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Discussion Starter #1
I wanted to share something that I discovered while working on the high (20:1) oil consumption on my F5 SnoPro.

After consultation, my dealer recommended that I first attempt to adjust the oil pump. I've always done my own mechanical work and after 23 years of riding Cats, have never returned a sled to the dealer for repairs (knock on wood!). I removed the carbs, and to my dismay, found that the actuator arm was already aligned mith the mark on the pump and that there was little if any adjustment that could be made (even by bending the stop on the pump arm). I was convinced that I had a faulty pump. While putting things back together, I noticed that the slides in the carbs were not pulled clear of the throttle bores at full throttle. In fact, they stuck down about 3/16" into the bores when they should be wide open. I adjusted the throttle cable and reassembled. The lack of performance from this condition was never suspect because I only had 160 miles on the sled at the time. The next day I had an opportunity to ride and set off with extra oil. To my surprise, the low oil light did not start to blink until well after 120 miles. Oil consumption was, and has been, 57:1 (I'll live with that!)

I believe, after some thought, that the slack in the throttle cable was being taken-up by the oil pump. The first movement of the thumb lever was moving the pump arm far before the throttles started to open. At lower throttle openings, the pump was suppling far too much oil. This condition exists on the F5 because of the throttle arrangement that uses a splitter; where one cable goes to the throttle assembly and the other to the oil pump. My understanding is that the F7 uses an adjustable rod from the throttle assembly to the oil pump, making this condition unlikely.

I know that this was long winded. But to those who are experiencing high oil consumption and can't seem to get satisfaction from adjusting their oil pump, check to make sure that the throttle cable is pulling the slides all the way clear of the throttle bores???

It happen to me, so there might be others with the same condition. It's just my opinion, of course I could be wrong.

P.S. - thanks to you guys and especially Rob for the suspension set-up advice. My sled went from barely rideable to a real pleasure. Probably will try the Powder Pros next. Only 1000 miles to date, so not a Hardcore Sledder, but enough miles to know that this is my best Cat ever!
 

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I too had the exact same results as you.I adjusted the cables and also had to open the throttle stop to allow for full WOT and my oil consumption changed from 35-1 to 55-1,I'll leave it there.I can go a full tank and the light doesn't come on,and only needs a half quart or so per tank.
 

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My mistake,I'm going to edit my post and should have said after I adjusted the cable,I had to move the throttle stop back to allow full movement of the slides.Those damn 10mm nuts on the cable were a pain to loosen and tighten back up,theres not much swinging room for the wrench :wacko:
 

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Discussion Starter #5
redF5sp - I'm glad to hear that my thinking was not too far outside the bounds of reality. I was starting to feel guility for extracting so much good info from this forum and not giving anything back. I hope that others find the same benefit as we did.

P.S. - put a little silicone at the point where the APV cable-ends go into the barrel of the servo motor assembly. I found that one of my cables came off at about 250 miles - really killed the top-end. 750 trouble free miles since using the silicone.
 

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After reading this post I went out and checked my five and found that my slides were also slightly short of being clear if the throttle bores. I adjusted the linkage, got them all the way up. Oil consumption is currently 30:1. We'll see if this helps mine too.
 

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Keep us posted ZRT Guy,maybe were onto something here!?
 

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I also adjusted mine last night. I had about 3/16" as well. It makes perfect sense to me... you can see the arm on the oil pump moving long before the throttle assembly does. The oil injection is getting the jump on the throttle bodies, and stays ahead of them the whole way! I was always used to a little "throttle slack" with my other cats and didn't think twice about it. However, after taking off the pipe and checking it out, it's VERY OBVIOUS! Can't wait to test it out... :D

I can't imagine why my dealer didn't see this. I guess he didn't look very hard. :angry: Another story... :lol: )

This should be renamed "all oil-drinking F5 owners read this!"
 

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I also adjusted my throttle to achieve "WOT" and also backed off my oil pump where the line on the pump arm comes up 1/16" short of the WOT mark on the pump. The result, about 1 quart of oil every 130 miles. My next move is to actually figure the ratio. I've since removed the exhaust and power valves and the piston skirts look great and valves showed very little buildup. BTW , I'm using Amsoil. (not the race oil)
 

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98.7 miles
6.755 gallons of gas
18 oz. oil

48:1 oil ratio (improved from the previous 30:1)
14+ miles per gallon

I'm happy with that ratio. Almost 100 miles and the oil light didn't even flash !!

Looks like the throttle adjustment is the trick fix for the F5 oil consumption.

I love this sled !!!
 

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Originally posted by ZRT Guy@Feb 27 2003, 08:47 AM
Looks like the throttle adjustment is the trick fix for the F5 oil consumption.
With the MINOR adjustment that my dealer made...(got me to 30:1 also :blink:

Thanks again everyone...looks like you might have caught the problem. Good job! :D

NOW THIS IS WHAT THE FORUM IS FOR!!!! B) :lol: :D
 

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TTT fo f5 owners..im gonna check mine out tommorow.this sounds like a very sure posibility.thanks for taking time to investigate and reply :p
 

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Discussion Starter #13
The level of performance from this 500cc machine is truely amazing! The throttle response is instant, clutching is accurate, fuel consumption (and now oil consumption) has got to be at the top of the class. The chassis is great and fully adjustable to suit a WIDE varity of riding styles. And with the help of this forum, everyone should have the opportunity of riding a properly calibrated F5. With the amount of snow in my area, all I need to add is a pair of powder pro skis to compliment the high lug sno pro track. Very Satisfied! :D Keep asking questions and sharing thoughts . . . . everyone benefits.
 
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