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Thread: vilter 450xl
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16-12-2007, 08:29 PM #1
vilter 450xl
I am having problems with my 150hp 8 cyl 450xl, its shutting down on high discharge temp, have replaced four of the eight safety heads due to cracking in the discharge valves, we are using the 440 style safety heads, the suction temp runs about 95F yet the house suction temp is around 33, we have two other comps, both are fes 300hp screws and they don't show the high suction temp, is it possible that the unloaders are not working on the vilter?
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16-12-2007, 08:57 PM #2
Re: vilter 450xl
This is one we can really get into.
When you say the suction temp is 33F, I assume you mean the suction pressure, converted to temperature.
The FES screws not seeing the high suction temp is hard to understand. Do you mean that the suction lines temperatures at the machines are that different?
I have seen this occur only when a machine was running but not pumping. If there is no gas flow through the suction to this machine it will run very hot. Vilter puts a limit of 20 minutes or so for a machine to run fully unloaded in some applications.
Please tell us a bit more about your system and compressor.
Is this a new condition, or has it always been a problem? There can be a problem if the cylinder covers are not the right ones. Oil and Gas unloading cylinder covers are different when you look at them closely (do not ask how I found this out!)
I believe you have some Vilter Mechanics around there. This should not be a major issue to resolve.
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16-12-2007, 09:07 PM #3
Re: vilter 450xl
not sure about if this has been a problem in the past, company just purchased the complex, did find several old safety heads lying around so im assumming they have had this problem in the past. the complex is only about 6 years old, and yes the suction temps are that different at the machines. do not know if the cylinder covers are right, what is the difference?
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16-12-2007, 09:26 PM #4
Re: vilter 450xl
The cylinder cover for gas unloading has a small hole drilled through it to the underside of the head. It is easy to miss, or ignore the lack of. If it has been replaced with a oil unloading head the compressor will not load.
Please keep in mind my expertise is with the 440, not the 450. Some parts are different.
Do you have the manual for the 450?
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16-12-2007, 09:46 PM #5
Re: vilter 450xl
I will check out the heads, thanks. yes i do have he manual for it
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16-12-2007, 09:53 PM #6
Re: vilter 450xl
If the machine is not apart now I can suggest some other checks to determine if the loaders are working properly.
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16-12-2007, 09:58 PM #7
Re: vilter 450xl
the machine is apart, but we are putting it back together next week with the rest of the safety heads changed, but i will definently love some suggestions on how to check the loaders
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16-12-2007, 10:32 PM #8
Re: vilter 450xl
It is not very complicated.
I will assume that at least two of the cylinders are loaded at all times. A few machines were made that would unload them all.
After you start the machine, put an clamp on Ampmeter on one of the motor leads.
Operate the unloader controls and watch for a change in curret draw. You can also listen to the change in sound if the engine room is not too loud.
If you had bad valves it is possible that the machine could not pump enough to draw gas through the machine. Bad valves would also raise the discharge temp.
I am assuming that you have the diaphragm type valves. In any case you need to lap (or surface grind) the bottom of the safety head and the top of the cylinder if there is any question of its condition.
The suction valve surface of the cylinder can be lapped as well, but requires a little trickery. It is not as critical as the discharge side.
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16-12-2007, 10:39 PM #9
Re: vilter 450xl
thanks i will try that and let you know what i find out
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17-12-2007, 01:36 PM #10
Re: vilter 450xl
Another thing to check is the free length of the head springs. If they are below tolerance (over compressed) the entire valve assembly could be lifting allowing bypass between the liner and the valve plate. If this compressor has been running hot for a long time the springs may need replacing. Paul
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17-12-2007, 02:44 PM #11
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20-12-2007, 02:27 PM #12
Re: vilter 450xl
Vilters also have internal relief valves that vent from the discharge side back to the crankcase. It may be loose, blown, etc. Check that since you have it apart.
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21-12-2007, 03:17 AM #13
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21-12-2007, 12:41 PM #14
Re: vilter 450xl
A 450XL would probably have disk or valve plates same as suction valves (but smaller in diameter).Another check could also be good water flow through heads.should be able to hold your hand on each head.Good oil pressure to load heads,say 40psi.Proper head gasket on each head,as if cylinder has no unloaders or unload piston discharge gas will recirculate back into suction through unload piston open hole . Does compressor have bypass solonoid between suction+discharge?. If so is it recirculating gas back into suction?.Maybe after assy if you dont find anything obvious with anyones suggestions a valve test could be carried out .A simple test before you put side cover on sump is pump up discharge side of comp with air / nitrogen to see if it does"nt blast or leak into sump area to quickly, if it does obviously see where from.
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21-12-2007, 05:45 PM #15
Re: vilter 450xl
It's interesting that you are using 440 heads on the 450, I thought about doing the same on our 4516XL. I had a few of the springs in a safety yoke start spinning and drill their way into the yoke. Three of them next to each other, net result was a broken discharge valve plate which led to spinning a rod bearing and destroying the crank. I know this is off the topic, but since the company just purchased the building, you don't really know what was done in the past or why. Maybe the former owner had safety yoke problems that caused similar damage like ours. This may be the reason why the safety heads are not 450's. We had to replace many parts on ours because it got really hot before the oil temp cut out shut it down.
Last edited by L1GHTYR; 21-12-2007 at 05:50 PM.
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04-01-2008, 03:10 AM #16
Re: vilter 450xl
well we seemed to fix the problem, only now we are getting high discharge temps, whats your thoughts?
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04-01-2008, 03:39 AM #17
Re: vilter 450xl
This from your first post...
Originally Posted by Joshieboy
Originally Posted by Joshieboy
High discharge temperatures are usually the result of broken discharge valves, leaking internal relief valves, abnormally high suction superheat, or too high of a compression ratio.
The maximum compression ratio for a Vilter recip. is 8:1 (on ammonia). If you are operating higher than this your suction pressure is too low or your discharge pressure is too high.
Check the easy stuff first before you begin to replace parts.If all else fails, ask for help.
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04-01-2008, 06:02 PM #18
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04-01-2008, 08:28 PM #19
Re: vilter 450xl
Hi Grizzly,
Sure, air will increase the discharge pressure, which in turn raises the compression ratio and at the same time causes the discharge temperature to increase.
The increase in temperature due to the air would require a LOT of air to be present.
Abnormally high discharge temperature usually result from broken discharge valves, high suction superheat, or leaky internal relief valves.If all else fails, ask for help.
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04-01-2008, 10:58 PM #20
Re: vilter 450xl
well before we were having high suction temps, but thats better now, what we are getting is about 33psi on the suction side, 35-36 degrees, suction side. at 80psi discharge the temp stays about 220, if we try to get it up to the 110 were we like to run it, the temp shoots up to 260 or higher and the oil temp runs about 140-142. I hope that clears things up
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04-01-2008, 11:48 PM #21
Re: vilter 450xl
33 psig is about 20°F, so that would mean you have about 15-16°F of suction superheat If I am reading you data correctly. That's not too bad.
80 psig discharge isn't too bad either as long as you have sufficient pressure to push liquid to the expansion devices. However, if you are trying to run full cooling loads you might find the TXV's (or whatever you are using) may not be capable of providing sufficient liquid to the evaporators.
220-260°F is not too high under normal conditions, but 260°F seems high with only 110 psig discharge pressure.
Are the compressors fully loaded? At part load the discharge temperature may creep up a bit.
For the oil temperature of 140-142°F, this is high for the operating conditions you are running. Either the oil cooler is not getting enough water or the oil cooler may be partially plugged up with dirt.If all else fails, ask for help.
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09-01-2008, 09:31 PM #22
Re: vilter 450xl
the system used to run at 110 psi discharge at 180-190 F, but it has always seemed to have high oil temps, we have cleaned out the oil heat-exchanger and were pushing plenty of water through it, i'm just wondering could the water flow be to fast and not absorbing that heat?
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09-01-2008, 10:56 PM #23
Re: vilter 450xl
It could be the water-cooled jackets have a lot of scale which causes the water flow to slow down. That would increase the oil temperature if the water supply is in series with the oil cooler and jackets. The water flow is typically though the oil cooler first and then the heads. If the heads scale up, the water flow could be reduced.
If all else fails, ask for help.
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17-02-2008, 06:26 PM #24
Re: vilter 450xl
I've read this whole post and something seams wrong, which you know. The facility has multiple compressors on a common suction. All the conditions would then dictate to be some what the same. Yet, the compressor is either over compressing or the dischage gas is bypassing into the suction and recompressing.
I ran this system on a Ph chart to see what the discharge temp range thearetically would be. I came up with no less than 170f at 50 psia and 124 psia.
I dont think there's much difference between the 440 and 450XL machines (except that they took off all the sharp edges inside, my fingers thank them). Everyone else came up with great suggestions. I would look at two things. Compression and Inefficiency creates high dischage temps. I would look for a true Crank Case suction presure vs Discharge Preasure and make sure the gauges calibrated and are not before (suction) and after (discharge) of any valves. I think these machines are suction unloading so this really would only increase the cyclinder temp not the dischage temp. I would also shut down the machine and isolate the suction to see if the d valves hold.
Also another trick I would do is get a IR temp meter, turn off the water to the heads (temporally) and check the top and sides of the cyclinders any cyclinder that is loaded will be doing work thus warmer head, any cyclinder with bad discharge valves will be really hot, any suction valves bad will be warmer on the casing wall, any unloaded cyclinder will be the same as the bad suction valve. Play with the unloaders and watch them work with temperature. Get to know your machines, love your machines.
The reason I would check the pressures is because I once had a lunch bag located before the isolation valve on the suction side of a machine causing a pressure drop into the crankcase. I failed to notice the issue on start up and had high dischage temp issues. What a pain to repair. Say thanks to the welders...
Rick
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17-02-2008, 08:37 PM #25
Re: vilter 450xl
It's impossible to make anything foolproof because fools are so ingenious...
Don't ever underestimate the power of stupid people when they are in large groups.
Please, don't teach me how to be stupid....
No job is as important as to jeopardize the safety of you or those that you work with.
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17-02-2008, 08:54 PM #26
Re: vilter 450xl
Did my IR temp probe pass you by Josip? Really, check the head temps with the water cooling off. You can see what cyclinder is loaded and what one isn't. Mark your heads with the cyclinder number and compare it to a simular machine on your common suction. You can't get around physics. The heat of compression is very constant on machines check each head. You will see two pistons per head with an IR temp meter. Also check you seal temps often the will tell you alot. Trending temps on a by- annual basis will help with rebuild times.
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17-02-2008, 09:41 PM #27
Re: vilter 450xl
Hi, Core4 Guy
.... no, I us IR instruments too.....but, for broken discharge valves no need to have IR temperature meter...you can feel that by hand even with cooling water running....it is sometimes a problem to check suction valves when cylinders are within case (not extended out) but then we have some other marks showing problems with suction valves...compressor works continuously....to low compressor capacity...excessive suction pressure...abnormal noise from compressor...
....also we can check the state (of two in parallel working compressors) sometimes only by comparing power consumption...
....my comment was regarding good installation of start up suction filter bag...
...generally I agree with your troubleshooting methods
Best regards, Josip
It's impossible to make anything foolproof because fools are so ingenious...
Don't ever underestimate the power of stupid people when they are in large groups.
Please, don't teach me how to be stupid....
No job is as important as to jeopardize the safety of you or those that you work with.
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17-02-2008, 10:12 PM #28
Re: vilter 450xl
Josip, I would say this to my boys. Then why do you have what seems to be an answerable problem? High discharge superheat.
I am new to this and please don't think I am being anything but inquisitive. I love what I do and don't mind in the least, being wrong.
Somethings have answers, but they must be broken down to the simplist form. Is one cyclinder creating a higher compression ration than another. Does one cyclinder have a higher incoming superheat than another. Do they all? You don't have to have a bad discharge valve to have a higher discharge temperatures. But, you do have to have a higher compression ratio (system problem or a compressor problem) or an inefficient cyclinder (recompression or suction leakage).
We are alot alike, we are the same age, we have the same duties, and we care enough to learn and ask questions.
I don't have the answer with the exception that if there is a difference between the original 450 suction and discharge valve volumns as compared to the 440 valve volumns. If the 440 Valve plate can't accomadate the higher volumns of the 450 stroke it will create a higher discharge temp... Thus a higher internal compression ratio, thus higher DSH.
Would you like me to call Wayne Weber who used to head of engineering at Vilter. I can guarentee there is a solution to the problem.
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17-02-2008, 10:32 PM #29
Re: vilter 450xl
Second day on the forum, already smarter than the Mods.
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17-02-2008, 10:40 PM #30
Re: vilter 450xl
Originally Posted by Core4 Guy
Josip was not the one who started this thread, he is only trying to help the original poster. Who, unfortunately has not been visiting his thread he started.
If we had better information and a line of communication with the original poster we can get through this, no problem.
BTW, I used to work for Wayne and I'm sure he has better things to do than troubleshoot fickle compressors.If all else fails, ask for help.
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17-02-2008, 10:41 PM #31
Re: vilter 450xl
Originally Posted by NH3LVR
Now play nice!If all else fails, ask for help.
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17-02-2008, 10:51 PM #32
Re: vilter 450xl
NH3LVR,
As I said I am new to the site, I am young, and I love what I do and do what I love. I just thought I'd offer a different view.
I really came to this site to see what other people think about energy usage. I hope you know I'm not as smart as what you call the Mods. I'm from CA and I'm young as you can tell. Some times I think before I type. I just get excited by people that care... (I can see that I'm a short timer here!)
US Iceman,
Do you also know Fred Heidrick?
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17-02-2008, 11:00 PM #33
Re: vilter 450xl
Yep, he and I worked on the Vilter software programs for many years. We are suposed to get together for dinner in the next few days.
How did you come to know Fred?If all else fails, ask for help.
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17-02-2008, 11:14 PM #34
Re: vilter 450xl
Tell John & Fred I said hi... We are partners together forever in enGEN Systems (know matter how long it takes). An organic rankin cycle system. A heat driven refrigeration system... Waste heat can solve processors energy problems.
Tell Fred to get off the phone and is he still "drinking" Spiced Rum?
You will find out all about me from Fred. I really love the "stinky" stuff and have grown up in it.
I also have r-22 systems running far more efficiently than NH3 system. I look for cooling industries that need energy efficiency and right now it's data centers...Have you ever seen a suction pressures higher than discharge pressures, in a running system? Ammonia or Halocarbons, Thermosyphon is the answer.
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17-02-2008, 11:23 PM #35
Re: vilter 450xl
Originally Posted by Core4 Guy
Originally Posted by Core4 GuyIf all else fails, ask for help.
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17-02-2008, 11:26 PM #36
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17-02-2008, 11:37 PM #37
Re: vilter 450xl
No problem. I hope I have better luck with that comment than the one I made about giving away secrets.
If all else fails, ask for help.
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17-02-2008, 11:45 PM #38
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17-02-2008, 11:55 PM #39
Re: vilter 450xl
Secrets, Lets go back to the original post 450XL.. I don't care what the systems doing as long as the two compressors are doing different things. Discharge superheat is physics and inefficiency. There must be a difference between the two. If I have to say, "period". One machine can't produce a massively different discharge than another unless there is a problem in that machine. The only way to figure it out is to "figure it OUT."
As far as secrets go I really don't like giving them away, "ones we can sell" but be serious.
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18-02-2008, 12:10 AM #40
Re: vilter 450xl
Hi, Core4 Guy
I must admit I do not know Vilter piston compressors at all...but, compressor is compressor and pistons are pistons 4, 6, 8, 12 or 16 within one case...and refrigeration process is the same.....speaking about high discharge temp....could be a lot of reasons....some of them are here...
-compressor safety valve leaky-or open bypass valve
-discharge valve/s leaky or defective
-filter in liquid line is clogged
-excessive load on plant
-expansion valve produces high SH
-expansion valve sensor misplaced
-condenser needs cleaning
-refrigerant vapour in liquid line
-refrigerant charge insufficient
-insufficient coolant/air to condenser
-temp of coolant/air to high
-expansion valve lost charge
-restricted supply of refrigerant
-external pressure equalization on expansion valve closed
-water valve closed
-expansion valve partially clogged-wax, ice, dirty..
-non condensable gases in condenser
--maybe I forget something....
Originally Posted by Core4 Guy
Best regards, Josip
It's impossible to make anything foolproof because fools are so ingenious...
Don't ever underestimate the power of stupid people when they are in large groups.
Please, don't teach me how to be stupid....
No job is as important as to jeopardize the safety of you or those that you work with.
-
18-02-2008, 12:13 AM #41
Re: vilter 450xl
It's impossible to make anything foolproof because fools are so ingenious...
Don't ever underestimate the power of stupid people when they are in large groups.
Please, don't teach me how to be stupid....
No job is as important as to jeopardize the safety of you or those that you work with.
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18-02-2008, 12:28 AM #42
Re: vilter 450xl
Josip,
First off, if you say you have two machine operating the same load suction and discharge (basically next two each other and water cooled), eliminate the system problems and concentrait on the machine issues... this is getting good. The water cooling is not designed to change discharge temp it's only designed to change head (for oil breakdown) and oil temp. The discharge temp issue of a individual machine is not a function of anything but the machine on a common system. If you trend everything (yes the walls of the compressor exterior cyclinder) you will see something.
This all got way out of line and I'm sorry of ego's were bruised. I love this "Forumn" after one day but I can see that I might have to watch what I say and how I say it. I really only wanted to learn how much money places Croatia were paying for energy, water, and sewer... Your guy's can really ball, go Warriors!
Rick
Rick
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18-02-2008, 01:12 AM #43
Re: vilter 450xl
I can think of a bunch of people on this forum that could troubleshoot this problem in short order. It is a shame that the original poster seems absent.
I used to love working on these sort of problems. In and out. If it was not for these kind of problems the boss would have sent the younger (and cheaper) guy.
But now I drive a desk. But it is interesting dealing with the refrigeration contractor who services our plant. When they throw out terms like "Superheat" and "Pressure Drop" I fail to fall to the floor and worship at their altar.
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18-02-2008, 01:37 AM #44
Re: vilter 450xl
Originally Posted by Core4 Guy
It's OK to renew the thread with new comments, but it's not really necessary to address the moderators or other RE members as uninformed.
After you are here for a while you will begin to see how difficult it can be for others to understand an American sense of humor versus someone else's.
Most of the members here are patient enough to translate the posts into their native language and sometimes the "full effect" does not come across. Likewise enthusiasm is hard to present in a written post.
This is not about bruised egos, it's about getting along with others who may interpret the messages in different ways.
Originally Posted by Core4 Guy
In Josips reply he touched on an area we frequently have problems with. People want answers with very little data for us to analyze.
Here's an example: My discharge pressure is too high, what can be the problem?
We see this a lot. Then when members or moderators (mods for short) try asking for information and data the poster sometimes stop replying or loose interest.
This thread is an excellent example. You can't analyze anything with only several pieces of information. More input is always nice to have though and opinions are welcome.If all else fails, ask for help.
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18-02-2008, 01:43 AM #45
Re: vilter 450xl
Originally Posted by NH3LVR
Oh I bet they love you! People like to throw around technical terms like a bull passes **** (you know)
It's more fun waiting for them to overload their backsides and then ask them a subtle question. It does not take too long to sort out the good ones from the less desirable ones.If all else fails, ask for help.
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18-02-2008, 01:50 AM #46
Re: vilter 450xl
Good luck guys....
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29-12-2008, 02:14 AM #47
Re: vilter 450xl
I have read this entire epic of a disfunctional 458XL. try this USE PARTS FOR A 458XL ON A 458XL. replace the valve plates and springs, check the safety springs for wear or deformation, and replace the safety relief valve, clean the suction strainers and confirm proper water flow through the oil cooler and the heads. make sure all the parts are clean and assemble the unit by the book. after startup make sure all banks are loaded. also replace the discharge thermometer and pressure gauges. your issue should be resolved if factory rebuild procedures are followed step by step.
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16-01-2009, 11:19 PM #48
Re: vilter 450xl
I can remember coming into the engine room one morning anf finding my Vilter 350L (R-22) looking like a flame thrower was parked in front of it. The blue paint was more like a dark brown. The unit ran unloaded after a low press cut out failure. We added a hi temp manual reset cut out and placed the bulb on the discharge line. and gave the unit a freash coat of Vilter Blue.........
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09-06-2009, 12:54 AM #49
Re: vilter 450xl
Hi people, sorry I haven't been checking my thread but I had to throw my hands in the air and call in the pro's to fix it as I am new to this. It turns out the problem was a improper head gasket allowing discharge gas into the crankcase. Once again sorry for not checking back waaay sooner all your help was appreciated.
Joshieboy
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09-06-2009, 01:28 AM #50
Re: vilter 450xl
How did you get an improper head gasket?
Any hot gas recirculation will cause high discharge temperatures. It is almost the same problem as bad discharge valves. The gas gets compressed once, leaks back into the cylinder, gets compressed again and the temperature goes way up.If all else fails, ask for help.
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