80 liquifire power loss,clutching?

[Pion]

Hi Don,
I would honestly try a new belt first, if it is sitting down 1/4 inch on the secondary it will create a bit of a bog on take off. the belt should sit flush with the outer edge of the secondary pully.
Pion

[enduro97]

To drive this home...if you look in the Parts Manual for a 1979 Trailfire 440 you will find that it will show 25/39 gearing. The 440 Kawasaki installed in the 1979 could not pull gearing that tall and SIBs, a PIP and 1980 Production changed that. How did it originally get geared so tall? When engineering told marketing that the Liquifire would not be ready...marketing said "we need a model that will at least go 85 MPH"...so that became the criteria...gearing that (by theory) would allow a Trailfire 440 to reach 85 MPH. The drop down to 21/39 gearing was quite a drop and you can see that calling 25/39 gearing "stock" would be correct..

-RICH

Hey Rich, I own a 1979 trailfire 440 (new to me) and it has a really bad bog from idle and low end. I plan to get a new belt as mine is worn and in this post you talk about this model having the wrong gears from the factory. This sled only has a few hundred miles on it since it was new! Should I check the gears and change it if it has the "factory" gear in it? What are the right gears for this sled? Also the secondary clutch does not spring back like it should. How do I clean/ check/adjust this? This sled has sat for a very long time and I may need to clean/ service both clutches? Are there any other important updates I should be aware of on this model? Thanks for your help, Don.

[enduro97]

The change for the 1979 Trailfire 440 was a 66 pitch chain and 21 tooth top gear.

Hi Rich, Thanks for your reply. Since the kids will be riding this would you suggest I change the top gear and chain if mine has the wrong ones? How will I know the pitch of the chain or if I change the top gear I need to also change the chain? Do you have the correct chain and gear that you could sell? I will check mine first and let you know. Also does anyone have a tech manual for a 1979 Trailfire 440 that they would be willing to sell? I will check on ebay also and see what is available. Thanks again, Don.

[grasscutter97]

The change for the 1979 Trailfire 440 was a 66 pitch chain and 21 tooth top gear.

As these sleds are nearly 30 years old, I recommend:

-Verification of all jetting (do this when soaking the carbs...replacement of the pilot jet is often a good idea)

-Verification of gear ratio (do this when cleaning/replacing chain case oil and inspecting chain tensioner)

-Verification of clutch tuning (do this when cleaning up the clutches)

A Tech Manual and/or Fine Tune Manual is very helpful when addressing the above items.  New Tech Manuals are still available from Deere...Fine Tune Manuals come up on Ebay from time to time.

In your case, disassemble and clean your secondary.  There are two bushings to inspect...and the three buttons.  When reassembling, the spring should be installed in #2 hole.  You can check the tension by using a pull scale on the outside rim...I will get the spec and post it.

-Rich

This is the best, most simple piece of advice any new (or old) JD sled owner should be doing.

Well done.