Odd bogging with my 97 mxz x 440

[Lips97]

Just picked up a good condition 97 mxz x440 for $800 from some craigslist guy. He had it sitting on the shelf for 7 years and fogged it before storage. Brought it home and cleaned out the carbs and started and ran great. The fuel line in the tank was bad so I cleaned out the tank and put in a new fuel line and grommet. Now I've been riding it around and trying to get it ready for Michigan on the 25th I leave. Well it's been acting goofy. Brought it to the track with my cousin as he races and I'd make it around the track once and it would bog down, only revving to about 4800 where the clutch engages and tryst to kill itself. But when I feather the carbs chocking them by hand it seems to kind of pick itself back up. Seems like it's not getting fuel or something. The primer was bad so I replaced that as it didn't prime, which I don't think that would cause an issue unless it could have been pulling air through it..? Just ordered a used fuel pump as no one sells them, and a roll of fuel line and fuel filters. Will be starting with those as I think it would be a fuel problem. Any other ideas would be appreciated.

 

[Slicnic77]

I am having a similar issue with my Mxz 583. I rebuilt the fuel pump and cleaned the pickup filter. Still not getting any fuel to the carbs. I'm going to buy a new primer as that is bad. I'll keep you posted. But look into how much air you have coming out of the crank case vacuum Barb. If you have no air coming out then it is possibly crank seals.

 

[Lips97]

I am having a similar issue with my Mxz 583. I rebuilt the fuel pump and cleaned the pickup filter. Still not getting any fuel to the carbs. I'm going to buy a new primer as that is bad. I'll keep you posted. But look into how much air you have coming out of the crank case vacuum Barb. If you have no air coming out then it is possibly crank seals.

I'll be 're doing all of the lines when my fuel pump shows up. It gets fuel till I believe after I ride it for a bit. Didn't really check to see if it wasn't getting fuel when it bogged down. But them when it does, I put fuel in the carbs, and it will run and do the same thing. Thinking the fuel pump can't keep up when 3/4 throttle or something. Just odd it doesn't do it till I ride it a bit. Seems a little boggy from the get go a little too. But that's not the issue as of now.

 

[BBP]

Could be a plugged or kinked tank vent line. Jet fell out? Some late 90's models had a screen in the fuel inlet to the carbs, might be plugged. When it acts up, feel your cyl's & see if one is cold to isolate the problem to one side or the other. Check for a fouled plug or just replace them.

 

[Lips97]

Replaced the pugs, took out the small filters in carbs. It is running too much oil as I tried running 32-1 . Plugs had oil on them. Cleaned the carbs 4 times and jetted it to 240. Has New plugs, and I will be switching to run 40-1 Already 're did the fuel line from the tank. Motor stays cool enough to hold my hands on it after riding it hard.

 

[jheitzman]

Make sure the vacuum line from the crank case to the fuel pump is not dry rotted and cracked.

Josh

 

[Lips97]

I pulled the motor and am 're doing all the lines and fuel pump tomorrow