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Discussion Starter #1
I want to turn up the fuel on my Diesel. Everything is stock right now except for the EGT sensor I installed in the exhaust manifold.
I baselined the temps when pushing the ATV up hill at full throttle and 900 F is the top end.

I went to loosen the but and turn the screw but it looks like the flat of the nut is right against the timing belt cover.

Is it possible to get that nut loose with removing the plastics and the timing belt cover?

I drilled a hole in the fender that would allow me to get a long screwdriver on the screw and I can get a wrench on the nut but it looks like it wont turn without removing the timing belt cover.
 

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Try removing the front plastics first, then you can get directly at it. Set nut counterclockwise to loosen, screw, clockwise for more fuel. My only warning, if yo do not do a turbocharger and turn in the screw all the way, EGT's can get quite high if you work it hard in Hi range.
 

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I did the same as you Skispcs but stopped when trying to adjust due to a whole lot of thread locker on there. Was hoping by making an access hole that I could get it done easy. I honestly haven't tried anymore as the screwdriver started to round off the flat head slot. Hitting it with head is the answer but like you, I don't want to remove all the plastics & I can't get a good answer if I can just remove the screw all the way with the lock nut in place to loosen/heat it off the machine. Don't want to mess anything up.
 

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I suspect that Lombardini/ Kohler added the thread locker to the newer models to keep the EPA happy. Also the older ones had the rev limiter spring for 4300 rpm and the newer ones are only 3800 rpm. 4X4hans in Namibia did a turbocharger on his 2014 and mentioned that the screw was threadlocked. He visited Maine and drove my 2008 with the turbocharger, 4300rev limiter and fuel screw maxed. He was quite surprised by the faster acceleration and higher top speed. My diesel had no problem keeping up with my 700 TRV on a 200 mile trail ride, 50 mph top speed for the last 50 miles! Before I did the turbo, I would see the EGT's climbing to 1300F, running up hill ,wot with 2 people! Anyone ever thinking about turbocharging one, absolutely will need to max out the fuel screw. Perhaps a small soldering iron to melt thread locker?
 

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Discussion Starter #8
I finally had some time so I pulled the front plastic most of the way off to get to the screw.
I ended up having to remove the three allen screws in the timing belt cover to pull it a bit out of the way in order to get a socket on the but and loosen it without rounding it off.
 

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Skispcs, I heard it's a bitch on the newer ones, but well worth it. These motors are way under fueled, probably thanks to the EPA! Imagine how many polar bears will suffer, if you turn in the screw! haha. I heard diesel smoke kills the Corona virus, though.
 

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Discussion Starter #10
Anyone that tries in the future, remove the threadlocking/anti tamper stuff first. Carb cleaner seemed to soften it.
Buggered up the threads on my screw trying to move it with that stuff still on.

Anyhow, I turned the screw in 1.5 turns and acceleration seems to be better, top end did not have much change. I assume this is limited by the RPM limiter.

I have an EGT sensor in the exhaust manifold.
When stock it typically maxed out at about 950 to 980F when going full throttle up a long incline.

Now with the fuel screw turned in 1.5 turns, I am hitting 1050 to 1100F up the same incline.

How hot is too hot? What temperatures are good and what should I not exceed?
 

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1100F should not be too high. I screwed mine way in before the turbocharger install, I would see it heading to 1300F with 2 people going up a steep grade at wot. Once I turbocharged it, EGT's dropped way down, and acceleration went way up. It is a good idea to have a pyrometer unless you turbocharge and turn the screw to the max. As far as top speed, the older ones like mine came with the 4300 rpm governor springs, mine is an 08. 4x4 hans has a 2014 that came with the 3800 rev limit spring, as I recall. Mine tops out at 50 mph, even with the turbo. It gets to 35 mph as quickly as my "clutched" 700 TRV, even 40 comes up pretty quickly, but 50 takes a long while. From my experience, though the Diesel is tough as a bag of hammers! I have used mine as a log skidder and 4x4hans' daughter ran it WOT , with 2 people for about 50 miles, to no ill effect. I think you can safely turn the screw in more, just ease off when you see 1250F..
 
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