[Huskyracing]

I was loading up to cut trails today and my '16 Kodiak 700 (base model) would start then immediately quit (about 70 degrees out). I hear the pump run, wait several seconds and attempt to start but it won't stay running. Tried several times, waiting about a minute between, no change but once -it ran maybe 12 seconds then quit. Pulled plug and was a little black, tossed in new one, same thing. I have been using rec 90 fuel since I bought it over 4 months ago and the fuel in tank was recently put in, just about 2 weeks ago. I checked fuel pump pressure and it was at 50psi at prime ,dropped to 48 when pump stopped running but went back up to 50 when cranking and the brief moment it ran(about 5 seconds) - didn't run long enough to see if it was changing. Any help would be appreciated.

 

[JimP]

With the problems that I have seen with bad fuel pumps I wonder if checking the fuel pressure would help.

Your problem almost sounds like it is running out of fuel and a fuel pressure problem would cause this.

Here is a PDF on checking it. You will need to build your own pressure gauge along with some kind of a adapter to connect it into the fuel line since it wants you to start the engine and run it while checking the pressure. For a gauge you want a glycerin filled gauge that will take way the pulse input of the fuel pump and just give you a steady reading. I have seen these gauges on Northern Tools web site and they are not that expensive. I've been meaning to get one for trouble shooting on my diesel truck.

 

[Huskyracing]

Thanx...I already used pressure guage and found that when key is turned on and pump powers up ,I get 50 psi. It starts immediately and will only run maybe 5+ seconds. I wait a minute and try starting again and the same scenerio happens. I've done this dozen times with no change.It only runs such a short time but watching the guage it never seemed to drop below 48psi.I think one time it ran a few seconds longer but I tried to lightly touch throttle and it backfired and stalled. I decided to let it sit for a couple hours and pressure was still holding around 42psi. As soon as I turned key on, the pump ran and pressure went back up to 50psi. I pulled the Idle Speed Control off and watched it move in and out ,because according to manual ,you should hear it or if it's removed ,you can see it move when powered up -which it did. I even cleaned the plunger cotact area inside the throttle body but no change.

 

[Huskyracing]

...Still can't figure this one out...pulled out the service manual,checked voltage to injector,injector resistence -even pulled injector/rail and firmly held injector in place -spray pattern was very good and not leaking. I checked TPS setting ,which book says should be at .63-73mv and mine is set at .68. Went a little further and checked tip over sensor,which gives volt readings at approx. 65 degrees more then/ less then and readings all well within range. I even checked spark with a tester that is gapped at .060" and it has a nice ,loud snapping ,blue spark - hell ,even threw in another plug- no change.
I spoke with original owner this morning and he had sent me a picture of dealer invoice back in 2021 ,were it had been serviced with a new fuel pump and relay- I know it still could fail but this has me scratching my head. Kinda wish this model had the onboard guage cluster that shows trouble codes ...

 

[JimP]

This one is going to be interesting to figure out. I was wondering if it may be heat related but after rereading your post I think that heat is out.

This may be one that you'll need to break down and take to a dealer where they can place their diagnostic tool onto it. As the the diagnostic tool, I have looked and it is Yamaha only and I haven't found on on the used market.

 

[JD864]

If you have spark like you verified, then no sensors are shutting it down. All of the safety switches will cut the spark to stop the engine.

It takes 3 things to run. Compression, spark, and fuel. Should be easy to rule out compression. And you ruled out spark. Maybe you have a bad injector? Or something in the fuel circuit? I wouldn’t stop chasing something in the fuel system as the problem. When you put the new plug in, does it get a mist of fuel on it? Or did it stay clean?

 

[Huskyracing]

If you have spark like you verified, then no sensors are shutting it down. All of the safety switches will cut the spark to stop the engine.

It takes 3 things to run. Compression, spark, and fuel. Should be easy to rule out compression. And you ruled out spark. Maybe you have a bad injector? Or something in the fuel circuit? I wouldn’t stop chasing something in the fuel system as the problem. When you put the new plug in, does it get a mist of fuel on it? Or did it stay clean?

I wanted to make sure the engine itself was in good working order so I did a :compression test 138psi (spec 92-142), checked valve clearances -all within spec, leak down test- less then 2% @100psi.While I was checking valve clearances, I checked the decomp. mechanism and spring = OK and checked cam timing marks to flywheel marks at TDC= OK.
Plug (just replaced) shows some sign of rich condition after several attempts at running.

 

[Huskyracing]

I checked the fuel pump relay with a relay tester and indicates it is working...but I may try swapping with the other relay next to it- it is the same relay part number per the parts diagram. Gonna have to do this later, gotta go help cut trails today

 

[Rob-c]

I checked the fuel pump relay with a relay tester and indicates it is working...but I may try swapping with the other relay next to it- it is the same relay part number per the parts diagram. Gonna have to do this later, gotta go help cut trails today

So some thing to check , is see if your getting any resistance in the fuel pump . This would cause it to start but not run. Pump is cool till you run, then builds up resistance.

 

[Coder]

You guys are all ahead of me mechanically in light years! This issue though reminds me of a partially clogged fuel filter, which will allow enough fuel to start and maybe run for a couple of seconds? Then the supply to the injector can’t be met, and the engine quits! Had this issue on more than one vehicles I’ve had in the last 30+ years.

 

[Peruch]

I was loading up to cut trails today and my '16 Kodiak 700 (base model) would start then immediately quit (about 70 degrees out). I hear the pump run, wait several seconds and attempt to start but it won't stay running. Tried several times, waiting about a minute between, no change but once -it ran maybe 12 seconds then quit. Pulled plug and was a little black, tossed in new one, same thing. I have been using rec 90 fuel since I bought it over 4 months ago and the fuel in tank was recently put in, just about 2 weeks ago. I checked fuel pump pressure and it was at 50psi at prime ,dropped to 48 when pump stopped running but went back up to 50 when cranking and the brief moment it ran(about 5 seconds) - didn't run long enough to see if it was changing. Any help would be appreciated.

Check for a clogged air filter. That happened to mine last year. Out on lake Winnipesaukee ice fishing. Had to be towed in. Would barely run. Would start then stall. Mice got in there.

 

[Huskyracing]

...not getting anywhere fast with this . gone thru every wire ,every ground, battery voltage-load test, even checked every relay and sensor, the injector ,the closed throttle butterfly position and everything is within spec., even though most items checked wouldn't relate to issue - mind numbing experience for sure. TPS was at .683 so I tried .692= nothing noticeable, .710 worse. Manual calls for .63-.73, some people said .68 ,so I will leave it at .68 -it's definately not TPS -did the normal voltage test through very slow up and down throttle input and observed no glitches in TPS.
I don't like throwing parts at a problem but since the previous owner had put in a aftermarket Chinese pump assembly ,I am starting to suspect that fuel pressure regulator is pushing a bit too much fuel, manual calls for max 46.1psi and mine is showing steady 50psi - I try to take in account variations in test equipment but maybe just maybe my tester is actually showing the lower side of what it truly is. Well ,I guess a Quantum fuels pressure regulator for $14.95 is in order....

 

[JimP]

You do have a off the wall problem with no easy solution.

I have never seen where too much fuel pressure is a bad thing but then there is always the first time.

Have you opened up the fuel line at the throttle body and then ran the pump and fuel into a can to see what the flow is like? Also where did you place your fuel pressure tester, at the pump as the manual says or further down the line?

Just throwing idea out hoping one will stick

 

[Huskyracing]

You do have a off the wall problem with no easy solution.

I have never seen where too much fuel pressure is a bad thing but then there is always the first time.

Have you opened up the fuel line at the throttle body and then ran the pump and fuel into a can to see what the flow is like? Also where did you place your fuel pressure tester, at the pump as the manual says or further down the line?

Just throwing idea out hoping one will stick

...I have checked the fuel flow several times and flow and quanity are very good- maybe too good...my concern was after watching a few vids and have performed this for a couple of my EFI motorcycles in the past, the fuel shot out at quickly as soon as pump powered up ,more so then I have seen/done, then tapers down to a smooth decent flow. The amounts are always the same but the burst of fuel at first has got me wondering.
I have tested pressures a few times at "both" locations- no difference.
I have pulled the injector ( which is new) and viewed the spray pattern and watched for leakage multiple times with no problems.
I haven't been able to find any info regarding the fuel rail which appears to have a vacuum canister looking thing on the end and what purpose it serves. It has a small phillips head screw on the end but haven't touched it nor do I know if it is an adjustment.

 

[JimP]

The only other thing that I can even remotely think of would be the ECM itself.

Too bad that us common people don't have access to a tool that can test it.

 

[Huskyracing]

The only other thing that I can even remotely think of would be the ECM itself.

Too bad that us common people don't have access to a tool that can test it.

...had fingers crossed this morning, had a friend who has a running 2018 Kodiak 700 and just swapped his ECU (checked part numbers and they are the same) with mine and it's a no go ...even put my ECU in his and mine works...
...got a couple days before my new fuel pressure regulator comes in, in the mean time still searching for explaination of the affect that canister on end of fuel rail ( pic in previous reply) is for and what it controls. I have already checked the pressure sensor per the service manual and it is well within' spec.

 

[Huskyracing]

......FYI,if anyone's interested ...The canister attached to fuel rail is a pressure dampner (pic below)...per a Yamaha EFI SYSTEMS TUTORIAL I found (lots of good info not found in service manual) checked for leaks -NONE, Checked operation when powering up fuel pump "after" bleeding pressure out of line first and it appears to operate as required but because motor only runs for several seconds ,it can not be fully diagnosed.

 

[Huskyracing]

...still no luck!... so I have officially gone through every wire from connector to connector ,even bought a new digital multimeter & leads, followed all the guidelines for troubleshooting components - sensors, switches ,voltage regulator/rectifier, ignition/charging system, fuel pump/regulator/screens/injector, fuel pump pressure at tank and at fuel rail - Installed a fresh new battery with slightly higher cranking amps . Thoroughly cleaned throttle body, check throttle body butterfly opening/TPS setting. New air filter, several new plugs, New TPS and coolant sensor( both were only gremlins that I could find...oh yeah, new coil too - the plug cap cracked after several times removing it and you can't buy just the cap to fit that cavernous hole! Valve leak down test, compression -, checked cam for bad spring/ wear on decomp mechanism -, fresh fuel, fresh oil and filter change, new air filter, checked grounds -,checked for sheared flywheel key/cam timing -. It starts right up but within' seconds shuts off. I have managed to feather throttle a few times to keep it running but it misses and most times backfires. I found someone with the same year /model and swapped the ECU ,no change. Swapped fuel rail and injector- no change. I was at the end of my rope ..tried a new plug- no change, so I decided for the heck of it to check spark again (at night of course)... I may have found something or not ..the spark initially is fast bright and steady but after 4-5 seconds of cranking, the spark is still evident but frequency has slowed down noticeably. I stopped cranking let it sit for 15 seconds or so and the same thing, spark is quick and bright but after several seconds , the spark intervals are slowed down . Don't know if I am onto something but by all means by testing per service manual, everything in ignition and voltage regulator and battery are well within spec. ANY CLUES!?!?

 

[Coder]

...still no luck!... so I have officially gone through every wire from connector to connector ,even bought a new digital multimeter & leads, followed all the guidelines for troubleshooting components - sensors, switches ,voltage regulator/rectifier, ignition/charging system, fuel pump/regulator/screens/injector, fuel pump pressure at tank and at fuel rail - Installed a fresh new battery with slightly higher cranking amps . Thoroughly cleaned throttle body, check throttle body butterfly opening/TPS setting. New air filter, several new plugs, New TPS and coolant sensor( both were only gremlins that I could find...oh yeah, new coil too - the plug cap cracked after several times removing it and you can't buy just the cap to fit that cavernous hole! Valve leak down test, compression -, checked cam for bad spring/ wear on decomp mechanism -, fresh fuel, fresh oil and filter change, new air filter, checked grounds -,checked for sheared flywheel key/cam timing -. It starts right up but within' seconds shuts off. I have managed to feather throttle a few times to keep it running but it misses and most times backfires. I found someone with the same year /model and swapped the ECU ,no change. Swapped fuel rail and injector- no change. I was at the end of my rope ..tried a new plug- no change, so I decided for the heck of it to check spark again (at night of course)... I may have found something or not ..the spark initially is fast bright and steady but after 4-5 seconds of cranking, the spark is still evident but frequency has slowed down noticeably. I stopped cranking let it sit for 15 seconds or so and the same thing, spark is quick and bright but after several seconds , the spark intervals are slowed down . Don't know if I am onto something but by all means by testing per service manual, everything in ignition and voltage regulator and battery are well within spec. ANY CLUES!?!?

Wow , dude I am so sorry hear your troubleshooting misery! Been there, I can relate. I believe it is possible that you have definitely found a clue? Do these bikes hav a CDI? Pulser coils?Id have to check the schematics? The spark strength should be consistent, the frequency though would be determined by the ecu with its reference from the crank position sensor? Yup, you definitely revealed something important! I’ll check with a schematic an get back to you!

 

[Huskyracing]

Wow , dude I am so sorry hear your troubleshooting misery! Been there, I can relate. I believe it is possible that you have definitely found a clue? Do these bikes hav a CDI? Pulser coils?Id have to check the schematics? The spark strength should be consistent, the frequency though would be determined by the ecu with its reference from the crank position sensor? Yup, you definitely revealed something important! I’ll check with a schematic an get back to you!

My multi meter doesn't have the zeroing option (REL mode) but in auto range I just adjust what readings my test leads have from the reading I get when testing a component.... this brought my acceptable range to the very end of their scale...which may be causing the issue. I tried swapping out a known , good working ECU in hopes it would rectify the problem but it didn't( probably a good thing because that ECU is very expensive) ! ... so it makes me question the stator/pulse coil . It seems the stator is relatively expensive and the shops I have used for motorcycle related components (RM Stator and Ricky Stator) don't carry the '16-'18 Kodiak/Grizzly stator but have the older and newer versions!?!?