Possible HOT start issue fix.

[excallibur101]

For my sled personally I've seen zero signs where it's anything other than improper fuel mapping on the start. What works for some will not work for others tho as it seems to be a common trend with the viper.

Common issue amongst many vipers other than turbo sleds from what i read,Maybe a remap should help

 

[Studroes144]

I have a turbo on mine now, just did it over the summer and haven't put much of any run time on it yet but mine still has the same exact starting characteristics as what I described above even now still with the turbo. Maybe that will change once I make some adjustments to the gems controller..but then again maybe it won't change anything without the ecu update

 

[cannondale27]

Yes no word yet and no diag tool to do it yet. The hopefully is just the timing. I know Yamaha can fix this issue. Yellowknife is the one I want to see results with. If his starts they all should.

 

[excallibur101]

A friend of mine who owns a Nitro has encountered that issue as well ,just occassionally not to often as viper,more common on viper as it seems.

 

[wavemaster]

I put a temp gauge on my quad (brute force 750 twin) due to overheating issues with no good way to see what was going on. You can see all of this very clearly if you can keep the gauge on through a full cycle.

Running along at say 180deg. Stop and shut it off, it would climb over 200deg in under a minute (on the quad the sensor was at the thermostat between motor and radiator - flow direction was from motor through thermostat to top of radiator). Fire it back up and 20-30 seconds later it starts dropping back. The over-run on the fan would cool the radiator water down ant it would enter the block cooler.

With a ECU, they can do all kinds of things to fix these heat type issues,
1. Over-run the fan a couple minutes if it is shut down hot,
2. Ignore the temp from the sensor for "x" seconds or minutes after start so the temp can normalize etc.

I think it will be a few fixes that yamaha or cat probably will not divulge. ECU sensor handling, fuel mapping etc.

 

[VIPER85]

I think with running a switch on the radiator fan isn't so much as to cool the radiator and coolant down but more to move some of the trapped hot air in the engine bay around or out of the engine bay so the temp sensors aren't reading hot upon start. I understand running the fan alone wont do much for cooling the actual block. My thought was that lit may help get rid of some of the hot air in the engine bay. I realize the hot start issue has been discussed at length previously on TY, The purpose of this thread is geared toward more running the fan while the sled is off and the pros and cons of doing this. Also if it is worth the time and effort to wire this up.

 

[wavemaster]

.... Also if it is worth the time and effort to wire this up.

I would at least wait until the ECU reflash coming this month or next, over-running the fan may be part of the fix.

 

[excallibur101]

I put a temp gauge on my quad (brute force 750 twin) due to overheating issues with no good way to see what was going on. You can see all of this very clearly if you can keep the gauge on through a full cycle.

Running along at say 180deg. Stop and shut it off, it would climb over 200deg in under a minute (on the quad the sensor was at the thermostat between motor and radiator - flow direction was from motor through thermostat to top of radiator). Fire it back up and 20-30 seconds later it starts dropping back. The over-run on the fan would cool the radiator water down ant it would enter the block cooler.

With a ECU, they can do all kinds of things to fix these heat type issues,
1. Over-run the fan a couple minutes if it is shut down hot,
2. Ignore the temp from the sensor for "x" seconds or minutes after start so the temp can normalize etc.

I think it will be a few fixes that yamaha or cat probably will not divulge. ECU sensor handling, fuel mapping etc.

Perfect example of what I described earlier.one step forward in the right direction.

 

[excallibur101]

Perfect example of what I described earlier.one step forward in the right direction.

Whats up with the engineers who designed this system,they created it they should know how to troubleshoot this issue better than anyone since they designed it,someone knows whats going on they just will not disclose it as of yet.they should be able to provide the best answer to this problem.

 

[RTX]

Whats up with the engineers who designed this system,they created it they should know how to troubleshoot this issue better than anyone since they designed it,someone knows whats going on they just will not disclose it as of yet.they should be able to provide the best answer to this problem.

Not sure what you are looking for.
Its wrong, yamaha has said there is a fix in the works.
Its not really the policy of any major corporation to discuss fixes and engineering on open forums.
Chris Reid has already stated theres an issue in the ecm where numbers are not communicating properly
Im Just trying to be patient and wait for the fix.
It will be here soon enough

 

[subaru2006]

im still curious about all this. for one i know my sled heats up fast, more then likely coolant dilution, so any time i stopped waiting for people and at any stop i shut the sled down soon as the fan kicked on. one time we were cruising down a logging road and you all know how those can be. out of the six sleds 3 600cc 2strokes ran into an over heat issue and i was surprised mine never made it above 190? any ways to make a long story short. knock on wood or whatever, lol i have just over 1100 miles on my sled and not once did i have an issue starting hot or cold. and this past year we were riding in some cold weather due to that very awesome polar vortex. hahaha i think a couple starts soon as i turn on the key the panel read -10.

so my question would be since all these sleds are the same, and the ecu mapping should also be the same, how come this is a hit or miss issue?

subaru2006

 

[excallibur101]

Not sure what you are looking for.
Its wrong, yamaha has said there is a fix in the works.
Its not really the policy of any major corporation to discuss fixes and engineering on open forums.
Chris Reid has already stated theres an issue in the ecm where numbers are not communicating properly
Im Just trying to be patient and wait for the fix.
It will be here soon enough

Personally,that is poor public relations to their loyal customers if that is their excuse.the devil is in the details and they know it.Problem should have been corrected some time ago without delay.I am sorry I don't buy that excuse.Did not take them long to figure they needed a mou gain sled with turbo,did not waste any time there.

 

[wavemaster]

Personally,that is poor public relations to their loyal customers if that is their excuse.the devil is in the details and they know it.Problem should have been corrected some time ago without delay.I am sorry I don't buy that excuse.Did not take them long to figure they needed a mou gain sled with turbo,did not waste any time there.

We can always b***h about the timing or delay and rightly so for the ones with the problem. Arguing about the manufacturers disclosure is just futile. Manufacturers never discuss internal testing or procedures. Many times we will hear about it through back channels but it is very rare that they will share what went on in their testing. Unfortunately, with everyone being so litigious these days, they have to keep it even quieter.

Personally, I think they should have had the ability to flash the ECU's from day one, but that is just me.

 

[excallibur101]

very true.

 

[nate007]

From what I understand, (and I'm not a viper owner), the ecu is a CAT piece, and not the same as the Nytro ecu. This could explain a calibration issue, but if the sled is getting too hot to restart, there's another issue there. Even though the temp rises after shut down, it shouldn't rise enough to over heat. If this is a problem, I'd be looking at ways to increase the cooling ability if the system, and ways to shed the under hood heat from exhaust, etc.
Also, this sled is built in the us, not Japan like other Yamaha models. I'm not certain that it would be built/shipped with 100% antifreeze, but anything is possible..
On my sleds, I've gotten rid of the green antifreeze, and I run BE-Cool's antifreeze, which I use in all my cars. It will cure a marginal hot asked issue with no problems, and does not get diluted. By far the best coolant I've ever used. Pm me if anyone wants some, I carry it at my shop.