Itinerant Air-Cooled

78 Xporter w/2L: Starter only turns the engine 1/2 or 1 turn before stopping. I can repeat this but starter is struggling to do this.
On bench, starter spins freely and solenoid shaft action seems normal.
Brushes and commutator cleaned and checked.
Ground cables cleaned and checked.

i know little about the engine, but it DOES turn over by hand normally without any resistance or noise.
Starter is original Bosch for 76-79. I assume the flywheel is 228, tho i have no way of checking.

What is the battery voltage at rest? What is the battery voltage during cranking?

Measure across the terminals directly, please! :)
Robbie

12.6 V battery is very healthy

dingo wrote: ↑

Fri Mar 17, 2017 11:07 am

78 Xporter w/2L: Starter only turns the engine 1/2 or 1 turn before stopping. I can repeat this but starter is struggling to do this.
On bench, starter spins freely and solenoid shaft action seems normal.
Brushes and commutator cleaned and checked.
Ground cables cleaned and checked.

i know little about the engine, but it DOES turn over by hand normally without any resistance or noise.
Starter is original Bosch for 76-79. I assume the flywheel is 228, tho i have no way of checking.

My guess: Voltage drop under load is causing solenoid to drop out.
Test: DISABLE IGNITION and go under bus and actuate starter with wrench across #50 spade and the big terminal. Does it crank normally? See above.
Does it die after 1/2 to full turn? Try to run motor only (bridge both big terminals).
Yes? I think solenoid.
No? Starter motor hot?
Colin

dingo wrote: ↑

Fri Mar 17, 2017 10:44 pm

12.6 V battery is very healthy

What is it during cranking?

asiab3 wrote: ↑

Mon Mar 20, 2017 1:27 am

dingo wrote: ↑

Fri Mar 17, 2017 10:44 pm

12.6 V battery is very healthy

What is it during cranking?

Maybe he ran it over himself. Did I mention to put it in neutral? Oh well.

reports of my demise were all 'fake news'....just another air cooled false flag

delays due to persistant rain and muddy quagmire of work area..so i have been focusing my energy on the interior affairs

my best guess on the starter right now is that wear on interior bush(s) causes armature to go sideways under load ?

I'm betting on worn out starter. Did you change the bellhousing bushing? Disabling the ignition will tell you a lot, whether it is the switch or wiring or the starter itself.
I've heard that the Nazis are wire "tapping" our Buses now. I blame the Socialists.

replacement starter does exact same behavior..so it aint the starter itself

cud that lil brass bushing cause such mayhem ? IF so, is there a tool / procedure for said removal/replacement. ??

im using remote starter switch.....

dingo wrote: ↑

Wed Mar 22, 2017 2:40 pm

replacement starter does exact same behavior..so it aint the starter itself

cud that lil brass bushing cause such mayhem ? IF so, is there a tool / procedure for said removal/replacement. ??

im using remote starter switch.....

Some replacement starters are MORE WORN than the one you took out. They do their best to avoid replacing bearings and they do a fine job of not locating the pinion correctly.

Loosen the nuts holding the starter. See what sort of movement you get in the bell housing flange. You might be able to experiment with different positions (yes we are talking barely a quarter of a millimeter) to find the sweet spot where it engages correctly. You could take it out and look at that bushing for ovalness. You can also hammer/twist a bolt into the bushing, vise grip the bolt and slide hammer it out . Then gently tap in your new bushing carefully. You do not want it to drop into the maw.
Colin

i shimmed the lower bolt with thin washer and got 1 turn instead of 1/2, then loosening the top bolt i got 1.5 turns...but no other arrangement got more. Shimming the top bolt got me nada.
Extracted old bush, in two sections..must have been pretty thin. Whacked in new one but it broke on re-entry...i thought i cleaned it out good, or maybe the shouldered socket driver was inadequate? anyways...extracted that one and ready for a fresh try soon as i get one

dingo wrote: ↑

Thu Mar 23, 2017 4:33 pm

i shimmed the lower bolt with thin washer and got 1 turn instead of 1/2, then loosening the top bolt i got 1.5 turns...but no other arrangement got more. Shimming the top bolt got me nada.
Extracted old bush, in two sections..must have been pretty thin. Whacked in new one but it broke on re-entry...i thought i cleaned it out good, or maybe the shouldered socket driver was inadequate? anyways...extracted that one and ready for a fresh try soon as i get one

I SAID GENTLY, I KNOW I DID.

starter bushing in...was better but still not getting past 1 or 2 revs. My last gasp was to assume Batt gnd cable, tho externally good, was somehow compromised. I ran a 2nd cable from B- to starter bolt, and finally the starter spun in sluggish but normal fashion.. perhaps my battery is now tired of all these shenanigans..but i got readings of 90,90,90,100. Could lazy hyd ;lifters cause erratic comp. readings ?

dingo wrote: ↑

Mon Mar 27, 2017 4:36 pm

90,90,90,100. Could lazy hyd ;lifters cause erratic comp. readings ?

Yes.
Colin