Started up my mach 1 yesturday and found some weird idling behaviour. It was idling a bit high (~2100rpm) for a bit, then fell to 1800rpm where it should be. Then I lifted the front end and put it back down and the idle jumped back up to about 2300rpm and stayed therefor a while, then came down to 1800 again. It would sit at 1800 but keep blipping up to 2100-2200 now and then.

Is this normal or a symptom of something?

Thats a sure sign of too low of octane level in your fuel!!

No, I'm just kidding buddy. Not really sure, but how long does it stay at the higher revs.

I know my doo, will take about 10 sec to idle down after letting off the gas. Stays at 2200 or so, before dropping to 1800. I've never worried about that.

FishHog

when its started, it goes up to like 3000rpm then eventually comes down, but what bothered me is that it wouldn't stay at 1800...it kept jumping up to 2200rpm. PLus, every time I moved the sled ( I was turning it around) the idle changed. Thats what bothered me. I don't think it did this before. Could it be too lean in there somewhere? Air leak?

Tighten the carb boots.

They might be loose from who ever last serviced it.

Speaking of idling, what is the normal idle range for a mxz 600?? I have mine around 2500rpm. Is that OK?

Sounds to me like your air screws are a little lean, try screwing them in 1/4 turn at a time, if you go to rich it will load up on you.[sputter on take off]

Originally posted by Machzzzz1@Nov 15 2002, 05:21 PM
Tighten the carb boots.

They might be loose from who ever last serviced it.
Started up my mach 1 yesturday and found some weird idling behaviour.

Have the carbs been cleaned yet ;)

Originally posted by Rocketman@Nov 15 2002, 05:17 PM
Could it be too lean in there somewhere?
Ya Im betting on a dirty carbs :doh:

My first question would be how old is the gas? Bad gas will cause that to happen, as will dirty carbs. If you have not cleaned them out in a while, it may be time...

Sledcrazy- 2500 seems way high. I leave mine around 1500-1600, but it is really personal choice. The only thing I would be worried of is letting the thing sit there and idle for a long period of time because of all the extra heat.

Yeah...as far as I know the carbs have not been cleaned and the gas is from last year ;) But that can't be it :0:

Rocketman, if you put fresh gas in it, I would look at carb synchronization and/or cracked carb boots (underneath boots). My carbs are always synched (I always synch. idle screws with very small drill bits, then use nail polish to mark the screws), then I use 2- 3/8" drill bits under slides and slowly press on throttle until drill bits move at same time. If they don't, I adjust cables on top until all slides move drill bits at exact same time. Once this is done, I open throttle full and check to make sure all slides clear top of throttle bores. As for carb boots cracking, I'm on my third set in 5000 miles, which in my case is worse because of the amount of times I've taken carbs off.
Hope this helps !

Rocketman. Does it do it when you turn the bars, or when you move the sled itself? Could be your choke is hanging up too.

Limskii. That track held up mint. 240 chisels in it. Not one pull through all season. Ended up with 185 hp in the improver. Chased electrical problems all year. Did you make any COSDRA events this year?

Yeah..that's when I noticed the funny idle..I was turning the sled around and the idle would bounce up every time I dropped the front end.

First step is to pull the carbs and clean and sync them.

Krusty, I had thought about setting my sled up for Sturgeon Falls, but it was cancelled. I didn't really have time anyways, as I worked on my truck all summer (a 1988 Ford F150 ext. cab, short box 4X4 that I bought for $1000, but needed lots of work). I'm in the process of installing a 136"x 1.25" predator 9819 track with 108- 1.325" megabyte studs down the middle along with a rail extension and I will also extend the tunnel myself. I'm happy that track held up with no problems for ya !
What kind of electrical problems on your sled ? (stator, rev limiter, coils, shorts ?)

Steph, as you know the base motor is a 98. I didn't want to deal with the limiter and DESS, so I swapped it out for a 97 system. The only thing I didn't switch was the coils. That turned out to be the issue. As well as the PTO being out of phase.

Rocket. You cleaning? ;)

Nope...selling...for now...I'll clean it if I keep it ;)

What you gonna steer if you sell em both?