EGT HELP please

[Lt Rascal]

My Dad picked up an 2000 Yamaha Mountain Max with some mild porting and triple pipes that has a three panel EGT on it. He was told to watch the exhaust temp and not to push it over 1400. The gauge starts flashing and beeping when it reaches 1350. Wile First ride out on it the other day. Going up the trail he had not problems with exhaust temps. But when we go up to fresh snow and hills it was constantly jumping up to 1400. We would sit and let it cool down for a wile then fire it up. Let it warm up for a minute and hit a hill that was 200 yards long and it would be flashing at him.

All this time I am riding with him on my Mountain Max that I have put a digital water temp gauge on. When he was hitting 1400 my sled is only saying 100 degrees. Not even close to the 180 overheat mark.

Neither of us have had any experience with this type of equipment. Can some one help advise us on what temp we need to be watching for. If we can not get but one or two hits on a hill before we are overheating the exhaust. This is not going to be fun.

We are wondering if the jetting is so lean that it is overheating? It has some weird wire tip spark plugs in it so getting a plug reading for jetting is not going to work.

 

[rdr99]

Go up on the main jets. The EGT measures Exhaust Gas Temperature, this is the temperature of the gases leaving the cylinder, has nothing to do with the water temperature. Hotter generally means leaner, however it does depend on where the probe is placed in the pipe. Was this sled ridden at the same elevation as where you are riding it? You can check the piston wash, just remove the spark plug and look through the plug hole with a small light.

 

[byeatts]

My Dad picked up an 2000 Yamaha Mountain Max with some mild porting and triple pipes that has a three panel EGT on it. He was told to watch the exhaust temp and not to push it over 1400. The gauge starts flashing and beeping when it reaches 1350. Wile First ride out on it the other day. Going up the trail he had not problems with exhaust temps. But when we go up to fresh snow and hills it was constantly jumping up to 1400. We would sit and let it cool down for a wile then fire it up. Let it warm up for a minute and hit a hill that was 200 yards long and it would be flashing at him.

All this time I am riding with him on my Mountain Max that I have put a digital water temp gauge on. When he was hitting 1400 my sled is only saying 100 degrees. Not even close to the 180 overheat mark.

Neither of us have had any experience with this type of equipment. Can some one help advise us on what temp we need to be watching for. If we can not get but one or two hits on a hill before we are overheating the exhaust. This is not going to be fun.

We are wondering if the jetting is so lean that it is overheating? It has some weird wire tip spark plugs in it so getting a plug reading for jetting is not going to work.

1350 is pretty high . Go up a size or two on mains. You need to read the plugs and see how lean you are .

 

[pfi572]

How far up the pipe are the probes?
The further away from piston skirt the hotter the reading.

 

[Lt Rascal]

The probes are about 4" from the cylinder.

The original owner did not ride it a lot. When we would ride with him he would always hit a hill once maybe twice and then sit for a wile. Then hit it again. Then sit. We always wondered why. But now we are stating to think that he had it jetted so lean trying to get every HP he could that it was getting hot. So he would let it cool between runs.

 

[byeatts]

The probes are about 4" from the cylinder.

The original owner did not ride it a lot. When we would ride with him he would always hit a hill once maybe twice and then sit for a wile. Then hit it again. Then sit. We always wondered why. But now we are stating to think that he had it jetted so lean trying to get every HP he could that it was getting hot. So he would let it cool between runs.

You need some plug reads to find a baseline for EGT. however anything at 1400 regardless where probe is is downright scary.