuating power as much.

[harold]

I believe the stock carbs do not have a real choke, but rather an enricher. Do a search here on it, and somewhere you should see how to disable it. If it is on part way, that could cause all your problems. It also should start quickly without it when cold, since it would already be on. That is of course, if your spark plugs haven't gotten partially fouled from running too rich.
To check for lean, you can cover most of your air cleaner with tape or something. That will make it run richer, like the choke was on. If you are lean, then things should get better. If it is worse, than possibly your enricher is not releasing completely.
If you take the air filter off, then it should run a little better if you are too rich, as that will lean it out slightly.

[Linegeist]

I believe the stock carbs do not have a real choke, but rather an enricher. Do a search here on it, and somewhere you should see how to disable it. If it is on part way, that could cause all your problems. It also should start quickly without it when cold, since it would already be on. That is of course, if your spark plugs haven't gotten partially fouled from running too rich.

I think you'll find that most 'modern' carbs no longer use the crude 'strangler flap' method of creating a rich mixture for starting a cold engine. Instead, they incorporate a separate fuel delivery circuit that delivers extra fuel for that critical time when conditions are too cold to support efficient fuel atomisation.

And that's what we're talking about here - efficient fuel delivery to the cylinder, mixed in a suitably combustible ratio. All simple stuff.

Back in a previous life, when I was an apprentice spanner wrangler (sometime around 1968), it was drummed into me that, when faced with weird problem, there ain't no substitute for getting back to basics. With our engines, that's simply compression, a spark (at roughly the right time) and some fuel for the two previous things to burn. Get those right and you'll get a 'bang!' Remove them and you won't. Simple. Take away anything that might create a smokescreen - like the air filter, the fuel pump (just bypass it) and any gadgets, and get the system as basic as possible. Then start hunting, item by item.

You've narrowed it down to a fuel problem and I'd suggest the problem has to be in either the petcock or the carb(s). As you've demonstrated that the petcock will deliver petrol in sufficient quantity when turned on (and assuming you've bypassed that infernal pump-thing and that the fuel keeps on flowing even after 5 minutes have passed) there has to be a fault somewhere in the carb(s).

So strip 'em - on a clean bench and with plenty of spare time to do it in, and clean everything to surgical standards. If you can't find anything wrong, check again - because there's obviously a fault there and you've missed it. Work in logical, careful steps, on a bench, and strip anything that comes apart - even the little sub-assemblies like the float valve unit. In the case of the 'choke' check the rubber ring's not perished on the slide, that it moves easily, that it's seating fully in the 'off' position and that its bscrewed fully into the carb body ...................... and that the fuel level's where it should be. Assume someone with the IQ of fresh road kill has futzed with everything and set everything up as per the book. Then check it all again.

I've resorted to this approach on numerous occasions - laboriously stripping every element, bit by bit. If you do this methodically, you will eventually hit on something that's not as it should be - and the trick then is to rectify this, and carry on in case there's something else. This is what professional techies do - it's called diagnostic fault-finding - and it's not rocket science (unless you're a ballistics technician (or called Werner von Braun) in which case all bets are off) and it almost always yields results. I've even fixed faults with no explanation as to how - but the faults got fixed and beggars can't (in a corner) be choosers.

It's time consuming. It's boring. But it's cheap - and it beats shooting in the dark while using an internet forum in lieu of a manual. Careful, logical fault hunting is a dying art - and one that any classic machine owner really needs to learn.

Here endeth the wossname ............................