80 Liquifire performance upgrades

[luvzvintage]

hi guyz
This soundz really good and am considering it...just wondering if and how many guys have done this and what they're experiencing?

regardz,

Lloyd Neufeld







Greg,
Sounds like you've got the engine built and sealed up correctly, including the carbs, so here is what I *strongly* suggest that you do to this machine to make it REALLY run hard! I've had two 80's L/F's in my day and each of them were total performance turds when set-up to factory specs, where I couldn't stand to ride them because of the sluggish performance that I thought was unacceptable coming from John Deer's flagship sled of that day.

Like you, I was VERY disappointed with the performance and if you've read any of my past threads/posts on this board over the last 1 1/2 years, you'll find that I'm all about performance and efficiency no matter what I'm working on, as it's just my way as part of my profession/career. Follow my instructions here based on what I've personally done to BOTH sleds I've had and you'll have a new machine, where your "riding experience" this year will now be much better...


1. Cylinder Heads:
Ditch the low performance, low compression stockers that come on the John Deere Fireburst Kawasaki's and install a set of late 70's - early 80's Kawaski Invader heads instead. The bump in compression not only bolsters low-end torque, but it makes the engine purr along much nicer at all engine speeds. Plus it's **FARRRRRR** more responsive to throttle input than you ever thought it could be.

2. Ignition Timing:
Increase the intial ignition timing by approx. 3*-4* by turning the Stator back in the opposite direction of normal engine rotation, by placing the little timing mark tip on the Stator housing to the left (or top if you will..) of the timing mark on the case by 2mm. This will ***REALLY*** wake up the engine, make it easier to start and make it massively more throttle responsive also. Plus, you can still use 93 octane pump fuel.

3. Track:
The John Deere specs for track tension adjustment is just ***WAYYYYYYY*** to damn tight for that heavy duty, thick, Yokohama rubber track these L/F's use, where if you adjust it to the factory specs, it puts a ***LOTTTTTTTT*** of unnessary drag and additional load on the engine that eats up a TON of power! First, set the tension to factory JD specs, making sure it tracks straight on the bogies by running the sled in the air so the track can spin freely. Then loosen the tension adjustment bolts 2 full turns from that point and lock them down. You'll not only notice the sled will coast much easier when you let off the throttle, but you'll not have that artificial "braking" effect like you had before when the track was dragging, due to the tight JD specs. Do this upgrade and you will have free'd up a lot of power, the track will run cooler, the Hyfax's and drive belt will wear longer and the clutch won't have to work as hard to get the sled moving from a dead stop.

4. Secondary Clutch:
Ditch that junk, stock 44* single-slope L/F helix and install a 38*/44* dual-slope helix from a Sportfire instead. Then set the spring tension to the tightest hole (#4 if I recall correctly) and then preload the secondary spring 1 full turn after that before you bolt the helix down to the hub. This upgrade will let the engine rev out further before the shift to put the engine in it's peak powerband sooner AND it will backshift much quicker also when you're in heavy snow or under a lot of throttle load. The sled will be MUCH more spirited and you won't believe it's the same machine...

5. Gearing:
Last, but certainly not least and if you don't listen to anything else I've already said above, ***LISTEN*** to this!!!!!! GET RID OF THAT STOCK JUNK, JUNK, JUNK, HIGH RATIO TOP SPEED GEARING IN THAT THING.....PERIOD!!!!!!!!!!!!!!!!!!! The 80's L/F's were mostly equipped with 1.55:1 final drive gearing, making the sled a ***TOTAL TURD*** off the line, because the engine had to really lug hard to get "on the pipe", hence the common L/F bog everyone (including me) complains about. Install a final drive gear set from a 1980+ John Deere Trailfire 340 sled instead, as they were equipped with a 2.16:1 ratio to deal with the low power output of the baby 340 Fireburst fanner Kawi engine. This upgrade will make the biggest improvement of the performance of the sled over anything else I've said and your L/F will ***NOT***, I repeat, ***NOT*** have the dreaded "bog" any longer... It will climb on the pipe right away, scream to redline easily and launch that thing like you never thought it could!!


Trust me on this Greg, as I've done it now twice myself and all of these modifications/upgrades ***REALLY*** work very well without negative compromises. Parts are cheap, easy to find and you won't believe the new-found performance of this sled when you're done. Plus, the durability of the sled won't be negatively affected either... The performance improvement of the total package comes from the sum of the selected upgrades/modifications working in tandem with each other, so don't skimp out and do only one mod and not the other, thinking that it will be "good enough", because it won't and you'll be disappointed...

This is the way the factory should have done it and In my opinion, JD missed the performance target big-time by setting it up to perform "lazy" the way they did. The 1980+ L/F could have been a legend in performance for it's day with just a few tweaks that could have made that sled a real screamer!!

Good luck with your project and I said before coming from my own personal hand in doing this ....THIS WOKS!!!!!!

[Jimmy]

If you use a engine out of a kawasaki that has the high compression heads, is the timming already set ahead the 2-3 degrees or do you have to do that yet? jimmy

[Kurts]

I don't know that I'd get to carried away with the compression increase and the timing increase, but everything else seems reasonable.

[tjsdad]

Just from experience, not trying to step on anyones toes, but I have burned the ring locating pins right out of the pistons with hotter timing, Invader heads, and must of been crappy fuel. I no longer run the Invader heads, and use stock timing as the benefits were not near the risks ( that may be why Deere chose a different head ). It was a little spunkier, but to me, not worth the sacrifice in dependability. Like stated above, Clutching, studs, track adjustment, secondary cam and gearing is where you will notice gains. A HSR ignition, 82-84 clutching and gearing is the best route in my opinion....just sayin'....Gotta remember fuel is not the same as it was in 1980. I had fresh 92 in it when I lost the pistons, but then again, how many people are really filling their vehicles with 93 these days when fuel is 3.90 a gallon?Not me. It can go bad in the ground as well in your tank.

[cmr]

Hi, have an 1980 liquifire and want to up grade track thinken that the drive sprokets from a trail fire have the right pitch. Has anyone done this and will it work or is their a better way to get a track that has more meet on it?
Thanks Chris

[JD600]

cmr,

First off, WELCOME! I'm not sure what you mean by "meet", but the Liquifire is a heck of a lot more reliable and a ton tougher than any trailfire track. So much so that a lot of guys put Liquifire tracks on their Trailfires. Will it work? It sure will, but if its traction you're after, your best option is to stud the track you have.

DE

[cmr]

Sorry what I am looking to do is put a newer track 15x121 and the cog pitch on the trail fire looks to be the same as the new ones where the liquifire is not.So Looking to see if anyone has done that or is their a track that I can purchase with taller lugs that would fit on without changing the drives? looking for more for the I500 race.
Thanks Chris

[liquitisplit80]

[quote="luvzvintage"]hi guyz
This soundz really good and am considering it...just wondering if and how many guys have done this and what they're experiencing?

regardz,

Lloyd Neufeld



Lloyd,
Have you tried any of the upgrades yet? I would like to know if anyone has and what the results are. Thinking about doing this on my 81 so I'm looking for parts. I dont want to mess with the engine but the clutch and gearing mods sound reasonable. What would the 2.16:1 gearing ratio work out to be tooth wise? There's too many to choose from in the parts book and they dont tell what the gearing ratio would be. Standard gears are 21 top gear 39 bottom. Whats the formula to work it out? Also, what is the pn. for the 38/44* dual slope helix? JD parts doesnt list it for the sportfire.
Any help would be appreciated.
-Roy

[Mr. Deere]

Seems to me there is one key ingredient missin? CARBURETOR SETTINGS! If you mess with the compression and timing wouldn't you Also want to richin it up?

[JD600]

What would the 2.62:1 gearing ratio work out to be tooth wise? There's too many to choose from in the parts book and they dont tell what the gearing ratio would be. Standard gears are 21 top gear 39 bottom. Whats the formula to work it out? Also, what is the pn. for the 38/44* dual slope helix? JD parts doesnt list it for the sportfire.
Any help would be appreciated.
-Roy

Take bottom sprocket and dived by the top sprocket and that gives you the top number of your ratio. The bottom number is always 1. For instance, 39/21= 1.86:1. JDParts lists AM55127 as the Sporty helix. Hope this helps.

DE

[liquitisplit80]

Yes that does help Dustin, thanks. Now for my next question - how does the pitch of the chain affect gear ratio or does it? I understand pitch is the length of the link. I always thought this only made the chain fit more comfortable around smaller sprockets. Is this so?
Roy

[JD600]

Yes that does help Dustin, thanks. Now for my next question - how does the pitch of the chain affect gear ratio or does it? I understand pitch is the length of the link. I always thought this only made the chain fit more comfortable around smaller sprockets. Is this so?
Roy

Roy,

To my knowledge, Chain pitch length is an industry standard, and Deere only used one "pitch length". When you hear guys talking about different pitch length chains, they are actually talking about the number of "pitches" or links that the chain is comprised of. The chain needs to be sized appropriately for the sprockets. All of the chain lengths are listed with the sprocket combos in the fine tune manual.

DE

[liquitisplit80]

I gotta get me one of those fine tune manuals! Thanks Dustin!

[Sprailfire340]

I gotta get me one of those fine tune manuals! Thanks Dustin!

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