'07 Apex running hot / need rear exchanger advice

[Blue Dave]

Hey guys,

Just got back from 16 miles of high speed lake running in low / hard packed snow conditions @ -10 deg. and my temp light came on.

I realize that it is because not enough snow is getting on the heat exchangers, and I am going to add a rear heat exchanger this week.

My question is which one to buy. I have seen several posts describing old design vs. new design Yamaha, Pioneer, comments about stud protection, curved profile, etc.

I want to get the best one for my '07 Apex GT with studs. Thanks in advance for any advice. You guys have taught me a lot so far.

 

[CaptCaper]

If they make the new protector style for your sled that's the way I'd go. The new style I'm talking about I saw on a LTX in a dealers show room. The protectors and cooler were made to go together with a lower profile. My 07 didn't come with anything so I put a older style on but Now I need to fabricate protectors and it will not be as low of profile.

Hey guys,

Just got back from 16 miles of high speed lake running in low / hard packed snow conditions @ -10 deg. and my temp light came on.

I realize that it is because not enough snow is getting on the heat exchangers, and I am going to add a rear heat exchanger this week.

My question is which one to buy. I have seen several posts describing old design vs. new design Yamaha, Pioneer, comments about stud protection, curved profile, etc.

I want to get the best one for my '07 Apex GT with studs. Thanks in advance for any advice. You guys have taught me a lot so far.

 

[BJdaMC]

I just got back from the UP. Riding in -5 F to 5 F had the temperature light come on twice. Had ridden 130 miles prior to the first incident. Both times stopped the sled and looked for issues. Coolant level was fine. It did not appear the heat exchanger was iced over but it is possible the amount of ice under the skid could have been blocking. After about 15 minutes started it up and ran for the next 35 miles. As I came to the next stop I had a backfire and light came on again. Waited for 30 minutes, no problems the remainder 50+ miles.

Realize many talk about adding the rear heat exchanger or changing fluid but has anyone else had other issues being the cause? If not, has anyone had luck with having YAMAHA covering this under warranty?

 

[70superbee]

The new rear heat exchanger is for the 136" sleds, the 121" still use the same rear heat exchanger.You do not need any protecters for that one.
Rich

 

[SharkAttak]

did you check to see if the anti-freeze is a 50/50 mix and all the air is out, i have almost 4,000 mi. on my 06' attak and it never over heats

 

[Blue Dave]

Thanks Capt.

I will look into the "new style" Yamaha rear heat exchanger tomorow. Please clarify if the protectors are integral to the heat exchanger or if they must be purchased separately.

On a related note I checked my coolant concentration with a decent Prestone brand tester(but not a refractometer) at room temperature (70 deg.) and the pointer was off the scale (>70%?).

I plan on diluting it down to 50/50 and adding Red Line Water Wetter when I re-fill after installing the rear heat exchanger.

Anybody know the '07 Apex cooling system capacity so that I can calculate how much Water Wetter to add (1oz per Qt.)

 

[Blue Dave]

Thanks Rich,

You posted while I was still writing my reply. Anybody have p/n for the proper rear heat exchanger for my 121" '07 Apex GT. No protectors needed for my studs?

Shark,

No air, but yes, way too strong of a mixture. Planning on diluting and adding Water Wetter.

 

[Mikey]

Dilute it first 70% is way to thick and will cause it to overheat.... -30/-40F is good enough and will cool the sled better...

 

[Blue Dave]

Mikey,

I just guessed at the concentration, the pointer on my tester was completely off the scale (> -45 deg. F) so it is probably even higher than 70%.

I did ask my dealer about this recently after reading here that so many sleds were delivered with very high ethylene glycol concentrations. He replied that it was an "internet myth". I think not!

I realize that I am not using a refractometer, however a good quality specific gravity type tester should be in the ballpark at room temp. I checked mine by mixing up a "test batch" of 50/50 and my tester was pretty darn close.

 

[fourload]

Put the rear heat exchanger in and don't look back. I had problems when my 06GT was new with overheating and never had another problem after I installed one. I tried the water wetter and correct mixture first but it would still overheat on those low snow logging trails. I also think they run cooler as they pile up the miles and break in more too.

 

[Blue Dave]

Thanks Fourload,

I plan on doing all three, rear heat exchanger, dilute to 50/50, Water Wetter.

Anybody have a p/n for the correct rear heat exchanger and any tricks or good advice on the install?

 

[fourload]

Do a search on this website and you should be able to find it. If not I'm sure Ulmer or one of the site sponsors would know the correct part number.

 

[gitrdun]

Coolant capacity for RX10MSW is 6.76 US quarts, all others are 6.34 US quarts. In December 2007, Ulmer Racing stated the new part number for 121 inch rear heat exchanger was 8-ET-124A0-00-00.

 

[Blue Dave]

Thanks Gitrdun!

How about stud protection? Any tips or tricks for installation?

 

[gitrdun]

I have a 136" which is different in many respects but there is some info right now on page 8 titled "rear heat exchanger" by STILLCRP, where ROCKERDAN shows pictures and I do a rough description of install for an Attak. Parts of that may be helpful. It is a fairly easy install. You should be able to see how far back your track goes to tell if you need stud protection or not.