Hey guys - just thought I'd post this here as well, in case any of you have an idea of what could be wrong. I posted this on another forum, so forgive the cut-n-paste. My AC has been bogging down under load, (up hills) since I brought it in for the 300-mile service on July 7th. I did some maintenence on my AC 400 yesterday and I'll pick it up where I opened up the air box. Thanks.


" Everything looked okay upon first glance, (a little dirty, but not bad). I removed and lightly cleaned the filter, put a cover on the intake and cleaned out the box. Put everything back together and took a ride into the state forest. It's worse....

This thing totally bogs down under load, (up hill) and now sputters on the high-end. It also seemed to be running hot. I stayed on strictly dirt roads and after about 6-miles, I shut her down and the fan just ran and ran, (a cigarette's time+). I drove her home, with lackluster performance. It ran well on the 1-mile of pavement between my house and the forest, (hit 50mph with some sputter). It also seems to be burning gas...I have a reputation for being "wordy" so I'll try and wrap this up with some points in the hopes that it may trigger something who may have gone through the same thing, or works on these machines...here goes:

- Upon removing the airfilter, I noticed is was wet inside - looked, felt and smelled like gas

- The vent hose coming from the tank was pinched severely between the intake section, (by the seat) and the tank.

- The filter was fairly clean, but did have a thick black smudge underneath

- I'm using the last of my 89 octane with SeaFoam added

- This 400 has not run properly since my 300-mile service.

- Before tonight, performance was good-to-excellent except uphill and was excellent all around before July 7th


I'm not one of those "blame the dealer" guys, but it is true. The first day I rode after picking it up from service, it started the uphill bog-down. The only thing it hasn't done that it was doing, (twice) is shutting down for no apparent reason....Any ideas? "

There you have it. Thanks in advance for any tips/tricks/ideas. I will say that I'm not the most mechanically inclined person on the planet, but can manage. I was hoping to avoid another trip to the dealer, as I'm not completely confident in their abilities, (they are the only game in town). I'm 1/2 tempted to trailer this thing over the border to New York, but would like to avoid that as well...Take care.

Mark

 

Does the machine spit and sputter the entire time even on flat ground? If your vent line was plugged/pinched that could cause it to suddenly die or quit. Have you checked your oil level after it came back from the dealer?

 

It spits and sputters on flat ground now- but didn't before. Oil level is perfect and clean. Called the AC dealer and they asked me if my choke was on. It's not and I haven't used it. They were surprised by that stating that AC's are "cold blooded". Going to clean out the air filter and run the choke line to see if it's hung up. Can't imagine why it would be, but you never know...

 

On the work order...what exactly did they touch?
If they say they did the valve adjustment, then thats a good place to start. Sounds like the intake valve may be too tight.
Its not that difficult to do, and its pretty simple to just check it.
They have the a/c service manual, on ebay real cheap, itll give the procedure and the specs in there.
When its bogging down...whats the throttle opening....wide open, half open or where? If you pull on the choke, when its bogging...does it get worse, or better?

 

Sounds like your carb got some dirt in it and is either flooding over or at least plugging an air bleed or something of that sort causing a rich condition. I would suggest a carb removal and teardown for general cleaning. Check the float level also. Quite often just tearing the carb down, rinse everything out and flush the passages out and reassembly will solve these kind of problems. Pull your spark plug and see if it is black or white. Black too rich, white tool lean. I say too rich.

 

This vent line yer talkin about. I have an 06 500 auto, about a week old. i was peekin around a bit and i noticed there is a hose, probably the vent line, and it looks like it has been melted in half. i can't find where it goes to, but it looks like it might come from under the battery. Is this a big problem?

 

If you are able to start the engine without the choke, there is for sure an over rich problem. Check the spark plug, if it is black then it is too rich. Try running it without the air box top and if that doesn't do it try removing the air fliter and try a short test run (both these moves lean out the engine). If these fix the problem, then you need to find where the extra fuel is coming from. If they do I would be tempted to go back to the dealer and tell them that since the service the problem has been fair constant.

 

You know? I don't think I ever posted the fix for my Bog-down on here... It hasn't done it in quite awhile and I'll tell you that in many ways - everyone was right. There were a few things going on - if you're interested, here's what happened:

First, the drain hole in the belt housing was plugged with crud. I did semi-swamp this bike on 2 occasions, so it looks like I was never really draining anything out. It was dumb thing to overlook. All I needed to do was poke a wire up there to clear it.

Anyway, the belt housing was dry, but there was a thick wheel of caked mud/belt dust on the clutches. Cleaned that out. Checked the belt specs and it was at 29.5mm I couldn't get a straight answer on what service spec is, (new it's 30.3mm), but I left it alone and air-gunned the rest of the crud out of the housing.

Next, I checked valve clearance - they were at odd numbers on the feelers, but within spec.

Next, I took off the seat and ran the vent line - pinched between seat and airbox snorkel. Rerouted line.

Next, I was just about to take the carb out and noticed that when I pulled the throttle cable cover off, the throttle was just a hair above 3/4 at WOT. Adjusted play

Next, I cleaned and oiled filter

It ran much, much better after that, (still bogged down a little up hill, but ran super in the flats), but the final fix did not come in until a few weeks later. Just for kicks, I ran the quad for about 3 hours in low gear. I have since reverted to using low in most of the trail riding I do - I keep high gear for connector roads and open fields...

I may be wrong, but my guess is that two things may have happened: (A) that like the infinitely wise Bear said - I had crud in my carb and the extended time in low range heated up the engine enough to burn it out. (B) That running in low gear for so long seated my belt better in the now clean clutches.

In any case, it runs like an almost champ now -no more bog down, though I still think a little on the rich side. I wish they'd come up with a way to adjust mix, without pulling the carb - I can't get my fat fingers underneath there... [img]i/expressions/face-icon-small-sad.gif[/img]