80 liquifire power loss,clutching?

440z · Post by **440z** » Wed Jan 31, 2007 11:55 pm

I am working on an 80 liquifire that is having a problem with losing power. The sled starts up on 2 to 3 pulls every time and idles great. When starting out on a flat, it runs good. The clutch engages at around 4200-4400 rpm. The sled pulls itself great and really comes to life around 5800 rpm and doesn't back down. The problem it has though is if you come to a grade and let off and get back on it, it will bog down and lose power and struggle to make the hill. Also, if you start out on a grade;even slight, it seems to have a really tough time to get itself going. The carburators have been set to factory specs and the spark plugs are chocolate brown as they should. The electrical system seems to be working good to. It has a 20 tooth top sprocket and a 39 tooth bottom sprocket. Could the gearing be the problem or is there a problem with the secondary clutch? I really believe that the problem lies in the clutching. So, any help and suggestions would be greatly appreciated.

sledchad · Post by **sledchad** » Thu Feb 01, 2007 2:27 am

If you say it pulls pretty good on the flats no questions asked then it doesnt sound like its in the clutchs but you never know with out looking at it and eliminating other things. I had a simular thing happen with me on my old Jag, would do the same things as you described but come to a hill it would bogg. Found out my intank fuel line wasnt routed to the rear of the tank like it should of been plus my check valve had some dirt in it and cause the ball inside to stick sometimes. So i fixed all of that and it cured it. Maybe yours is doing the same thing i dont now but wouldnt hurt to check.

Rodimus Prime · Post by **Rodimus Prime** » Thu Feb 01, 2007 3:06 am

describe what you mean by slight incline?

generelly under 45 degree slope stock gearing and clutches should handle it easy.

i suspect worn rings myself.

hence a top gear of 21 or 22 top and 35 bottom (stock gearing ) 20 is optional gear.

440z · Post by **440z** » Thu Feb 01, 2007 10:57 pm

When I say the carburators have been set to factory standards, I mean that I have them set to the specifications along with the internal components listed in the service manual provided to deere technicians. Also, the motor has plenty of compression. It has about 100 miles on it since I rebuilt it. I noticed that the secondary has a difficult time returning to the closed position whenever I press the moveable sheave in to take the belt off. I almost have to pull it back to the closed position by hand. I have had it off to replace the jack shaft bearing. At that time, I replaced the plastic wear buttons that the helix rides on. I thought I may have ordered the wrong ones, but I checked my receipt for when I purchased them. There are no binds when I press the moveable sheave in and it moves freely when rotating the sheaves. I have ridden other 80 liquifires and they have not had this problem, they have some bog or hesitation but not like this. Thank you to all those who replied and hopefully I get this issue resolved.

Rodimus Prime · Post by **Rodimus Prime** » Thu Feb 01, 2007 11:07 pm

actually the secondary should snap back on its own.. if it moves freely then replace the secondary spring and see if that helps.

440z · Post by **440z** » Fri Feb 02, 2007 2:25 am

Take it to the Limit, I didn't think you were being difficult at all. I just wanted to say which tech manual I was working out of. I greatly appreciate everyone's input because it gives me ideas to look for when I am stumped. Once again, thanks to all who replied.

Mr. Deere · Post by **Mr. Deere** » Fri Feb 02, 2007 6:54 pm

Mine does the same thing. If it sits i jump on it and it bogs. I lift the back end and it kind moves but i still have to push it along. Will it move on an incline if you push it. BOB

440z · Post by **440z** » Sat Feb 03, 2007 2:00 am

I was reading AAEN's 1999 edition clutch manual and came across this information, AAEN states, "As the sides of the belts wear, it will pull further into the driven sheave in low gear and loop further out around the shaft on the driven sheave. When this becomes excessive, the clearance between the sheave and the belt becomes larger before engagement and the postion of the belt puts it into a higher ratio on engagement.The result is that the sheaves slam into the belt with a jerking motion, but since the system is now in 2nd gear, it tends to pull the speed down and bog the machine off the line before it starts to shift out." Furthermore, AAEN goes on to state, "...The correct center distance should give a belt deflection of approximately an inch. Keeping the center distance too long makes the belt grind around the driving hub and the machine tends to creep. Too short of a center distance means the belt is to far out on the driven and you almost start in "second gear" with a bog and bad low end performance as a result." AAEN then cocludes, "In my years of fixing transmissions that don't work I have seen more than enough cases where a new belt fixed the problem. In a majority of other cases, a good cleaning did wonders."

After reading through the clutch manual a little further, maybe this is what is causing my problem. The liquifire seems to have the symptoms he describes because of a worn out belt. I am going to try a new belt and see whats happens. I'll post again to tell if that was the problem or not.

Rodimus Prime · Post by **Rodimus Prime** » Sat Feb 03, 2007 10:43 am

keep reading

harleysportster · Post by **harleysportster** » Sat Feb 03, 2007 11:34 am

I noticed that the secondary has a difficult time returning to the closed position whenever I press the moveable sheave in to take the belt off. I almost have to pull it back to the closed position by hand.

Did you ever fix this problem. You should remove the secondary and check the setup of the spring. What is the condition of the outer sheave bushing. Rich outlined the installation of the spring very well.

In regards to the secondary, the spring position recommendation is hole #2...then you instal the cam over the post and rotate past one ramp (80 degrees). If you do not prewind the secondary spring...it will not have proper tension. You can look at either technical manual for that...Section 50-15-4 & 5. There should be aprox. 6 lb. of spring tension measured at the sheave rim.

440z · Post by **440z** » Sat Feb 03, 2007 6:17 pm

I worked on the liquifire today and think I got it running correctly. I disassembled the driven sheave, and then inspected everything. Everything is in good condition but I didn't have enough pretension on the spring from when I replaced the guide buttons. So, the belt was burnt a little and will still need replaced but it did run a little better. After riding it, it still wasn't performing like it should. So, I had the air screw set at 1.5 turns and decided to set them at 1.0 turns. This made a significant difference and it performed much better. Also, I dropped the needle one groove and it performed even better after that. I think the cold weather here is affecting things a little. It is 5 degrees right now and the air is very dry. To my amazement though, the sled sat in a non heated garage last night and this morning in three pulls with full choke it started and idled perfectly. I think with a new belt, this thing will really perform well. Thanks to all who gave their input. It is appreciated.

harleysportster · Post by **harleysportster** » Sat Feb 03, 2007 6:25 pm

worked on the liquifire today and think I got it running correctly. I disassembled the driven sheave, and then inspected everything. Everything is in good condition but I didn't have enough pretension on the spring from when I replaced the guide buttons.

Great To hear.

So, the belt was burnt a little and will still need replaced but it did run a little better. After riding it, it still wasn't performing like it should. So, I had the air screw set at 1.5 turns and decided to set them at 1.0 turns. This made a significant difference and it performed much better. Also, I dropped the needle one groove and it performed even better after that. I think the cold weather here is affecting things a little. It is 5 degrees right now and the air is very dry. To my amazement though, the sled sat in a non heated garage last night and this morning in three pulls with full choke it started and idled perfectly.

Check the color of the spark plugs after shutting down the engine from a WOT run.

Deleted User · Post by **Deleted User** » Fri Feb 16, 2007 9:39 pm

i have three john deeres 80-81 liquifires that all do the same thing. i went through the clutches on one of them with no change.(was actually in good shape to begin with).engagement on one is 3600 or so and the others engage at about 4500. and all do the same thing.the gearing is my next step.if stock is 22/35......that has to be the issue.lol.. i do like the setup on the trails though.pulls good for a 25 year old 440. matt

Pion · Post by **Pion** » Wed Feb 21, 2007 2:58 pm

Hello 440z:
I am new to this site, but I have 3 1980 440 liquifires, low end boging can be caused by a worn belt, it should sit damn near flush with the top of your secondary. I also had a problem with it boging on an incline, it drove me nuts, I finaly found out the the in tank fuel suction line had rotted off, and with the tank partilly full on an incline would suck a bit of air. I pulled out the old screen and line, replaced it and it worked alot better.
Did you try the new belt and did it work?

enduro97 · Post by **enduro97** » Mon Feb 26, 2007 2:21 am

Hey Guys, I am working on a 1979 trailfire 440 that has appox. 300 miles on it since new, I cleaned tank, carbs twice, fuel pump, installed new filter and lines. I don't have any good manuals to show how to set up/adjust this carb so I tried to put things back where they where. It starts great and seems to run good from half throttle up but is real boggy on take off/ low speed. I would like to get a copy of a good manual on setting up this sleds carb. but I am thinking that the clutches might be a large part of the problem. I again would like to know how to clean/service and adjust these. I know the belt must be worn some since it rides about 1/4" down in the secondary clutch and also if I open that clutch by hand it doesn't spring right back? Can the spring be weak from setting for so long or does it need a good cleaning/ adjusting? I am interested in this post since it talks about deere installing the wrong gearing in the '79 trailfire? Can this be part of my problem also? If so does any one have the correct gear that deere says to change to? I love this site and all the information it provides! How would I ever know that my sled may have been over-geared from the factory? You guys are great! Are there any other service bullitens or updates that I should be aware of on this 1979 Trailfire 440? I would like to get this going great for the kids to ride! THANKS for all your help, Don. enduro97@msn.com