HARD START

Cire74

New Member
Joined
Mar 30, 2021
Messages
17
Location
Pottsgeove, PA
Crazy, just had the no start problem @ 30° here in south eastern PA. Pulled the EFI fuse, cranked it over (it actually started for about 10 sec) put fuse in and she tried real hard, repeated the process a second time and presto, fired right up. I hope this isn't going to be a new NORM!
Thanks a ton to everyone for this help. I was dead set on weak battery until this!
 

Tenman

Well-Known Member
Joined
Dec 7, 2013
Messages
2,102
Location
Natchez Ms USA
Well I just did an experiment with unplugging my 02 sensors for science. Gen 1 flashed with PCV. headers and yosh rs4. 70k miles. It back fired and was hard to start right off the bat. Then it idled down and got right. I left it running a few minutes and it died. It never does that. It fired bak up fine. As soon as I got on the road I could tell something was off. Erratic throttle. I set the cruz at 50 and it was constantly hunting. I see other well know members say that it did them some good. Maybe I'm missing something. IDK.
 

WJBertrand

Ventura Highway
Joined
Jun 20, 2015
Messages
4,516
Location
Ventura, CA
Sounds like your flash is still using O2 sensor input instead of being turned off? A telling clue is the stall once it idled for a while. The ECU runs open loop until the engine starts to warm and it goes into closed loop, where the ECU expects an O2 sensor signal. Any error codes?


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sergeyd

Member
Joined
Sep 30, 2020
Messages
47
Location
Los Angeles
Re: Very hard starting today

I just bought a new '14 Super Tenere ES. I won't be picking it up until our snow is gone.

I had the hard start issue a couple of times with my '04 FJR1300, which was new in August of '03.

At that time, there was nothing documenting the issue online. I tore the bike apart to get her going. I removed the tank, plastics, dash, plugs, etc. She was definitely full of fuel.

What finally worked was holding WOT with a fully charged battery. When she fired, she FIRED! It sounded like a pair of shotguns going off.

I've also had it happen on a pair of V-Strom 650's, one was my wife's '05, the other my '06. As soon as issue reared it ugly head, simply opened throttle and hit starter. Fired right up.
I'm having a problem of starting the bike and I think your method should work. But what is WOT? Search doesn't help
 

cyclemike4

Well-Known Member
Joined
Sep 18, 2016
Messages
815
Location
ky
After years of owning this bike i had my first hard start. Not sure why it is called that because it is no start. I started it just for a few seconds then it sat for 3 days. I have done the quick starts all along and never had any issues. I didnt waist my time pulling the fuse being i have 90000 miles on these plugs and i have new ones. Just as a test i reached under the tank and opened the butterflies with my fingers (because wide open throttle doesnt open them when it is turning over) and it fired right up but was loaded up and i couldnt control the butterflies with my fingers after the servo motor took over. Any way new plugs new air filter and it is top notch again.
 

jbrown

Active Member
Joined
Sep 25, 2012
Messages
373
Location
Novato, CA
A note about holding the throttle wide open while cranking to start a flooded engine: The supposition is that the ECU recognizes this input as a special situation and limits/stops the injectors to help clear a flooded engine. The supposition is backed by the knowledge that this is what some other fuel injection systems do. There is no confirmation from Yamaha or any flash software I'm aware of that proves this is actually done., but anecdotal evidence does suggest this is the case. If this is true, there is no need to force the throttle valves open while cranking, the small amount the ECU opens them is good enough as long as fuel isn't being added.
 

cyclemike4

Well-Known Member
Joined
Sep 18, 2016
Messages
815
Location
ky
I really don't know what the manufacturers do with all the soft ware they put in these things. In my case just the one observation of the incident because it is the only time I have had it happen. I did a short start just to move the beast instead of pushing it up hill. It sat for 3 days. Next time it would not start and I could smell gas heavy. I held the butterflies open then just for the heck of it to see what would happen. It did hit and if i could have modulated the intake air my self I think it would have cleaned up after a while. I jumped on my DR 650 and used it for two days till I had time to change the plugs. when I finally got around to pulling the plugs they were still wet and heavy with gas. So in my case it was throwing cold start fuel with very little air flow on fouled plugs just what it didn't need. It didn't hurt to have new plugs in it any way. I do think I am going to do something different with that crankcase breather. Sometimes when i have the air box off i don't have much issues with that hose and other times it is the worst pain of the job. I think I may just plug the hole on the air box and find a new hose with a external filter for it.
 

Skytower

Active Member
Joined
Jun 9, 2020
Messages
172
Location
Norfolk, VA
I don't know if I mentioned it before, but some of the hard starts I've run across on other vehicles we're from faulty temp sensors. The intake air, or coolant temp sensors were inaccurate, but not far enough out to cause a fault. This resulted in an incorrect fuel mix for the given actual conditions.

Just another thing to check prior to pulling hair, and throwing parts at it
 

Cycledude

Well-Known Member
Joined
Jan 29, 2016
Messages
3,999
Location
Rib lake wi
Just another reason why Yamaha will most likely discontinue the 1200 Tenere, way to many hard start complaints along with the very lousy headlights.
I‘ve been lucky only experienced the hard start issue with my 2013 twice and fortunately both times it happened at home in my garage, fortunately it’s never happened to my 2018 but I now carry one of those battery pack things just in case it does happen someday.
 

NJGreg

Member
Joined
Aug 7, 2021
Messages
56
Location
South Jersey
I may as well in here also. 2021 model 9600 miles. I do believe I cycled the ignition switch several times as I had installed a fuse box under the seat and tested stuff out.

Had a hard start took me over a week to get figure out/get going.
Would not start after sitting for a week in the cold snap we got down to single digits. Was turning what I thought was a wee bit slow so ordered a solar trickle charger that took a week to come. Got battery charged up and quicky killed it trying to start. Ordered an antigravity battery to install. I had to loosen up my altrider bars to wiggle old battery out out and new in.

Proceeded to discharge the antigravity battery down to the point it shut off. Tried with fuel fuse removed and once engine tried to start with out it, put fuse back in. Hit the boost button and was able to get a couple more cranks out of it and stopped there.

Ordered a plug in trickle charger and topped the lithium battery back up.

Got it started by removing the fuel fuse again, then cranked it 6 times for 6 seconds each. Reinstalled the fuse, tried to start and it sputtered but I let off the start switch. Hit the switch again and went WOT and it screamed to life.

Went out for a two hour ride afterwards stopping/starting no less than 6 more times with out hesitation.
 

StefanOnHisS10

Converting fuel into heat, noise and a bit motion
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Apr 8, 2020
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2,159
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The Netherlands, Friesland.
Wasn’t it the fuel that had gone bad because of the cold? Don’t know exactly how to describe what I mean but when fuel gets really really cold it can freeze, disintegrate etc.
 

NJGreg

Member
Joined
Aug 7, 2021
Messages
56
Location
South Jersey
For me, I had gotten fuel about a week prior and not from a budget station. Later attempts to start a week later had temps around 60F
 

TenereGUY

Well-Known Member
Joined
Jan 19, 2023
Messages
993
Location
Illinois
Wasn’t it the fuel that had gone bad because of the cold? Don’t know exactly how to describe what I mean but when fuel gets really really cold it can freeze, disintegrate etc.
Fuel won't freeze. If you don't store your bike with a full tank the moisture in the air condenses when it gets cold and that water falls to the bottom of your tank and freezes or sticks to your tanks and if long enough rust starts to form. If the water gets in a fuel line then it freezes and blocks fuel flow. This is known as gas line freeze. That's why they sell stuff to absorb the water before it can freeze (think yellow bottles). Alcohol gas is a problem if not treated and sometimes still causes problems. The alcohol separates from the gas and causes problems especially in carburetors. Small white deposits form and they clog up small fine orifices. I won't store my bikes with alcohol gas... just pure gas. To find out where the nearest station to you is... go to pure-gas.org. It's hard to find in Illinois but this site is wonderful.

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StefanOnHisS10

Converting fuel into heat, noise and a bit motion
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Apr 8, 2020
Messages
2,159
Location
The Netherlands, Friesland.
Fuel won't freeze. If you don't store your bike with a full tank the moisture in the air condenses when it gets cold and that water falls to the bottom of your tank and freezes or sticks to your tanks and if long enough rust starts to form. If the water gets in a fuel line then it freezes and blocks fuel flow. This is known as gas line freeze. That's why they sell stuff to absorb the water before it can freeze (think yellow bottles). Alcohol gas is a problem if not treated and sometimes still causes problems. The alcohol separates from the gas and causes problems especially in carburetors. Small white deposits form and they clog up small fine orifices. I won't store my bikes with alcohol gas... just pure gas. To find out where the nearest station to you is... go to pure-gas.org. It's hard to find in Illinois but this site is wonderful.

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I knew that, but didn’t bother typing that all out. Just summarized it as “freezing”.
 
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