80 LF post rebuild 1st startup problems

[burt87]

Well the copper spray did the trick. That's the good news. It started first pull, I did the coat hanger trick while feathering the gas. Now i'm having trouble getting it to idle. The carbs are in sinc, opening and closing all the way on both, idle screw turned three turns after contacting slide, air screw backed out 1 1/2 after tension was felt. I needed to turn idle screw an additional 2 1/2 turns and it is only tacking at 2000, and wants to die when I try to give it gas. I know that 3 turns is only a starting point, but 5 1/2 turns seems way too much. I'm sure that I have the timing mark right on the money. I saw on a post by pjs that he recomends to advance timing on fire series liquifire's a few degrees. Any help with this issue would be greatly appreciated.

Rob

[guitardude081]

Check your chokes. From the end of the plunger to the step on the hex part of the choke bell (the top of the threads at the hex) both should be set at around 1.25". Your problem may be that your choke is still functioning even in the off position which would flood the motor and cause it to stall.
~Jack

[burt87]

Jack,
That is what I think I have them at, but that's where I'll start looking at first. I know someone on the boards [I can't remember who, but they deserve the credit] suggested putting grease on the choke plunger to see if it was bottoming out. I may need to do that. The choke cable's are after market, that shouldn't effect the 1.25" would it?

Rob

[guitardude081]

When you buy an aftermarket cable, you have to swap over your parts and set them to JD spec. I'd assume that you did that when you got the cable.
~Jack

[pjr]

Well the copper spray did the trick. That's the good news. It started first pull, I did the coat hanger trick while feathering the gas. Now i'm having trouble getting it to idle. The carbs are in sinc, opening and closing all the way on both, idle screw turned three turns after contacting slide, air screw backed out 1 1/2 after tension was felt. I needed to turn idle screw an additional 2 1/2 turns and it is only tacking at 2000, and wants to die when I try to give it gas. I know that 3 turns is only a starting point, but 5 1/2 turns seems way too much. I'm sure that I have the timing mark right on the money. I saw on a post by pjs that he recomends to advance timing on fire series liquifire's a few degrees. Any help with this issue would be greatly appreciated.

Rob

Rob,

Increasing the base ignition timing setting of the stator wil bolster and increase engine performance across the entire RPM range, including idle. However, I don't think that's the problem with your sled right now, based on your descriptions of the issues. Go after engine performance modifications and/or upgrades AFTER you get the basics sorted out first, otherwise you run the risk of hurting the engine; which as you know....can be expensive.

Peej

[burt87]

Thanks peej,
Thats what I wanted to hear. I figured there was something else that needed attention.
Jack,
I did change over the choke plungers from the old cable. The right side has a small pin or whatever it's called on the bottom of the plunger, the left side is just a barrel. Is this how they should be? That's how they were when I bought the sled.

Rob

[guitardude081]

The pin style is not correct but, if both are seated properly that's not your problem. The pin style one is more common on vacuum slide ATV carbs than it is on snowmobiles.
~Jack

[burt87]

It turns out that the one on the right with the pin is only measuring 1 1/8" and is adjusted all the way. The right side plunger is physically smaller(shorter not diameter) than the left side plunger. I'm going to my local parts/salvage guy tomorrow to see if he has one. The left side seems to be bottoming out. Would the idle be that affected with the choke bottoming out on one carb and not the other?

Rob

[burt87]

Well, I am happy to say that my Liquifire is running. I'm guessing that the choke plunger with the pin on it was the problen, although I changed both of them. I was able to go for a short ride tonight. .To think that I almost forgot how much fun it is, since I have been working on this thing for soooooo long. I would like to thank everyone for helping me with suggestions or just words of incouragement the last 2 yrs. I would never have been able to do it withought this site. To think that I almost sold it on evilbay for $350 makes me sick, as you all know too well, I have way more than that in just the purchase price from 12 yrs. ago,the $ spent on parts, and you can't count all the hours. I hope I didn't offend anybody along the way if I chose not to use your suggestion, I respect everyone's knowledge about these fine machines. Finding the link to JD to purchase a technical manual on DVD was priceless.

On a side note, my local salvage/new parts guy has some invader heads in good condition for $20 a piece, is that a fair price to pay for them if I choose to do the performance mods that pjr has written about?


Rob

[Sprailfire340]

Last month I purchased a pair on evil-bay for $20 plus $15 shipping from Canada to MN.