I've only had my BD for about 7 months. I'm still learning, so I'm hoping you guys can steer me in the right direction(s). Finally, after 2 months rehabbing from a somewhat minor back surgery, I was able to take a short ride a couple of days ago. However, this would be my 1st ride in 95+ degrees, so I'm not sure how that might have played into the issue. Total ride was about 40 miles (30 miles open road / 10 miles moderate traffic & a few stop lights). I stopped 20 miles out, for about 30 minutes, then rode 20 miles back. Bike seemed to be running great. On the last 1/4 mile of road before turning into my neighborhood, I'm feeling pretty good about life & open it up little bit more than usual. When I let off the throttle, to slow down & brake to turn into my neighborhood, the engine shuts off / oil light comes on (could've been the other way around). Bike would not fire. I sat there for a few minutes, but to no avail. It's now 100+ degrees, so rather than sit in the glaring sun, I decided to push / walk her home the last few hundred yards (so much for my back surgery). Forgot to mention that I did check the oil before setting out on my ride, after warm up. No issues there. After a few hours I went back out to the garage & the bike fired up fine. No oil warning let. I let it idle to operating temperature and checked the oil level again. No issue. I've repeated that 3 times since then. No issues, but I haven't taken another ride yet. Was thinking about checking the tappet screen & perhaps going ahead and changing fluids early. Anyone have any thoughts? Appreciate any & all input - Mike
Engine shut down 2008 Mastiff EFI (overheat?)...
- Thread starter TexasMike
- Start date
My thought is the ambient and someone boiled the bubble of air not gas? More HP, more heat. So here come the cant/can:
Can't be engine damage ~ You heard nothing strange sounding, nor saw oil smoke on startup.
Can't be the tappet screen ~ Engine starts and is not noisy.
Cant' be compression loss or spark ~ Engine starts right up.
Can be narrowed down to fuel ~ After the cooling of the engine, it starts as normal.
Can be a boil-bubble at the fuel line ~ The 'ol vapor lock story.
Can be the the combo of both ~ the ambient, the hot rodding, the fuel line, carb body took the heat.
Here at coke can my shield... be riding not walking between the fill in the blank. That, or a can of dust-off with a hose down to the front of the carb so the air pushes back over the carb, plus a Y connector spraying that fuel hose... and the can sits upside down for frosty fingers here it comes.
EDIT: Okay, it's EFI, so say steel hose, fuel rail... shield/frosty still apply too... buy a temp gun and find out who is the hottest area? Doubt it's injectors if they stick out in the air. Do not have a clue what the EFI setup looks like? Copy of HD's? Either way, it's thermo induced... cools, goes back to normal.
Can't be engine damage ~ You heard nothing strange sounding, nor saw oil smoke on startup.
Can't be the tappet screen ~ Engine starts and is not noisy.
Cant' be compression loss or spark ~ Engine starts right up.
Can be narrowed down to fuel ~ After the cooling of the engine, it starts as normal.
Can be a boil-bubble at the fuel line ~ The 'ol vapor lock story.
Can be the the combo of both ~ the ambient, the hot rodding, the fuel line, carb body took the heat.
Here at coke can my shield... be riding not walking between the fill in the blank. That, or a can of dust-off with a hose down to the front of the carb so the air pushes back over the carb, plus a Y connector spraying that fuel hose... and the can sits upside down for frosty fingers here it comes.
EDIT: Okay, it's EFI, so say steel hose, fuel rail... shield/frosty still apply too... buy a temp gun and find out who is the hottest area? Doubt it's injectors if they stick out in the air. Do not have a clue what the EFI setup looks like? Copy of HD's? Either way, it's thermo induced... cools, goes back to normal.
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Mikeinjersey
Well-Known Member
The oil light coming on was just because the engine died. Your problem is most likely not related to oil but it never hurts to check the screen.
Failure description, dies when hot and won't restart until engine cools down.
Very good chance your problem was heat related. The crank sensor, which sends the signal to the ignition to fire, can become sensitive to heat and is a main possibility for your issue. The sensor can be tested but if the issue is intermittent , which yours' would be considered, it's very hard to be certain if it's good or bad. The failure may only happen when the sensor gets hot. Pull the sensor out to clean and inspect for cracks. If you have another failure replace it. https://www.bigdogpartskingpin.com
Make sure your battery connections are clean and tight. It's also good to check your connections to the EHC and replace the dielectric grease ( good maintenance).
No. Bike starts back up when cold.
Can't be the gas cap if it starts right back up and never Atmo Locked at the cap's vent hole as a variable.
Can't be the crank sensor being it's either or... I repeat, it's either or.
Take this scenario for an example of a 'come-back' on the misdiagnose:
TexMike describes the complaint and now a short abstract on the service write-up. Customer gets the bill; new gas cap, new crank sensor, screen cleaned, oil sending unit changed, and, AND, the heat wave is still on!
Tex is in and out in one day. Goes for a ride, repeats the same exact ride, same ambient and it stalls after a hee-haw ride. Bike cools off, restarts, goes back to the shop = COME-BACK.
Signed,
Turtle Talks No One Listens
Can't be the gas cap if it starts right back up and never Atmo Locked at the cap's vent hole as a variable.
Can't be the crank sensor being it's either or... I repeat, it's either or.
Take this scenario for an example of a 'come-back' on the misdiagnose:
TexMike describes the complaint and now a short abstract on the service write-up. Customer gets the bill; new gas cap, new crank sensor, screen cleaned, oil sending unit changed, and, AND, the heat wave is still on!
Tex is in and out in one day. Goes for a ride, repeats the same exact ride, same ambient and it stalls after a hee-haw ride. Bike cools off, restarts, goes back to the shop = COME-BACK.
Signed,
Turtle Talks No One Listens
Jwooky
Well-Known Member
This. Don’t just guess or listen to others guess. Go through a diagnostic procedure.
Mr. Wright
Knows some things
Quit listening to the dooms day guys. Start simple and cheapest. Pull your gas cap off, put it to your lips and blow. If you can blow through it, more than likely it didn't vapor lock. My money is on the crank sensor. Had the same thing happen on a 09 K9 last month. Crank sensor tested good, but when it got hot, the bike shut down.
I appreciate everyone's feedback. I'm going to take all into consideration & start simple as suggested. After thinking back over the initial ride, I do recall that when I stopped for fuel (1st stop), the bike did not fire on the 1st two attempts. 3rd time was the charm (that's the first time that's happened). Then, after the 1st red light stop, the engine did backfire once between 2nd & 3rd gear (also has never happened before, but did not occur after that). I'm going to check the gas cap, crank sensor condition & clean the tappet screen, just for good measure. Battery terminals are tight & clean. After reading through some other post, I'm leaning towards that pesky crank sensor. The bike only has a little over 3K miles, but it is 13 years old now & that's never been replaced that I'm aware of.
knothead
Second Chance Customs
I agree with Shannon....i have had this issue with these bikes thru the years and 99% of the time it was the crank sensor....earlier years used a cam sensor and it was the same with those year models also.....i have a stock pile of parts and would change things out to test the bike, even change the ehc and it would still do it....when i changed the cam or crank sensor problem was fixed with the heating issue of the bike not running or dieing from heat
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Jersey Big Mike
100K mile club
The only other suspect I can see other then the crank sensor would be either some questionable gas or problems with the tank liner given how long it sat.
I'd grab an endoscope and check out the tank just to be sure.
Did you try and start it after walking it home right away or just go rest the back?
I'd grab an endoscope and check out the tank just to be sure.
Did you try and start it after walking it home right away or just go rest the back?
So first test failed... Cannot blow air through gas cap. Definitely susceptible to vapor lock. I had this bike shipped from CA in December. I removed all the emissions crap & plugged the ports on the intake backing plate & throttle body. When I went to remove the hose running to the tank, I found that it wasn't actually connected, and the port under the tank was plugged. At that point I just "assumed" that the prior owner had performed some type of of halfway removal, so the bike must have a working vented gas cap. Never bothered to actually check. Having only ridden the bike in <90 degree weather, until a few days ago, I just never had an issue with it. I'll go through the other checks as well, but definitely need to get a vented gas cap before attempting another hot ride. - Mike
Tex, you said you gave it a hot lap and that right there should have nosedived on you. Suck and blow... it's a one way switch. That says you blew thru both open ends and you are saying it's now locked both ways?
Someone take the Atmo Lock challenge. Plastic wrap is real thin so you top off the gas tank, put the cap back on with the wrap covering the vent hole in the gas cap... Bet me a beer you won't make it past two blocks or less.
Someone take the Atmo Lock challenge. Plastic wrap is real thin so you top off the gas tank, put the cap back on with the wrap covering the vent hole in the gas cap... Bet me a beer you won't make it past two blocks or less.
Gotcha... Need to test air flow both ways... Looks like this the same gas cap that others have had issues with, that I've seen in other posts.
Tested air flow with white center piece: Could not get air to pass through when "blowing". Barely able to get a very limited amount to come through when "sucking".
Removed white center piece, as suggested in other posts, and tested: Was able to get air to pass through both ways with no restrictions.
Should I just toss the white center piece & use cap without? Seems to be what others have suggested in other posts. Or, should I purchase a new gas cap?
Removed, cleaned & inspected crank position sensor. Did not find any visible issues.
Tested air flow with white center piece: Could not get air to pass through when "blowing". Barely able to get a very limited amount to come through when "sucking".
Removed white center piece, as suggested in other posts, and tested: Was able to get air to pass through both ways with no restrictions.
Should I just toss the white center piece & use cap without? Seems to be what others have suggested in other posts. Or, should I purchase a new gas cap?
Removed, cleaned & inspected crank position sensor. Did not find any visible issues.
It's not the cap. You made it vent. Atmo is going to slowly follow the vac and it goes neutral as a slow balance. And when I mean the speed of nature, place hand or nutsack against a carb opening and start the engine. That kind of speed and power going back to 14.7 psi. Would I mess with the cap? Not I said the more escaping fuel vapor goes knocking at my piston dome.
And you think closed loop venting is a bad thing? Show me and I'll show you:
Looped ~ Tank pressure inside on a cold day is not about to override the diaphragm and push vapor out past 14.7.
Opened ~ Vapor leaves 24-7 hot or cold.
Signed,
Ain't my bike
Mr. Wright
Knows some things
Unscrew that white piece and throw it away. That has been a problem on many bikes.