Exhaust Temps

[MattM]

Hey guys what is too hot when you are talking Exhaust temperatures? And what would be an easy way to get them lower?

 

[maxwell]

every motor is different and probe positioning and sensor type/manufacturer can all fluctuate.

for me on my sleds usually 1200+ is getting a bit hot

but some sleds run peak at 1300-1450

need to dial your sled in with plug readings and piston wash readings then look at your EGT guage to find out what the correct reading is for youR machine

adding more fuel brings the EGT down but that may not be required

 

[magnet]

what he said.

 

[ridndirty]

every motor is different and probe positioning and sensor type/manufacturer can all fluctuate.

for me on my sleds usually 1200+ is getting a bit hot

but some sleds run peak at 1300-1450

need to dial your sled in with plug readings and piston wash readings then look at your EGT guage to find out what the correct reading is for youR machine

adding more fuel brings the EGT down but that may not be required

Yep, not much else to say.In the old days, 1450 for anything longer than a spike, turned pistons to puddles. But with all the coatings you can get on parts today, they can take it a bit longer.

 

[MattM]

Thanks I just bought this sled this year I'm dying to get it out to the mountains but haven’t been able to yet. The temp seems to peek at 1250ish at about 6300-6500rpm then the temps go down with more rpm/throttle. The sled is an A Cat M7 SP 153 with a 900 Engine tech kit fat azz single pipe light weight can and a timber mountain rear skid. The hood and sides are vented and I just re finished the heat tape. It’s got Racepak 2 gauges that give out the temp readings.

Thanks for the in-put

Matt

 

[Modman]

every motor is different and probe positioning and sensor type/manufacturer can all fluctuate.

for me on my sleds usually 1200+ is getting a bit hot

but some sleds run peak at 1300-1450

need to dial your sled in with plug readings and piston wash readings then look at your EGT guage to find out what the correct reading is for youR machine

adding more fuel brings the EGT down but that may not be required

What he said ^^^^. Mine runs tops to 1350, usually shut it down at 1320-1330, Warning is set at 1300. Each sled is different though.

If you are dropping from 1250 above 6500 rpm, sounds like you are fat on the top end and possibly lean in the midrange. You should confirm this with a plug chop but temps should still be increasing at that RPM, not dropping. Usually mid range temps are around 1000-1150, depending on many factors of course but this is a general guideline. 1250 is a little high for mid-range temps (again, general guideline). You need to plug check all your fuel circuits and see if you are lean or rich to confirm. Also, measure from about the exhaust face of the piston to your probe location, are you running twin probes or only one?

 

[MattM]

Yeah they are twin probes the gauge jumps from probe 1 to #2 every few sec and they are very close the same temp. Like I said I just picked up the sled 2 weeks ago. I really don’t know too much about it. The factory temp warning light has never light up and the second I’m off the throttle the temp drops below 1000 or if I "blip the throttle the temps come right down too. Your thinking this might be a tuning issue? The guy I bought it from really didn't know too much about the set up and I’m trying to learn as much as I can.

Matt

 

[maxwell]

im assuming with all those mods it must have some form of fuel programmer?

should add some fuel to the midrange on your fuel map.

 

[MattM]

yes sorry it does have a boonedocker programer. I have no idea how to use it I have been googleing it but im to afraid of effing something up.

 

[maxwell]

phone engien tech and get some #s from them. who makes the pipe? bikeman?

 

[MattM]

and the distance from the exhaust face to the probe is 3"

 

[MattM]

BMP makes the pipe

 

[Modman]

and the distance from the exhaust face to the probe is 3"

wow that is really close, typically its about 8-12", you are going to have to check the plugs and correlate the temp to the plug colour you are seeing.

Yes it is a tuning issue, you will have to adjust the programmer for each of the fuel circuits.

 

[MattM]

So will the temps read hotter with them being so close? What the best way for a guy to "tune" using the boondocker box? still to scared to start pressing buttons!
hahaha

 

[ryan#1]

Any recommendations on EGT gauges...looking into getting one and wondering if anyone has any advice. It's for an XP with an 860. Looked quickly online..quite a range of prices/products...don't want anything fancy. Thx.

 

[oler1234]

wow that is really close, typically its about 8-12", you are going to have to check the plugs and correlate the temp to the plug colour you are seeing.

Yes it is a tuning issue, you will have to adjust the programmer for each of the fuel circuits.

I heard on the 800r motors you run it 4" from the flange face. We run one in our group like this and seems correct... mayby i am wrong? mayby its just like you say, ever engine is diffrent.

 

[Modman]

I heard on the 800r motors you run it 4" from the flange face. We run one in our group like this and seems correct... mayby i am wrong? mayby its just like you say, ever engine is diffrent.

Flange face on my sled is about 2" from the piston, getting close if you are 4" from the flange (probably close to 6" from exhaust face). You're probably not wrong and so long as its' correlated to plug colour, its just a reference point. Probe palcement seems to mainly depend on style of pipe and where the flame peak occurs, so yes, sled specific. Twin probes in a single "Y" pipe have to be about 2" from the "Y" join at the pipe junction so they are as far out as possible but not so far out so the cylinders do not interfere with one another, single probe in a "Y" they usually say put it right at the "Y" right in front of the pipe junction (this would be 2" farther from the twin probes in a "Y") and for twins/triple pipes its pretty standard on 18-12" out from piston face.

This is where mine are in both sleds and they are bang on correlated to plug colour, slightly darker on the twins which is why I run to about 1350 with it. The triple is max 1320, I usually shut it down about 1280 because it is almost perfect tan at 1250, shows light gray and white at 1300+.

I know a 1085 Polaris that runs at 1350-1380 though, this is a perfect tan on that motor, twin pipes and 10" from the piston face. This sled is running 100% AV gas though so fuel burn will be a little farther down the pipe.

Not sayin' my word is law, that's just my experience from my #'s. Everybody's gotta make their own.

 

[Modman]

Any recommendations on EGT gauges...looking into getting one and wondering if anyone has any advice. It's for an XP with an 860. Looked quickly online..quite a range of prices/products...don't want anything fancy. Thx.

I'm running the koso's on my sleds, really like them

 

[Polarblu]

when im unsure i throw feul at it till it gets hotter(burning in the pipe) then back down to a nice off dark chocolate. Gas is cheaper than pistons.

 

[MattM]

So you guys are looking at the end of the spark plugs to determine the rate/temp of combustion. To see if more fuel is necessary to keep the exhaust temps down? Sorry I’m new to this.