2007 Apex won't start cold. ( -20 C -5 F)

[sideshowBob]

For extremely cold temps, I added a on/off switch for the fuel pump on my Attak. After a couple cycles of the key to prime the injectors I switch the fuel pump off and start cranking the engine. When the engine has cranked for approx. 15 sec and the starter wont crank any faster I switch the fuel pump back on and keep cranking until the sled is running...this avoids ever flooding the engine. I learned this technique starting fuel injected aircraft in the North in extremely cold temps.
Works for me!

 

[sshewchuk]

There is no fix. 2 2013 Apex’s, 2 Nytros and an 07 Apex all left us stranded on my buddies island yesterday. Guess what, the 1200 doo fires right I’m. I’m done with Yamaha. These things are pieces of garbage. And guess what, the MPI/Rotrex supercharger broke the shaft on the way home. Garbage.

 

[terez]

There is no fix. 2 2013 Apex’s, 2 Nytros and an 07 Apex all left us stranded on my buddies island yesterday. Guess what, the 1200 doo fires right I’m. I’m done with Yamaha. These things are pieces of garbage. And guess what, the MPI/Rotrex supercharger broke the shaft on the way home. Garbage.

1st off....what was the temps?
Are we talkin -40 or something silly like that??
All 4 strokes are gonna give a prob at that extreme.

5 sleds all no start....U may be doing it wrong??
Gotta understand how the 4 stroke sleds are built and operate....its a different ball game than 2 strokes.
If the bumbi flashed right up ??....maybe he knows what he's doin?

My apex has started up lately with -30c deg temps....using the methods I outlined and its bigger 310cca battery.
I had probs with it originally with its oem 220cca batt and me not understanding the beast tho I admit.

 

[earthling]

This when its really cold.
[snip]...
I also went to a bigger battery and an AGM battery.
I went up to a 310cca series 20 agm.
It fits in the battery box with the foam removed.

Sled rolls over much faster regardless of temp and has the balls to do the job when really cold......[snip]

What battery do you have?

 

[terez]

What battery do you have?

Its a Yuasa AGM 310cca battery.
The oem battery in an apex is a lead acid conventional cell 220cca battery which is marginal for the task...and not up to the task when really cold.

If you search me or the topic here I posted a detailed account of the swap including part numbers and some advice.
Having the cca to roll over well is only part of the battle tho...cycling the key a few times 1st and rolling it over right up to when the motor catches ...not just coughs...is essential when its super cold.

 

[earthling]

Its a Yuasa AGM 310cca battery.
The oem battery in an apex is a lead acid conventional cell 220cca battery which is marginal for the task...and not up to the task when really cold.

If you search me or the topic here I posted a detailed account of the swap including part numbers and some advice.
Having the cca to roll over well is only part of the battle tho...cycling the key a few times 1st and rolling it over right up to when the motor catches ...not just coughs...is essential when its super cold.

Thanks I will look up the info. Does anyone know if the aftermarket fuel management kits (dobeck, whatever) are better at fuel management than the original Yamaha system? It seems like half of the cold start problem is just fuel management.

 

[SumpBuster]

Many things already stated, and maybe 10 below when I tried it left outside instead of warm garage....but...I always cycle the fuel pump 2 or 3 times, battery is a Napa gold 2 yrs old, and brought it to Excell for the first it's been anywhere since 07, and he put new plugs in and checked it out. Started pretty good, really. 87 octane too which lights off quicker (less resistance to knock as high octane, since it wants to burn quicker. Plus, it's usually fresher at 2.6 a gallon than 3.10 for 93 octane.Jmo).

 

[Stubbs]

Thanks I will look up the info. Does anyone know if the aftermarket fuel management kits (dobeck, whatever) are better at fuel management than the original Yamaha system? It seems like half of the cold start problem is just fuel management.

My ‘11 Apex with an Ulmer mapped PCV cold starsts better than my Dad’s ‘11 stocker. FWIW

 

[moosekill]

Wow, I was looking at replacing the battery, and I am rather new at this, but it looks like I have to pretty much completely disassemble the sled to replace the battery! Yikes!!

 

[moosekill]

Has anyone looked at the Motobatt MBTX20u? It has the same dimensions as the YTX20H-BS and is supposed to be better built.

 

[Winderallday!]

Wow, I was looking at replacing the battery, and I am rather new at this, but it looks like I have to pretty much completely disassemble the sled to replace the battery! Yikes!!

Wait until you have to change the oil filter!
For just the battery, remove gauge pod, (two bolts) and the airbox, disconnect hoses/sensor going to it, and you have access to the battery. Use a long series ball end allen wrench to access the clamps on the throttle bodies, otherwise take the black pod bracket completely off. Take care when re-installing the airbox boots over the throttle bodies, they can deform/fold over easy, a little film of grease or oil on the boots helps.

 

[moosekill]

It would be really cool if the next time you experienced guys did something like change the oil or change the battery you just took a video doing it, then posted it in the FAQ sections. Watching someone do something like that certainly makes it simpler for us newbies.

Thanks for all the help!

 

[Winderallday!]

It would be really cool if the next time you experienced guys did something like change the oil or change the battery you just took a video doing it, then posted it in the FAQ sections. Watching someone do something like that certainly makes it simpler for us newbies.

Thanks for all the help!

Moosekill: we were all newbies at one point, so you are not alone. Honestly, once you have done it once, it will seem far less of a daunting task next time around. It is fairly straight forward if you have a knack for wrenching and keep track of where things go. Just make sure you are not in a hurry the first time around, this is when things get missed.
It becomes second nature after a while. If you get stuck on something, any of the guys on this forum are glad to help out.
Cheers

 

[TBay Sledhead]

Spark plugs have #’s for a reason, they indicate heat range. The higher the # is, the “cooler” the spark from the plug is. If you have a motor that isn’t a particularly good cold starter, using a spark plug with a cooler heat range # certainly isn’t going to help the situation.

I f you want to know about your plug read this. The temp range has nothing to do with the intensity of the spark. From the NGK web site.
Spark Plug Basics
Spark plugs have been around as long as internal combustion engines have, and are often a misunderstood component. This basic guide is designed to assist the technician, hobbyist or race technician in understanding, using and troubleshooting spark plugs.

Spark plugs are a "window" into the engine, and can be a valuable diagnostic tool. The spark plug displays the condition inside the combustion chambers of the engine. The experienced tuner can use spark plugs to find the root cause of problems, determine air-fuel ratios and increase vehicle performance.

Spark Plug Basics
The primary function of the spark plug is to ignite the air-fuel mixture within the combustion chamber under any operating condition.

Spark plugs must provide a path and a location for electrical energy from the ignition coil to create a spark used to ignite the air-fuel mixture. A sufficient amount of voltage must be supplied by the ignition system to spark across the spark plug gap. This is called “electrical performance.”

The spark plug firing end temperature must be kept low enough to prevent pre-ignition, but high enough to prevent fouling. This is called “thermal performance,” and is determined by the heat range selected.


NGK Spark Plug Heat Rating
The spark plug heat range has no relationship to the electrical energy transferred through the spark plug. The heat range of a spark plug is the range in which the plug works well thermally. The heat rating of each NGK Spark Plug is indicated by a number; lower numbers indicate a hotter type, higher numbers indicate a colder type.

Heat rating and heat flow path of NGK Spark Plugs
Some basic structural factors affecting the heat range of a spark plug are:

• Surface area and/or length of the insulator nose
• Thermal conductivity of the insulator, center electrode, etc.
• Structure of the center electrode such as a copper core, etc.
• Relative position of the insulator tip to the end of the shell (projection)

The major structural difference affecting the heat rating is the length of the insulator nose. A hot-type spark plug has a longer insulator nose. The insulator nose of a hotter spark plug has a longer distance between the firing tip of the insulator, and the point where insulator meets the metal shell. Therefore, the path for the dissipation of heat from the insulator nose to the cylinder head is longer and the firing end stays hotter. The insulator nose of a hotter spark plug also has a greater surface area that is exposed to more of the ignited gases and is easily heated to higher temperatures. A colder spark plug functions in an opposite manner.

The heat range must be carefully selected for proper spark plug thermal performance. If the heat range is not optimal, then serious trouble can be the result. The optimal firing end temperature is approximately 500°C (932°F) to 800°C (1472°F). The two most common causes of spark plug problems are carbon fouling (< 450°C) and overheating (> 800°C).

http://www.youtube.com/watch?feature=player_embedded&v=LbR75wq9nmM

Causes of Carbon Fouling:

• Continuous low-speed driving and/or short trips
• Spark plug heat range too cold
• Air-fuel mixture too rich
• Reduced compression and oil usage due to worn piston rings/cylinder walls
• Over-retarded ignition timing
• Ignition system deterioration

Pre-delivery fouling:
Carbon fouling occurs when the spark plug firing end does not reach the self-cleaning temperature of approximately 450°C (842°F). Carbon deposits will begin to burn off from the insulator nose when the self-cleaning temperature is reached. When the heat range is too cold for the engine speed, the firing end temperature will stay below 450°C and carbon deposits will accumulate on the insulator nose. This is called carbon fouling. When enough carbon accumulates, the spark will travel the path of least resistance over the insulator nose to the metal shell instead of jumping across the gap. This usually results in a misfire and further fouling.

If the selected spark plug heat range is too cold, the spark plug may begin to foul when the engine speed is low or when operating in cold conditions with rich air-fuel mixtures. In some cases, the insulator nose can usually be cleaned by operating the engine at higher speeds in order to reach the self-cleaning temperature. If the spark plug has completely fouled, and the engine will not operate correctly, the spark plug may need to be replaced and the fouling cause identified.

Causes of Overheating

• Spark plug heat range too hot
• Insufficient tightening torque and/or no gasket
• Over-advanced ignition timing
• Fuel octane rating too low (knock is present)
• Excessively lean air-fuel mixture
• Excessive combustion chamber deposits
• Continuous driving under excessively heavy load
• Insufficient engine cooling or lubrication

The most serious result of selecting a heat range that is too hot is overheating. Overheating will cause the electrodes to wear quickly and can lead to pre-ignition. Pre-ignition occurs when the air-fuel mixture is ignited by a hot object/area in the combustion chamber before the timed spark event occurs. When the spark plug firing end (tip) temperature exceeds 800°C, pre-ignition originating from the overheated insulator ceramic can occur. Pre-ignition will dramatically raise the cylinder temperature and pressure and can cause serious and expensive engine damage. When inspecting a spark plug that has experienced overheating or pre-ignition, blistering on the ceramic insulator and/or melted electrodes can sometimes be found.

As a general guideline, among identical spark plug types, the difference in tip temperature from one heat range to the next is approximately 70°C to 100°C.

Tip Temperature and Firing End Appearance

Some factors to consider in selecting the proper heat range spark plug

There are many external influences that can affect the operating temperature of a spark plug. The following is a brief list to consider in avoiding reduced performance and/or expensive engine damage.

• Engine Speed and Load
  • If the engine is to be operated at high RPM, under a heavy load or at high temperatures for long periods, a colder heat range may be needed.
  • Conversely, if the engine is to be operated at low speeds or at low temperatures for long periods, a hotter heat range might be needed to prevent fouling.

• Air-Fuel Mixture
  • Excessively rich air-fuel mixtures can cause the plug tip temperatures to decrease and carbon deposits to accumulate, possibly causing fouling and misfires.
  • Excessively lean air-fuel mixtures can cause the cylinder and plug temperatures to increase, possibly resulting in knock and/or pre-ignition. This may cause damage to the spark plug and/or seriously damage the engine.
  • If an air-fuel ratio meter or gas analyzer is not available, it will be necessary to visually inspect the spark plugs frequently during the tuning process to determine the proper air-fuel mixture.

• Fuel Type/Quality
  • Low quality and/or low octane fuel can cause knock which will elevate cylinder temperatures. The increased cylinder temperature will cause the temperature of the combustion chamber components (spark plug, valves, piston, etc.) to rise, and will lead to pre-ignition if the knock is uncontrolled.
  • When using an ethanol blend fuel with high ethanol content in high-performance applications, a colder heat range may be necessary. The spark timing can be advanced further because ethanol blend fuel has a higher resistance to knock (higher octane). Due to the decreased knock, there will be less audible “warning” from knock before the spark plug overheats and pre-ignites.
  • Some types of fuel additives in lower quality fuels can cause spark plug deposits that can lead to misfires, pre-ignition, etc.

• Ignition Timing
  • Advancing ignition timing by 10° will cause the spark plug tip temperature to increase by approximately 70° to 100°C.
  • A colder heat range spark plug may be necessary if the ignition timing has been advanced to near the knock level. Higher cylinder temperatures near the knock level will bring the spark plug firing end temperature closer to the pre-ignition range.

• Compression Ratio
  • Significantly increasing the static/dynamic compression ratio will increase cylinder pressures and the octane requirement of the engine. Knock may occur more easily. If the engine is operated near the knock level, a colder heat range spark plug may be necessary due to the resulting increased cylinder temperatures.

• Forced Induction (Turbocharging, Supercharging)
  • A colder heat range spark plug may be necessary due to the increased cylinder temperature as boost pressure (manifold pressure) and subsequent cylinder pressure and temperature increase.

• Ambient Air Temperature/Humidity
  • As the air temperature or humidity decreases, the air density increases, requiring a richer air-fuel mixture. If the air-fuel mixture is not properly richened, and the mixture is too lean, higher cylinder pressures/temperatures, knocking, and the subsequent increase in the spark plug tip temperatures can result.
  • As the air temperature or humidity increases, the air density decreases, requiring a leaner air-fuel mixture. If the air-fuel mixture is too rich, decreased performance and/or carbon fouling can result.

• Barometric Pressure/Altitude
  • Air (atmospheric) pressure and cylinder pressure decrease as altitude increases. As a result, spark plug tip temperature will also decrease.
  • Fouling can occur more easily if the air-fuel mixture is not adjusted to compensate for the altitude. Higher altitude = less air = less fuel.

Types of Abnormal Combustion

Pre-ignition

• Pre-ignition occurs when the air-fuel mixture is ignited by a hot object/area in the combustion chamber before the timed spark event occurs.
• When the spark plug firing end (tip) temperature exceeds 800°C, pre-ignition originating from the overheated insulator ceramic can occur.
• It is most often caused by the wrong (too hot) heat range spark plug, and/or over-advanced ignition timing. An improperly installed (insufficient torque) spark plug can also result in pre-ignition due to inadequate heat transfer.
• Pre-ignition will dramatically raise the cylinder temperature and pressure and can melt and hole pistons, burn valves, etc.

Knock

• Occurs when part of the air-fuel mixture in the combustion chamber, away from the spark plug, is spontaneously ignited by the pressure from a flame front originating from the spark plug. The two colliding flame fronts contribute to the “knocking” sound.
• Knock occurs more frequently when using low octane fuel. Low octane fuel has a low resistance to knock (low resistance to ignition).
• Knock is related to ignition timing. (Knock is sometimes referred to as “spark knock.”) Retarding the ignition timing will reduce knock.
• Heavy knock often leads to pre-ignition.
• Heavy knock can cause breakage and/or erosion of combustion chamber components.
• Knock is sometimes referred to as “ping” or “detonation.”

Misfires

A misfire occurs when the spark travels the path of least resistance instead of jumping across the gap. Misfires can be caused by the following:

• Carbon fouling
• Worn or deteriorated ignition system components
• Too large of gap size
• Spark timing excessively advanced or retarded
• Damaged spark plugs (cracked insulator, melted electrodes, etc.)
• Mismatched ignition system components (plug resistance/wire resistance, ignition coils/igniter modules, etc.)
• Insufficient coil primary and/or secondary voltage – voltage required to jump the spark plug gap higher than coil output

 

[RobX-1]

Wow, I was looking at replacing the battery, and I am rather new at this, but it looks like I have to pretty much completely disassemble the sled to replace the battery! Yikes!!

LOL. This is what I would consider "completely disassemble the sled" so getting to the battery is a walk in the park. Yes, it can appear overwhelming considering what you have to take off just to get the battery but as Apexallday has stated, we were all newbies at one time; some of us have just been around since the inception of the RX-1 and have gleamed lots of useful information. Heck, if it wasn't for this site from all the years of reading and searching and then reading some more, I would have never felt confident tearing this far into my new 2018 Apex X-TX.