guzzi lemans starter wiring

[jedijoy13]

Hello,

I am trying to get my 850 lemans III back on the road. today was to be the trial start.  although, when i went to start, it just clicked.  I'm ok with wiring, but am not sure i've got it wired correctly.

so, i know the "click" means that the solenoid is getting some power.  but then nothing else, so the starter is not being activated?



i've got the top nut going to ground (battery neg). 
the bottom nut is not connected
the "terminal to the start switch (using a moto gadget m-unit)
should the bottom nut be connected as well?
or am i way off base?

[mtiberio]

WHOA...

the top nut (to the left of the upper run of the red wire) should go to the + side of the battery

the lower nut simply directs juice from the solenoid to the starter, and you'll see the short braided "wire" connecting the two. no need to touch that unless you are rebuilding a solenoid (or maybe starter).

if you hook up the top nut properly, and then pull that red wire, and then run a short jumper from the top nut/stud to the blade terminal where the red wire went, the bike should crank if your starter and battery are good. The red wire is what brings low amperage 12+ volts from the starter switch (via the starter relay) to the solenoid. The solenoid (which is part relay, it literally rams a plate across the inside expression of those two studs) switches the high amperage 12+ volts from the top nut to the lower nut on the solenoid and hence the starter. the solenoid also throws the gears together, so it is both a high amperage relay and a solenoid. The small relay often found between the starter switch and the solenoid is there to prevent the cheesy starter switch from melting from the intermediate amperage draw of the solenoid. I often remove the starter relay and heavy up the starter switch just to make things more reliable.

[jedijoy13]

great,  that seems to have done the trick.  however, i need to re-check the carbs.  it cranks, but doesn't turn over now.  i feel stupid.  guess i needed to look at that diagram again.  i believe i had the wiring the way you said the first time, but thought i was doing something wrong.  i don't have to worry about relay's with the m-unit.

[Kiwi_Roy]

When in doubt consult Carl Allison

http://www.thisoldtractor.com/guzzi007/schematics/1981_LeMans_III.gif

"Startus Interuptus"
Caused by resistance in the starter solenoid wiring. The starter solenoid inrush current is about 50 Amps
The original wiring has the contact of the Start relay fed from a fuse that's through the ignition switch, I would separate the relay coil and contact.
Leave the coil fed through the ignition switch but power the contact from a fuse directly from the battery, the schematic shows F6 not doing anything or
F5 would be good also. Failing either of those options a new 20 Amp in-line fuse directly from the battery terminal to 30 of the start relay.
(Actually they have the relay contacts backwards from normal battery - fuse - 87) Make sure the spade connectors are nice and tight.

[jedijoy13]

ok, got her started.  getting into dialing in the carbs and have another issue/question.

so i went through the owner's manual for the carb procedure and the many articles online.screwed in the idle screw, and backed out 1 1/2 turn.
started.  i increased the idle rpm to about 2k and pulled the plugs one at a time.  the right side, i believe i have dialed in.  i can get it to 1100 and not kill the bike. 

when i do the left side, i can never get it stay on.  so the problems i've been troubleshooting with the left side are as follows. note that this is all with both plugs in
idle screw - no effect until i blip the idle above 2k, then the idle screw starts working (if it's screwed in all of the way, it'll hover at 3-4k), then i can dial it back to 1100 idle
when i first blip the throttle, it sounds like chugging (research online indicates that it might be the accelerator pump not functioning correctly?), but in the higher rpms, it sounds fine

other notes, carbs were rebuilt 2 years ago, I assume they have standard jetting, but didn't check when i disassembled. 

thanks for any assistance,