One for the pro's. 03 f5 bog issues, 03 f5 bog issues?
On the last trip up north my sled developed a bog when I hit the throttle from a dead stop. The blog is not like it's loading up....it's more like a rapid miss. The exhaust even sounds different when it does it. If I get the sled up to about 5800 to 6000 rpm and then mash the throttle it pulls fine and sounds normal. I just did a compression check and both cylinders are @ 105 lbs each. The sled has 241 hrs on the hour meter and 7K miles. I believe the motor was rebuilt just before I bought it 2 years ago.
My son and I took a look at the HCS archives and see that someone else has had the problem. There was no definitive out come as to what the problem was.
My cluthes, belt, drive shaft bearings, idlers, track, plugs are all newly replaced. I did start running premium gas to see if that help...and....it did for about 10 minutes. Then it sarted doing it again. Over the summer when we do our full PM and replace worn and normal wear parts, my son did say he did pull the main jet on one card to see what size it was.
This past trip to NY...we thought it might have been jet/temperature related...because it was real warm......in the high 40 to low 50's.
Today it was cold out so I figured I'd fire it up and see if thee problem was Temp related. The problem still exists.
As far as plug color.......one is black and sooty...the other has a slight bit of brown and sooty. They have always been black from the day I got it. I never had a need to re jet.....I didn't want to fix anything that wasn't broke. The sled has always run well and was reliable. This year I started storing the sled in my 3 sled trailer when not in use. Today I put it in my heated garage to see if I had a moisture or ice issue. The inside of the trailer roof sweats alot.
If any of you folks might have some input.......I can sure us some help on this before I get rammie rippin and tearing and possibly surpassing the problem.
Thanks in Advance!!
Thissideup

if sled has exhaust valves they probably need to be cleaned or ajusted

Thanks...! Yep...checked the cable lenght...servo cycle......valve freedom of movement.......still the same.
I stored it in a heated garage last night. I'm going to fire it up shortly to see if something thawd out. I'll let you know.
Thanks!

change your plugs and also the plug boot ends-they tend to go bad-especially one with over 7k on it....

Thanks.................FOUND THE PROBLEM First I checked the choke cable, rod and lever. Found that only one carb is being choked. I have no problem with that. This way I won't load both cylinders up on initial start. The set screws on the acuator rod and carb choke plungers were all good and free of any need to be concerned. Pulled the air horn and inspected the air box. It was clean as a whistle. Pulled the pipe to sight down into the exhaust ports and take a look at the front side of the pistons and back sides of the cylinder walls. Looks like the top end will need attention after this season.
I pulled the belly pan, drained both carbs and pulled the float bowl inspection nuts to check the main jets. Went looking every place that we were during pre-season PM and that was suggested by the past and present posts. The left carb main jet was standing up in the inspection nut. Go figure................!!!!!! Replaced that main....checked the right one and it was a little loose........tightened it up............AND SHAZAM!!!!!! I'm back in the saddle again. Runs great!
Took your advice and cleaned up the wire and boot ends.....replaced the plugs ...again... Put some grease in the boots...they were sooty. All is well! The sweet smell of APV and a good running sled makes me horney for a real noreaster.
Thanks to all who gave this issue a thought. I just might get some sleep tonight!!!

regards,
thissideup