1990 exciter 570 problem after carb cleanings - Page 2 - Snowmobile Forum: Your #1 Snowmobile Forum

Yamifan66 · 10-26-2012, 12:41 PM

Just got back from tinkering again. It's runs as long as keep on the throttle once the gas burns off from pressing the throttle it just dies out completely so as long as gas is conduit out of the main jets it runs. I know the pilot jets are clean I could see right through them. Any other suggestions? And btw the idle screws are all the way in and still no idle

yamadad4 · 10-26-2012, 01:40 PM

you sir, have an odd issue going on.

just for clarity, when you prime it and hold the throttle on at your 4000 rpm, will it keep running?

good fuel and enough in the tank? fuel switch in full on and not slightly skewed? you have no running history prior to you pulling the carbs? throttle cables are properly adjusted?

the idle is befuddling assuming the slides are in proper. the air screws are on the right side of the carbs. i would take a close look at the pulse line.

stick with it, you will figure it out.

Yamifan66 · 10-26-2012, 02:11 PM

hold the throttle at 4k it stays running.good fuel and enough.switch is on. no running history it sat for many years. throttle cables have a little play on the bars. slides are 100% correct now. messed with air screws and it made it run worse. what is the pulse line? also it will not start without a shot in cylinders.

**RJ Gleason** · 10-26-2012, 04:54 PM

Pulse line is the hose that connects the fuel pump to the engine base and that is what powers the pump.

yamadad4 · 10-26-2012, 05:19 PM

yep, and it should be located on the lower half of the crankcase just below and inbetween the carbs.

when at low rpm, if theres a crack or deviation in the pulse line, it wont draw fuel. you are basically overcoming that by priming and holding the throttle.

a long sitter like that sled, you may also take a closer look at the crank seals.

Yamifan66 · 10-26-2012, 05:27 PM

Ok that will be my next thing to check out. Seals seem to be ok but it's kinda hard to tell. What are the signs of bad crank seals? There's no oil in the bottom end so I'm not sure what to look for. If they are bad does the case need to be opened?

yamadad4 · 10-26-2012, 08:46 PM

if you can get it to run at a slightly lower rpm, spraying some ether, carb cleaner, or even wd 40 towards the seals can give you an indication. if the rpms increase, its sucking air and its a bad seal. easy to get to the clutch side seal, you pretty much have to do trial and error on the recoil side. i have often times found the spring portion of the seal dangling behind the clutch.

i believe yours are the lipped seals, meaning they extend inside the crank halves. its been so long since i worked on an exciter i honestly cant remember if the cases need split or not.

your experiencing a few of the signs of bad seals. more so just starting to deteriorate vs fully shot.

check the pulse line and go ahead and check the fuel pump. you can check the fuel pump with a mighty vac type pump is you have access to one or you can almost get the same results by adding a different longer line to where the impulse line would attach to the pump and suck real hard. a clean hose is best to avoid flavor. by sucking on this line, fuel should move through the supply lines to the carbs. of course you will see better results by unhooking the lines to the carbs.

Yamifan66 · 11-09-2012, 05:19 AM

Quick update. I pulled the fuel pump and there was definitely pressure coming out of the pulse line from the motor block when pulling the sled over. The fuel pump diaphragms looked good so I'm not sure what the problems could be here. I pulled the carbs again I'll give them another look to c if something clogged up again. If I was to hook up a primer would this bypass the problem? Anymore ideas much appreciated got our first snow in Maine today!

Yamifan66 · 12-05-2012, 11:52 AM

hey guys im almost wondering if this is a clutch problem now. I clean carbs again pulled fuel pump and just reinstalled everything. It seems to idle on its own now but very high. On full choke it idles around 4500-5500, no choke 3500-4000. i noticed as soon as i hit the brake enough for the clutch to disengage it starts to die immediately. it acts like it will not run if the clutch disengages. Also with no choke it sounds like it is idleing on one cylinder. just a constant engine sound instead of a typical two stroke sound. when at full choke it sounds like its running on two. any help much appreciated.

**RJ Gleason** · 12-05-2012, 12:20 PM

Easy test, pull a plug wire and see if it keeps running the same of quits.

yamadad4 · 12-05-2012, 08:25 PM

the engine should run correctly without engaging the clutch. in other words, it should idle at normal speed and accelerate up in rpms without hesitation.

if its idling up using the choke it sounds like your leaning out. if its still revving beyond idle without the choke, one would assume a fuel delivery problem(carbs or cable adjustment)

rethink the carbs or check for an air leak.