My '02 700 hasn't been running normal lately. Ever since I bought it, the exhaust header always turns cherry red from the motor to about the start of the bend that goes back to the muffler. I accepted this as being somewhat normal. About two weeks ago, a feul line froze because it would only run slightly above idle with the choke pulled all the way out. I put some feul line de-icer in it, and it ran alright after that.

Just last week on the lake, I was running it pretty hard in fluffy snow. After a while, it idled worth crap, and throttle response wasn't very good. If I pulled the choke out, it would die intsantly, so I thought it was way rich. I figured some snow got in the airbox and melted and somehow got into the carb. It has also acted like this when it is foggy out, so I figured it was due to the moisture. The thing I don't get is why moisture would cause this. After I normally shut it off for a little while, it runs fine. This is what it did when I got home.

Then just last night, I could barely get it to run at all. The choke had to be all the way out for it to idle, but it could run at some higher RPM's with the choke in, but it did it roughly. This told me it was running lean at low RPM's if the choke needed to be all the way out, but slightly lean at mid range. The other problem was that the exhaust was red just about all the way to the first mounting point after about three to four minutes of below 10 mph in low. I could bearly get up a 20 degree hill in low while feathering the choke to try to make it run right. I had to take three tries at it before I got up it. I took it in the garage and was going to tear it apart because I had enough of this crap. After tearing the panels off and the airbox lid, and inspecting for any physical damage, I started it up to see if the idle adjustment would make a difference, and it idled like a champ. It was sitting for about 15 minutes. I then took it for about a three quarter mile run and it still idled fine, but the exhaust was a little more red than "normal". After taking it down the road to open it up, (about one tenth of a mile) it idled like crap again. I then took it home and parked it. This morning, it ran like it should have.

I don't know where to start since the problems are all pointing to something different. I'm pretty sure it is in the carb, but I don't know where exactly in the carb, and I am kind of intimidated by them. Another thing that should be stated is that there is some oil in the coolant. I don't know where the leak is, but I don't think this would cause the problem.

Sorry for rambling on, but I hope somebody can help me. Sorry if I don't reply right away; I don't get on the internet more that twice a day at the most. Thanks for your help in advance.

 

IMO put the stock exhast back on and see if the problem is really the carb ... glowing red isn't a good sign, also most sounds like the exhast is clogged.

what octane fuel are you using? try going with the lowest octane fuel you can find.

 

It still has the stock exhaust and air filter on it. In fact, it has stock everything. I use 87 octane gasoline. When it runs right, it keeps up with my dad's 700 EFI, so I don't think the exhaust is clogged.

 

sounds to me like your running rich...

could your fuel filter be blocked due to the fact it idles hard after running a long time or full throttle for a while after you turn it off it gets a change to get fuel back into the line.

could also be bad jetting

 

I think it sounds more lean than rich. You may be sucking excess air through a leaky gasket somewhere causing an overly lean condition.

 

Sorry ... i've only seen RED hot exhaust pipes on after market exhaust pipes with overly rich carb settings or a blockage collecting and burning fuel ... i'm [img]i/expressions/face-icon-small-confused.gif[/img] about what it could be. Maybe call your local dealer and ask?

 

Check the carb boot from the carb to the cylinder - they have been known to tear. If you haven't replaced the fuel filter ever then do that too. Also, if the plugs have never been changed you can do that too... plus it's a good way to see how your engine is running. Lastly I would say check your fuel pump.

 

in order for the header to get red hot, it has to be lean....

there are a couple of possibilities.....lack of fuel somewhere, since you had the fuel line freeze up, that isn't normal at all, gas just doesn't freeze, water does....so, replace your fuel filter before you do anything else, sounds like it is starving....

if you didn't change jets at all, then something else is messed up....

dave

 

My guess is you're running LEAN. Lean always makes the engine a heck of a lot hotter than rich, and that's what damages it as well.

As previously said, check for air leaks EVERYWHERE. If you have stock jetting, and are near sea level and colder than 40ºF or so (check your manual), you need to re-jet (running lean).

 

Thanks for the info. I will look into the feul filter, plugs, and check for any leaks. The boot in between the carb and the cylinder has been replaced once by the dealer because it had some pretty gnarly cracks in it, but it never ripped. That was about a year and a half ago. Thanks again.