90 Indy 500 LC Idle Speed?

[benamen]

Mag side piston tweeked a while ago and now have it back together and trying to set the idle. When the engine is cold starts up and idles at about 2200 and then idles down to 1400 when warm which is a little low. I can't seem to find a speed inbetween those two numbers. When making small adjustments, speed jumps from 1400 to 2200 when the speed does change. At 1400, it idles quite smoothly. Are there any adjustments to the carbs that I should look at?

When I tore down the engine for repairs, I noted there was no oil flowing out of the supply lines. After re assembly, I attempted to purge the oil lines but could not get any oil flowing. Took the line off the exit side of the filter and no flow. The oil flowed quite well when I removed the filter. Took the filter apart and there was only some clear gunk clogging the screen. 3 years ago, I had changed this oil filter, drained the oil tank due to the fact that the sled had not run in a while, and topped the tank off with blue Poo oil. Just used up the last of the 4 litres of the Poo oil. Is it normal to have the filter plug off on a machine that does not get a lot of use? Should I make replacing the oil filter part of my annual maintenance on all of my machines?

 

[BB454]

Idle

I think you are just right on your current setting but if you want it higher then that's up to you. How are you adjusting the Idle? If you are using the thumb screw on the side of the carb then the problem may be that the screw has bored into the slider a little. That will cause the loss of fine adjustments. Those sliders are brass and you can probably file the whole slot down to get rid of the hole made by the screw. I don't think that will make any difference in the way the carb works. Just make sure you file down the whole length of the slot evenly so you maintain the same adjustability.

Sounds like you may be getting moisture in the oil from condensation. If you aren't going to run them for a couple of years then new filters wouldn't be a bad idea.

 

[ElectroTech]

Try adjusting the pilot circuit dont worry about the idle at first just get the throttle response working well, then dial in the idle. Also ensure that the carbs are mechanically synchronised at a minimum, but a full synchronisation will help alot in overall running and fuel economy.
As for the oil filter, there must have been a reaction of some sort, pull the tank and flush it out, replace the filter and blow out all the lines. Once you have it all back together hold the oil pump lever wide open, being carefull not to kink the cable.

 

[WyoUltra]

Have you tried blowing out your carbs? Like taking them off the engine and then blowing air through them? I had to do this on my Ultra, the middle cylinder wasn't getting gas. So I took the carb off and unscrewed the bottom of the carb and blew air through every hole on it. Now it runs fine, and it was similar yours it would idle high for a while and then it would drop. I don't know how much exactly, because I never checked, but it has solved this and it doesn't idle like that any more, and it runs a lot better.

 

[benamen]

Picked up this sled 3 years ago went through the carbs and put in new needles and seats. Replaced the oil and fuel filters. Friend (who is a tech) came over and setup the carbs for me. Sled ran quite well and is usually started every month or so in the off season.
I adjusted the idle speed using the thumb screws and balanced them with a vacuum guage. Other than knowing how to adjust the choke settings, I have no knowledge as how to mechanically or fully sync the carbs. Any input on this is appreciated.
Thanks for all the input.

Ben

 

[WyoUltra]

Also another thing on mine was my choke was fubared. I unscrewed the end of the choke that goes in to that carb and the spring was all messed up and tangled, it was also pretty dirty.