88 VMax igniton cuts out

[tadd34]

OK I'm going to plead ignorance here, what is the Dyna 3000? I am having ignition problems, and am wondering what to do, the bike idles/revs great until it warms up, then I lose spark in front pistons and tach goes to 0-rpm. Any suggestions?

 

[maleko89]

Re: 85 ignition problems

I would check the spark plugs, plug boots and wires. What's the resistance when measuring from plug boot to engine bolt?

 

[Akatora]

Hello. The symptoms sound just like mine. The problem was one of the two ignition pick-up coils. See http://www.vmaxforum.net/showthread.php?t=3876

Measuring the resistances is very quick and easy operation to conduct. The connector is located under the saddle, and the wiring is coming from the alternator side there. Depending on the year model there are either 5 pins or 2 pins in this connector. If 5 pin connector (1985-89), check the resistance between black wire and all the others (white/red, orange, white/green and grey) one by one (on the flywheel side of the connector). The value should be between 94 and 126 ohms in each at 20 degr. Celsius. If you have two pin connector (1990 and newer), just check the resistance between those 2 (black and orange). The resistance value should be between 81 and 121 ohms at 20 degr. Practically your readings can be something over 130 ohms, as the engine is warm and the resistance grows when temperature gets higher. The problem is clear if some reading shows infinite resistance (no continuity) or very high resistance value that is clearly out of specs.

The older model has two ignition pick-up coils around the flywheel so that one is giving pulses to TCI for cylinders 1 and 3 (rear), and the other gives the pulses to TCI for cylinders 2 and 4 (front). If one of those pick-up coils is failing, it could cause two cylinders not to fire.


So once you have multimeter available and the connector located, warm up the engine and wait until the problem occurs. When it happens, switch off the engine and conduct the measurements immediately, as the symptoms may disappear after the engine cools down a little bit.

 

[tadd34]

Well that definately sounds like a logical explanation. Thanks.

 

[Akatora]

One more good thing to check when having ignition problems are the ignition HT coils. There are four of them, one for each cylinder, and each one has got primary side and secondary side. Factory specification for primary side resistance (between red/white and orange wires) is between 2.4 and 3.0 ohms at 20 degr. Celsius. The specified resistance of secondary (HT side) is between 10.5 and 15.8 kilo ohms (without plug caps) at 20 C. This resistance can be measured between red/white wire on primary side and the actual spark plug wire (HT wire).

Anyway, it is also better to check the HT coil primary side wiring connectors (red/white and orange wire coming from HT coil), as there can be huge amounts of sulfur which can cause contact to disappear. If you find any sulfur, take the pin out carefully and brush it clean, put some corrosion spray there and then back.

 

[Akatora]

By the way, in order not to make easy mistake when reading the ignition HT coil measurement values, note that the spark plug HT wires of front cylinders are crossing - i.e. the coil located at right front gives spark for right left side cylinder and vice versa.

 

[vmax92]

hi guys
i have a similar problem
the run fine untill 5500 rpm and then cut ignition, since i let the rpm go under 5500 in fifth gear or another it starts again
i tried vboost deconnected same problem
if someone can help
regards
Philippe

 

[Akatora]

hi guys
i have a similar problem
the run fine untill 5500 rpm and then cut ignition, since i let the rpm go under 5500 in fifth gear or another it starts again
i tried vboost deconnected same problem
if someone can help
regards
Philippe

Hello,

Have you confirmed that it is an ignition problem (no spark on the plugs)? Because the symptoms sound more as if the fuel mixture setting might be too lean.

You can confirm the condition of the ignition system (firing or not) at any RPM by two means:

1) If you have a timing lamp available, connect it (pulse lead to spark plug wire, + wire to extra battery + pole and - wire to that battery - pole) and see whether the light blinks regularly or not when you give it the problematic RPM. Repeat with every cylinder. WHEN DOING THIS BE CAREFUL NOT TO LET THE PULSE LEAD TO CONTACT METAL PARTS OF THE ENGINE, FRAME ETC., AS THIS CAN CAUSE TEMPORARY IDLE PROBLEMS. Remember to use some other battery (not bike's battery) as a power source - and be careful not to touch the lamp wires during the test, as you are working on high voltage line.

2) If the timing lamp is not available, you can take the pulse reading out from the ignition HT coil's primary side pulse line (in my bike it is orange) by connecting there a wire which will be used as a power source for a LED light which could be for example ON/OFF type switch with a LED. If you use this setup, you have to also ground the switch to the bike frame. This arrangement tells you whether the ignition command is coming from the TCI unit to the coil. The LED should blink regularly (i.e. every time when the spark is being created). Repeat this for all the cylinders. If the blinking test is ok, the likelihood of ignition problem is considerably small then.

I added this kind of "test wires" into all of my ignition coil pulse wires. I put them hiding between the fake tank and the instrument panel. If I want to use them, I only have to remove the fake tank and pick the ends of the test wires. Actually I made a kind of test box which contains four ON/OFF type LED switches, one for each cylinder. It is very quick operation to inspect the cylinder firing situation same time for all the cylinders by connecting the wires to the test box. Naturally the switches or the test wires could be used for some other purpose as well, if the firing pulse is needed. It is good idea to put a marking into each test wire end to show which cylinder it is firing. Then you can immediately recognize the problematic cylinder(s) without guessing and re-inspecting too much. The test box could be also made a permanent installation (could see the situation even on the run), but the space is very limited so I keep it separated and use it only when inspecting something. For short test runs it is ok to keep the box on the fake tank.

Anyway, if the blinking (of the test lamp light or LED) is regular through the RPM range it is likely that your problems are mixture related; fuel line blockage, carb contamination, vacuum leak etc. If, however, the blinking stops (goes black) then it suggests that something is wrong with the ignition system.


Regards,

AT

 

[95spfldmax]

Hello,

Anyway, if the blinking (of the test lamp light or LED) is regular through the RPM range it is likely that your problems are mixture related; fuel line blockage, carb contamination, vacuum leak etc. If, however, the blinking stops (goes black) then it suggests that something is wrong with the ignition system.

AT

HELLO EVERYONE........

As a newbie to this site but long time Max owner with a simular problem to the above, I've got some GREAT "ammo" to do some further checks with now. I highly suspect my pick-up coils to be failing under the hottest of conditions too as my problem will run unseen for 150 miles sometimes and then show itself blocks from the house with it just surging slighting that slowly gets too noticable and IRRITATING and a bit worse (stall threatening)!!:bang head::bang head: Been pissing me off for some time now.....

But anyways.......those good sugestions and this guy here with the "do-it-yourself diagnostics tools" is why I'm in love with this board already....and it's only been DAY 1!!!!!!:clapping::biglaugh::biglaugh::clapping::worthy::worthy:

Will post back if any worthy progress is made.....stay tuned........

Good to meet everyone...will have to see if any of you are in my neck of the woods soon.....