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Discussion Starter #1
My 03 ST4s has always been on the slow cranking type. Sometimes very very slow. Many times it won't start.

So, when I had the fairing off for some maintenance, I took a look. All connections good and tight. The battery measured 13.4v prior to trying it.

I pulled a fuly charged battery at 13.4v and my car jumper cables. I hooked the positive directly to the positive lug of the starter and the negative to a good engine bolt. Still the same.

Am I looking at a slightly toasted starter motor? Seems I've bypassed the other possible culprits. Is there a service procedure for cleaning the internal contacts or look for another on EBay?

BTW, is it straight forward taking the starter off or do I have to take the alternator cover off to release/remove something? :frown2:

Steve
 

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You'd have to pull the alternator cover.

Have you eliminated the solenoid as a possibility? If not, then jump the terminals with a big screwdriver. You could also run battery power right to the starter. Keep the key off and run the jumpers from your battery to a frame ground point and the actual starter connection.

Don't forget cables too. You may have the connections tight and clean, but OEM cables have poor connections (terminals to wire crimp) and are subject to cause high resistance resulting in slow starting. Upgraded cables, Powerlet or some of the other more expensive options, are a good thing to do anyway.
 
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Discussion Starter #3
You'd have to pull the alternator cover.

Have you eliminated the solenoid as a possibility? If not, then jump the terminals with a big screwdriver. You could also run battery power right to the starter. Keep the key off and run the jumpers from your battery to a frame ground point and the actual starter connection.

Don't forget cables too. You may have the connections tight and clean, but OEM cables have poor connections (terminals to wire crimp) and are subject to cause high resistance resulting in slow starting. Upgraded cables, Powerlet or some of the other more expensive options, are a good thing to do anyway.
Yes, solenoid eliminated as I used car jumper cables and a spare charged battery directly connected to the starter and the frame. No diff.

The cables are upgraded something. Not OE, but I couldn't read the markings. IAE, they were bypassed by this process.

Difficult to address starter release once cover removed?

S
 

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Then I'd say you're on the right track with the starter. I believe there are three bolts holding it from the inside. Haven't had one of these starters apart, but I have done a few car starters. You may be able to access the brushes and clean things up. If not, they are on eBay all the time.

I think I can remember reading about someone rebuilding one on these forums. Try searching, or maybe it was someone here and they will pop in.
 

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Discussion Starter #6

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Just to be sure, why not try a big car battery, and get decent connection to the chassis with the (-). Then, touch the + lead to the starter post, and see if she cranks any faster.

This eliminates your bike battery, and all the wiring, including the ground wire to the block.

Another thing you could do is try to measure the small voltage from battery (-) post to chassis, while cranking. If it's more than like 0.25V, you gotta find the resistive point in the circuit. Same for the + wire. Measure from +post of battery (not the wire, but the Pb lead (pronounced led) post!) to the + post on the starter while trying to crank.

Also see what the battery voltage looks like while you're cranking.
 

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Discussion Starter #8
Just to be sure, why not try a big car battery, and get decent connection to the chassis with the (-). Then, touch the + lead to the starter post, and see if she cranks any faster.

I had a well charged large MC battery from a SuperSport 900 13.4 volts. I hooked the jumper cables to it and then directly to the starter positive lug and a good frame bolt. No difference in cranking.

This eliminates your bike battery, and all the wiring, including the ground wire to the block.

Agreed. Totally trying to spin the starter with an outside battery. Same result as the ST4s battery.

Another thing you could do is try to measure the small voltage from battery (-) post to chassis, while cranking. If it's more than like 0.25V, you gotta find the resistive point in the circuit. Same for the + wire. Measure from +post of battery (not the wire, but the Pb lead (pronounced led) post!) to the + post on the starter while trying to crank.

I'll measure the cable resistance as you've noted. But connecting the starter directly to a battery should indicate the problem has nothing to do with the cables.

Also see what the battery voltage looks like while you're cranking.
It drops down to the 8-9volt range.

Thanks very much for comments and insight.

S
 

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Again, just clean the starter. Unless something else is going on, which appears unlikely, this is a free easy fix.
 

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OK, sounds like you did try with another battery. But bike batteries tend to be on the low end of things when it comes to CCA, so that's why I recommended an auto battery.

My feelings about the 8-9V out of the battery when cranking aren't good. It could be that the starter is trying to draw excessive current, and the battery just can't deal with over 200A.

I recently had a Moto Guzzi starter that just "stopped cranking". Sounded like the bendix was engaging (and indeed it was). But no spin-a-roonie. Gent's on the V11 forum mentioned that it "wasn't uncommon for the permanent magnets (stator) to come unglued." My clamp-on ammeter showed over 200A trying to flow. It was the magnets - one fell, stuck to the armature, and jammed.

Another weird fact about our ST's: The ST2 and ST4 with the older "chip" ECU would allow the starter to crank until the battery was almost dead. Our newer ST4s, with the small ECU (5.9 ??) will only crank when there's sufficient ECU voltage. I'm not sure what "minimum" voltage is, but I know my ST4s found it one 20 degree day after work. I'm pretty sure the solenoid command comes via the ECU on the 5.9.

Note that a DC Clamp-on Ammeter can be bought at Sears (Craftsman brand) for $60. Fluke equivalent is hundred$ more!
 

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Steve, any resolution?
 

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Discussion Starter #12 (Edited)
Yes, seems the starter was the problem. I just didn't want to go thru the aggravation of taking it apart and running the risk of failure and doing all the work again.

I rec'd the new starter Monday and:
**drained the oil;
**drained the water;
**removed the hoses attached to the alt cover;
**removed the crank sensor (careful not to loose any spacers);
**removed the cover successfully (I use a piece of cardboard w/an outline of the cover having the holes drilled into it to keep the bolts properly organized);
**pulled the three starter bolts (starter idler gear spins easily to orient the access hole to one of the bolts), removed the starter cable;
**pulled the starter and installed the new one with the OE gasket between the starter and the case. Use grease on the starter flange when installing the gaseket to help keep the gasket and its holes properly oriented.

Then reversed. Once starter installed, I tried it. Cover off, no oil and no water. It cranked very nicely for a second or two. Certainly, I didn't let it start, just wanted to check it for operation and success.

A little bit of time to do it all and use the gasket liquid (3 Bond IIRC).

Haven't yet installed the oil and new filter or the coolant. That shouldn't be too much of an issue.

In the end, it was the time and effort leading to getting a new starter. $113 total cost and free ship. To me that's worth the possibility of not doing a 'good enough' job on cleaning the starter.

Thanks for the comments.

Steve
 

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I went through exactly these symptoms about a year ago. EVERYTHING pointed to the starter. Did direct connects with a deep cycle auto battery and nothing. Turned out to be the Solenoid. For some reason it is especially difficult to get good connections on the small starter positive post and case ground with traditionally sized jumpers. Drain the sump and remove the side cover to get out the starter only to have it run perfectly on the bench. Rebuilt the brushes which were original and looked serviceable after 28K miles and put it all back together. Even with the side cover off and no real drag on the starter, still nothing when jumped directly from an auto battery with direct connections.
Frustrated I went through the whole system and found a solenoid on the way out with very wobbly/disconnected posts and toasted pos and neg harness cables that I swapped out with hand made 6 gauges units.
Bike starts great now, physically check the solenoid and the seating of the exciter wires to the solenoid.


Yes, solenoid eliminated as I used car jumper cables and a spare charged battery directly connected to the starter and the frame. No diff.

The cables are upgraded something. Not OE, but I couldn't read the markings. IAE, they were bypassed by this process.

Difficult to address starter release once cover removed?

S
 

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I also went through the same symptoms over the last few months and was getting quite fed up. I ordered a set of brushes for the starter at less than the price of an oil filter and spent less than an hour fitting them. The bike is now perfect again.I even took some photos and blogged about it!
 
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