Hello all, I have been riding any and all motorcycles for 48 years now, I currently have a 96 VMax, 01 Valkyrie, and 86 Honda Elite 250 (scooter)

[Todd Chapman]

The vmax i have has suddenly stopped starting. It was doing fine but now when I push the start button, the headlight dims and the switch is fine, but there is no priming of the fuel pump and no power to the starter solenoid. I am sure it is probably something simple but for the life of me have been unable to figure out the problem. The previous owner tied the clutch lever safety wires together (assume to bypass the safety switch). I have checked all fuses, replaced the starter relay, etc. My question is are there any known issues that I might track down? thanks in advance!

 

[Fire-medic]

Electrical system grounds, I always start with grounds, and load-testing a battery and reading the results.

 

[TK3333]

Kickstand safety switch also, but you should still hear the vboost cycle and fuel pump prime.

 

[Todd Chapman]

thanks, I will check the grounds, are there any known locations that can cause problems?

 

[Fire-medic]

Any connectors in the circuit that you suspect of giving you trouble, I'd separate the male/female connectors & use sandpaper and pliers , maybe some DEOXIT spray to clean to shiny metal, make sure the M/F connection is snug, and any corrosion is removed. Also, I've found on crimped connections, that where the crimp is, the strands may break because of chafing against something, of being stretched beyond their normal position, or from corrosion eating-away at the wire strands. Sometimes the break can occur underneath the jacket insulator, the PVC sleeve in-which the conductor strands are.

Flexing the wire along its length, looking for a break in the continuity using a tester, is something else to do, 1 wire at a time.

Here's the main harness ground, by the oil filler:



There are other grounds.

When you get this straightened out, use the search function to read about the Cobra slip-on exhausts. Installing the OEM exhaust will give you probably a 10% horsepower boost. Read the posts.

A start: Cobra Pipes and jetting.

However, if you like the Cobras because they 'look cool,' that's OK, your bike, your choice. Most people who buy a VMax get it because they enjoy the performance. When a simple system swap-out gives you a ~10% boost in horsepower, well, there you go. The OEM exhaust throttle response is different too, for the better. One thing you need to check upon is if the carburetors were re-jetted for the Cobra slip-ons, which some people do. Here are the OEM specs:


Help seeing what's what:
https://www.ronayers.com/oemparts/a/yam/50045c0ef8700209bc7942f3/carburetor
Why does the aftermarket slip-on exhaust make less horsepower than the OEM exhaust? Bear in-mind a 'slip-on exhaust' is the muffler canisters array, the header pipes from each cyl head are the OEM. On a stock VMax, there is an exhaust resonator box beneath the engine, which helps provide better management of exhaust gases. The engineering is designed to allow optimal scavenging of exhaust gases. The discharge of one cylinder's exhaust helps accelerate the flow of the next paired-to-it cylinder's exhaust. The 'early-firing' cylinder's exhaust gas flow helps pull-along the 'later-firing' cylinder's exhaust gas flow. Also, designed exhaust back-pressure helps contain the fuel/air mixture in the combustion chamber so it burns more-completely. This is an important part of valve 'overlap' when both the intake valves and the exhaust valves are open at the same time.

Newer systems for promoting intake and exhaust flow have been used on newer bikes and other vehicles. Variable valve timing, variable inlet lengths, and variable exhaust lengths and volumes are now used. Of course, fuel injection of increasing sophistication also helps power output.

The Cobra system does-away with the scavenging provided by the OEM design. Horsepower is adversely affected. But "look at those four shining pipes!"

 

[Todd Chapman]

thanks for your quick response, looks like I am going to have to check the wires one at a time, my favirite hobby when I'm not working

 

[Fire-medic]

Note the overlap.

 

[Todd Chapman]

well after hours of going through the wiring harnesses and replacing relays and fuses, etc. and even purchasing a newer vmax wire harness, mine is a 95 went to a 02, finally figured out where the problem was. The ignition key switch was not making proper contact to allow the power to reach both the fuel pump and the ignition coil switch! Haven't replaced the switch yet, looks like a bear to remove so instead bumped the ignition box fuse from 10 amps to 15 so it would quit blowing. Anyway thanks for the advice fire-medic and tk333, much appreciated maybe this will help someone else in the future. If the key is turned just right to the on position it immediately sends voltage to the left underscoop starter relay switch now. Found it by accidentally turning key on and off lol