98 arctic cat zr600 efi starting/running issues - Snowmobile Forum: Your #1 Snowmobile Forum

djhammy · 01-13-2013, 04:05 PM

hi everyone, im new to posting threads and owning a sled, could use some help here.I have a 98 zr600 efi le with 5k miles, I know it will need some work soon,it started on 2nd pull & ran ok, had a hesitation (sometimes backfired) at half throttle, I had to play with throttle a bit and punch it and it would take off like it should, I got out on the trails, same issue, it didn't like goin 15-20mph unless i'd punch the throttle here and there, seemed to not take off as fast after about 50mph, got it home and I cleaned out a mouse nest in the air box and dug deeper to pull the reeds out, they were oily so I wiped them up. read on here about the kill switch issues, messed with that a bit and ended up leavin it alone, so where im at now is when I try to start the sled, it like starts on a very high rev engaging track, very scary, thank god for studs and concret it just slid, currently starts with hi rev and kills. neighbors getting annoyed from noise...lol. anybody got ideas that an inexperienced sled owner can check out? I am mechanically inclined, but sleds are new to me, thanks ahead of time.

djhammy · 01-13-2013, 07:56 PM

so I rechecked over a few things I previously removed, noticed an o ring missing from what I think is tps sensor, if air was coming through I guess that could have caused an issue in the high idle. in doing so I noticed that there is play in how the tps sensor mounts up (where the two bolts go, there not just circle, its longated) so im wondering if it should be tightened down with a bit of tension, if it has anything to do with idle, slightly opening it up letting a bit of air through?

smokingcrater · 01-13-2013, 08:18 PM

do a compression check... Quite a few of the symptoms you mention are common with the top end going out and having low compression. its cheap and easy if you catch it before it lets go, it gets really expensive it the engine blows.

Josh Kidner · 01-13-2013, 09:23 PM

Quote:

Originally Posted by smokingcrater

do a compression check... Quite a few of the symptoms you mention are common with the top end going out and having low compression. its cheap and easy if you catch it before it lets go, it gets really expensive it the engine blows.

Before it blows your looking at all new gaskets/ new piston rings. After you could be replacing cylinders, pistons, and heads. Ouch!

djhammy · 01-13-2013, 09:42 PM

Hey thanks for replying, Seein as it has 5k allready your prob right but it was starting nornal before that's why I figured it had to be somthing I did while cleaning it out, so are you saying before I had the issue with high idle and dieing right away it might be topend?

smokingcrater · 01-13-2013, 10:11 PM

Quote:

Originally Posted by djhammy

Hey thanks for replying, Seein as it has 5k allready your prob right but it was starting nornal before that's why I figured it had to be somthing I did while cleaning it out, so are you saying before I had the issue with high idle and dieing right away it might be topend?

absolutely. shortly before my top end went out, it wouldn't idle well, and when it did, it was fast. I was a pain to start, and power was way down. it would also backfire at lower RPM's, once you got it up it would seem somewhat normal.

50 miles later it completely let loose. Destroyed 1 cylinder entirely, had to pull the engine entirely out to get the remains of all the metal. The head was really beat up and I needed to do lots of smoothing with a dremel.

djhammy · 01-13-2013, 10:48 PM

ouch, well good looking out, so what should I be buying in parts to do the top end?

smokingcrater · 01-13-2013, 11:57 PM

There are kits out that contain everything, but in general, you need pistons, rings, c clips, base gasket, head o-rings, bolt o-rings, and exhaust gaskets. Cost is less than you think, you can find kits probably starting around $200. oem vs aftermarket pistons is a holy war, personally I like wiseco pistons as long as you ALWAYS let the sled warm up before getting on the throttle.

general recommendation for AC engines is to refresh the top end every 3k miles. Might make it more, way more, but at some point you will have a failure.

djhammy · 01-14-2013, 12:06 AM

there like 240 on ebay, ill do some searching elsewhere tho, you got any ideas on if I decide to go with a larger bore kit, how much a machine charges? and whatever else im missing in additional cost?

smokingcrater · 01-14-2013, 08:20 AM

Quote:

Originally Posted by djhammy

there like 240 on ebay, ill do some searching elsewhere tho, you got any ideas on if I decide to go with a larger bore kit, how much a machine charges? and whatever else im missing in additional cost?

If you do a larger bore, the cost goes up dramatically. (having cylinders bored/sleeved/replated) Easily double or triple of just a top end refresh. I personally wouldn't unless you were at the point you needed to do cylinder work, but others might disagree.

djhammy · 01-14-2013, 09:22 AM

k thanks for the advice, my cat thanks you for me not blowing it up, lol.

**kccats** · 01-14-2013, 05:58 PM

Do a compression test at wide open throtle! I have a big bore kit for you! Also do a fuel presure test!

djhammy · 01-14-2013, 08:26 PM

I don't have the means to do a pressure test. I think i'll stick to factory bore, but thanks....man this is the worst time of the year to have a downed cat....

**kccats** · 01-14-2013, 09:00 PM

The presure test is VERY simple! All you need is a foot of 1/4" fuel hose, a 1/4" hose T, and a 0-60 gauge and a hose conection! You should be at 36 psi!

djhammy · 01-14-2013, 09:07 PM

Gotta hit up ace hardware tomaro, the 1/4 T has to thread into spark plug whole right?, and how do I do this? With an air compresser?

djhammy · 01-14-2013, 11:14 PM

ok, I know how its done now, I wouldnt need a T just the hose, fitting for spark threads and gage, and I just pull it 4-5 times. aint I sapposed to see it reach over 100psi per cylinder? anybody know offhand the thread size I need for spark plug hole?

**RJ Gleason** · 01-15-2013, 05:29 AM

No, he's talking about doing the fuel pressure test.
To test compression, you just need a screw in gauge and you want to see at least 115 or better.

**kccats** · 01-15-2013, 06:36 AM

You would need a compression tester! Then the T and hose for the fuel presure! Take the presure side off (clutch side) and put a small piece of hose back on the rail. Then the T between the old hose and new. Then the rest of the hose in the center to the gauge. You will need a hose to female thread addapter (1/8 or 1/4"female iron pipe) which ever the gauge is!

djhammy · 01-15-2013, 08:15 AM

Ok, ya we were on two different pages, but I get the general idea now, thanks guys! I just needed to know what thread size I need for spark plug threading to do a compression test on heads.

**RJ Gleason** · 01-15-2013, 03:26 PM

Compression test gauges will have the correct size end to thread into the head.