If you correctly diagnose the problem, I'll send you a genuine MV Corse carbon fiber key guard for an F4.
Bike was running fine after the chip replacement. It started this morning as I was loading it onto the truck and died. Never started after that. It turns over, it won't catch.
There is spark.
There is fuel.
The ECU is fine, I tested it on another bike.
The TPS was cracked, from my leaning the bike against the door jamb, probably, but I fixed it. I even replaced it with another one and still no joy.
Ask as many questions as you like. This issue has me stumped.
Oh, yes, the exhaust smells of fuel. This is what led me to believe it was some sort of timing issue.
Everyone says if you have spark and fuel the engine will run. Well, almost. You need spark and fuel at the exact correct time. So if the injectors are squirting fuel as they are supposed to, and the plugs are firing as they are supposed to just not WHEN they are supposed to, that would lead to the no start, fuel in the exhaust smell condition.
So I set the TPS: 155mv with butterflies closed, and 350mV or so at idle. No change.
My compression test led me to believe I had serious engine problems. 75psi in one cylinder, and 145psi in the one next to it? The manual states compression should be between 7.7bar (108psi) and 14bar (200psi). Naturally, I'm thinking the worst. That's why it won't start. That's why it sounds like a Ducati turning over. So I pulled the valve cover and checked the timing marks on the cams. They are right where they are supposed to be. Level with the cylinder head. I checked the timing mark on the phonic wheel. It too is exactly where it is supposed to be. Using a dial indicator to find TDC on #1 the phonic wheel is where it is supposed to be and the marks on the cams are correct.
Well, thinks I. Must be the valves are bent or something. So I checked clearance on all 16 valves and they are also well with in spec. some are within .001 of each other.
Too many complicated things are checking out. TPS is good, valves clearance is good, cam timing is good. There is something obvious I'm missing and the more complicated the issue that checks out, the more simple the solution becomes. I just can't find it.
The compression thing does bother me. Perhaps my gauge is crap, but if so why would I get the same reading on the same cylinders 3 different times?
I'll post pics of the timing marks for y'all to look at.
Which leads to the next question...is the oil in the glass black or milky? However, with the smell of fuel in the exhaust I'm guessing it's not a cracked head gasket or head.
Just for grins, did you try new spark plugs? Like you said, the complex is checking out so time to try the simple.
Hi CAG, when i first got my 05F4 it got me home and the next day when i went to ride it, it started then died and wouldnt run again. It turned out to be a perished fuel line inside the tank. But while trying to start it i got the occasional pop from the exhaust.
I don't think it's a hose. I get plenty of fuel at the rail. In fact, I pumped fuel out of the tank through the lines into a gas can just to make sure the fuel pump was working and there were no obstructions in the line.
I did some more battery charging, Chuck. The one in the bike is at 13.13 volts the one on the bench is at 13.10.
Bike ran. Bike stopped running. Bike leaned against wall. Side stand switch bypassed. Bike never ran again. TPS damaged, but tps repaired, tps replaced, tps set to specs. That's it. I know it is something stupid simple, but I'll be damned if I can find it.
The bike ran fine last week right, since which time you have messed with one or two things? When exactly did you bypass the side-stand switch and has it run reliably since?
Possibly try putting the side stand back on and plug the switch back in and also swapping ecu's.
Several times, Rob. I don't think that's it. I think it is worse than that.
Using my ghetto leak down tester, (an air hose connected to a fitting threaded directly into the cylinder head) 80psi of air blows out of the intakes. On the compression stroke, it is a little air but it's there. On the intake stroke it's gale force.
And on the cylinder with the highest compression, the 80 psi of air will actually spin the crank a few degrees.
Here's an idea, Pollyanna: maybe the valves just have a lot of carbon build up and are not bent after all! Maybe they are just not seating properly and I can clean the carbon off and all my troubles will disappear?
I think it may be time to go back to the basics...drink a shot of your favorite alcohol, the higher the proof the better. Then pick up a hammer, mallet, wrench...whatever is handy...and start hitting random parts of the MV, preferably things that are hard and don't dent or scratch (engine, frame, tire, etc). At the same time, scream as many four letter words and their derivatives as possible at the top of your lungs. If possible, stop and kick something for proper affect. I've found these actions tend to scare my MV into acting like a motorcycle and functioning for a short time. However, if it doesn't work, I feel better about myself and where I stand in the universe. Proceed and good luck!
I drew the rain turtle, but did a Jig. I thought that was the same as a dance. Crap. I'll bet that's the problem. Latch relay has been replaced and checked, it's working fine.
Carl....why do you have such disparate compression readings??? All 4 cylinders should be within a few percentage points of each other...and normal high performance I4 engines should have somewhere around 175~200 psi.
Something is bad wrong of you have 140psi on one cylinder and 75psi on another. Buy a leak down tester and see where the loss of compression is coming from.
Sorry, but I think you have covered the all the basic except one...adequate compression. You need three things for an engine to run....fuel/air mixture of approximately correct ratio, ignition spark at approximately correct time, and COMPRESSION.
Carl....why do you have such disparate compression readings??? All 4 cylinders should be within a few percentage points of each other...and normal high performance I4 engines should have somewhere around 175~200 psi.
Something is bad wrong of you have 140psi on one cylinder and 75psi on another. Buy a leak down tester and see where the loss of compression is coming from.
Sorry, but I think you have covered the all the basic except one...adequate compression. You need three things for an engine to run....fuel/air mixture of approximately correct ratio, ignition spark at approximately correct time, and COMPRESSION.
I'll check compression on an engine I have on a stand out of a bike. It's a 910 but it will at least let me see if my gauge is at fault. You would think that with compression that bad something would be broken, but I see no signs of bent valves or anything broken. Remember, it was running well enough to push it up a ramp, and then stopped. No strange noises at all.
If one cylinder is leaking the thing would still run - crappy, but it would still run.
First principles - spark on compression stroke somewhere before TDC? Check.
You have fuel supply? Check. Is it enough? Very crude, but how about some engine starting fluid down the throttle bodies? (Very volatile - if there is any spark it burns - In Oz it is called 'Start-Ya-Bastard' - true story!)
Go back to what changed - pull off the neutral switch and TPS and reassemble - check continuity. Did you check the voltage off the TPS at the ECU pin?
Another thought - did you pull the battery to change the switch and TPS? All earth straps in place, nice and tight?
Did the motor stop involuntarily or did you turn it off?
The only thing I haven't checked is timing. I'll do that today. I should have done that before I went this deep but it's a moot point. The big issue is the strange compression readings.
I really need a can of start-ya-bastard. I don't have any and have never used it.
Voltage from TPS checked at ECU pin. 157mV with the butterflies fully shut, and 350mV with them adjusted to idle position. Voltage varies with a twist of the throttle.
The bike ran fine last week right, since which time you have messed with one or two things? When exactly did you bypass the side-stand switch and has it run reliably since?
Possibly try putting the side stand back on and plug the switch back in and also swapping ecu's.
If one cylinder is leaking the thing would still run - crappy, but it would still run.
First principles - spark on compression stroke somewhere before TDC? Check.
You have fuel supply? Check. Is it enough? Very crude, but how about some engine starting fluid down the throttle bodies? (Very volatile - if there is any spark it burns - In Oz it is called 'Start-Ya-Bastard' - true story!)
Go back to what changed - pull off the neutral switch and TPS and reassemble - check continuity. Did you check the voltage off the TPS at the ECU pin?
Another thought - did you pull the battery to change the switch and TPS? All earth straps in place, nice and tight?
Did the motor stop involuntarily or did you turn it off?
What had me stumped was the widely disparate compression ratings, and yet the timing was perfect and the valves didn't appear bent.
So I cleaned the back of the valves as best I could.
I put in new plugs.
Bike fired right up.
Oil blowing out of the valve cover at this point but that can be fixed.
So cleaning the valves may have helped them seat which would solve the compression problem, and if the former plugs were marginal, the new plugs solved that.
Was it the plugs or the carbon on the valves? I don't know, but we do have a winner.
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