I recently bought a stock 2003 Scrmbler 500 4x4. On my first trip to Dumont I shredded my belt. After reading a few posts I decided to go with a 700 belt and ordered a dalton black drive (primary) spring and a hpd violet driven (secondary) spring. I did not find an easy to understand explanation ref the driven spring placement in the holes on the helix and sheave. When I removed the driven pulley, the spring was in the #1 hole on the helix and the #2 hole on the sheave. The first thing I noticed was that the stems on the stock spring were in the same position top and bottom, the stems on the hpd violet springs were about 180 degree different from top to bottom. I called Rick Ritter just to make sure this was right, he provided great information over the phone. Because of the different stem locations on the hpd and stock springs, the driven pulley did not go together the exact same way so my marks were not lined exactly up after the sheave was pre-loaded. When I put everything back together I put the stems of the hpd spring in the #2 hole on both the helix and the sheave and pre-loaded the sheave 1/3 of a turn. On my test drive I instantly noticed a better low end hook-up, but topped out at 41 mph on a flat hard packed drit road (per GPS). I allowed about 30 minutes of riding with the new belt and springs before I returned home to make adjustments.

I again removed the driven pulley and now placed the stem of the hpd spring in the #1 hole of the helix and left it in the #2 hole of the sheave. I took it out for a test, the low end hook-up is still a big improvement from stock. I'm not going to pretend that I fully understand this system but it does not seem that changing the stem placement in the driven helix and sheave effect the low end hook-up. Now it made it up to 52 mph on the same dirt road and it did not sound like it was in first gear. I also rode for about 30 minutes this time.

Now I replaced the hpd spring stems in the #1 holes on both the helix and the sheave. This test drive was exactly what I was looking for. It easily hit 60 mph, though I did not push it I think it was almost at its new top speed. The low end hook-up still great. I took it up a few sand hills and there is a noticable improvement. I'm not sure if this will change further as the belt wears in.

For Christmas, my wife bought me a K&N Filter, a FMF slip on, and a jet kit (not dynojet). She will not give it to me till Chritsmas day. I think the slip on has a disk system so I'm not yet sure how many to run. Any advise on this would be great. I am at 2000 ft so not sure yet about re-jetting.

I hope this information helps.

Andy

 

Thanks for the good info and let us know how you like the FMF. I think I will probably use your info as an initial setup for mine.

 

A6079
I spoke with the dealer when I bought my 06 Scrambler last week and he told me that all carburated Polaris' are set for 2500 ft. I believe this to be true based on my experience here in Reno 4700ft. When I took delivery it was pretty sluggish. When I put the White Bros. pipe on with the K/N it was much better. I started jetting the pipe with the stock 8 discs. After testing it seems to run best with 11 discs and the airbox lid on. When I took the lid off it lost alot of power. So my quess will be that your jetting will be close at 2000ft. as long as you don't open the pipe up too much.

 

When I took the trip to Dumont that shredded my belt I had drilled four 1/2" holes in my airbox lid. could be in my head but it seemed to run better. I have read on other posts though that home-made airbox mods hurt, so I will plug my holes and up my main to a 160 then see where I am with the pipe and filter. I don't fully understand the disk system on the exhaust so I'm sure I will have to give a few test runs. I am not looking to get more top end out of the bike just get the mid range up a little for sandy hill climbs.

Andy

 

Andy,
We do alot of duning as well. How did you shred the belt? Are they problematic? Should I just go and buy a 700 belt as back up? PLease advise. Let me know how your jetting works out as I am planning a trip to Glamis this year.
Thanx
Cam

 

Cam,
I'm not sure if it's a problem area, I have only had the bike for a short time. It is a 2003 and I can tell you from the look of the bolts that hold on the clutch cover, the belt that went was the original belt. When the belt went I had been in the gas for close to 45 minutes on the hills. Might not seem like a long time but it is when you're up and down on the sand I think it is. I plan on carrying a spare belt in the future when I go to the dunes.

I will post all my jetting and pipe adjustments, might help someone.

Andy

 

Just put the FMF pipe on with the K&N. When I first put on the pipe I was not sure which way the disks went on due to poor instructions from the factory. I installed them first (all 9) in the direction that exhausted towards the front of the bike which did not seem right after I did it. I still started the bike with that set up with only a change in sound. I flipped the disks to exhaust out the back. This time as soon as I started the bike it started to backfire when I gave it gas. I removed the carb and changed the main jet to a 160. On my bike there was a plug that covered the mix screw, I drilled out the plug and then turned the screw all the way in and backed it out 3 turns. When I took it out for a ride it seemed to be just right. I took it over to my test / sand hill and there was more mid range power. There seems to be no change on the top end. The mid range change is noticeable and worth the money. The bike goes up the hill faster now, losing less speed in the sand When I returned home and pulled the plug it looks like I am running a little lean. I am going to pull the main and increase it to a 162.5 and leave the mix screw at 3 turns then see if that fixes the problem. I am running all 9 disks and did not do any experiments with fewer disks. When I look at the muffler is set up, I think that the fewer disks installed the more restrictive the exhaust flow. The Sound is great with 9 disks.

Andy

 

Andy,
Cool, thanx for the report. As a rule the more discs = more flow through and louder. The beauty of the discs is that you can tune the bike for altitude without the hassle of re jetting. The other thing I do is drill holes in the airbox lid which you can tape up when you go to lower altitudes. This also help airflow, especially with more discs in. The higher the altitude the more holes in the airbox and/or more discs in the pipe. It is the lazy way to rejet as I hate rejeting this bike. Have you found an easy way to do it? It took me 2 hours last time by the time I took the plastic, tank etc. off.

 

I wouldnt advise to drilling on a 500 airbox.The CV carb has to have a certin amount of vacum to opperate correctly.When doing airbox mods you have to mod the slide and the jet tube to get it right.