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turns over very slowly when hot

Started by karl61, July 28, 2010, 11:21:02 AM

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karl61

regarding my 84 FJ1100 - any one have issues like this before. It starts fine when it is cold but if I pull off the road to get gas it pauses when I hit the starter and then slowly starts to turn then fires up. Today it really turned over slowly, slower than usual but then started up so I am going to charge the battery but it still doesn't cure the pause and slow turn. It also jumps forward (slightly)  when starting when cold..not sure that that is all about.

andyb

Check the battery.
Rebuild the starter.
Clutch is sticky when cold sometimes.

racerman_27410

you can also try cracking the throttle a bit while cranking.... sometime mine gets a bit finicky when hot even with a new battery,


Kookaloo!

Frank

SlowOldGuy

Start it in neutral!  That will minimize the drivetrain drag.

DavidR.

RACER111V

I had been having the same problem for a while.It got to the point that I had to bump start it a few times.I took apart and cleaned all the connections on the way to the starter.Battery to cable,cable to solenoid,solenoid to cable,cable to starter.Now I just touch the button and it fires almost instantly,hot or cold.

Lotsokids

I'm going to resurrect this topic - mine's doing the exact same thing. I just bought a new battery, charged it up and have the same problem. I suspected my starter solonoid as I've seen solonoids fail repeatedly on cars with headers running next to the starter. I'll clean the connections first, then let you know.

Mine fires up INSTANTLY when cold, but when it's hot, it turns over very slowly - barely at all.
U.S. Air Force sport bike instructor (initial cadre), 2007-2009

I'm an American living & working in Hungary

SlowOldGuy

There's no starter solenoid on the FJ. 
The starter engages a one-way lockup sprag clutch to crank the motor.  When the engine catches and outruns the starter, the clutch automatically disengages.

Try disassembling and cleaning the starter motor or crack the throttle slightly when cranking hot.

DavidR.

DailyDriver

Quote from: SlowOldGuy on April 08, 2011, 05:56:32 PM
There's no starter solenoid on the FJ.  DavidR.

There is on the '86-'87 California model.
Only a motorcyclist knows why a dog sticks its head out the window of a moving car.

racerrad8

Quote from: SlowOldGuy on April 08, 2011, 05:56:32 PM
There's no starter solenoid on the FJ. 

Sure there is, on every FJ and it is mounted to the battery box.


I have never had a bad one, but I have sold & replaced a ton of starters. The early starters use a two magnet system within the starter. That has since been updated to a four magnet system to give the starter more torque.

The other issue is the flow of electricity on the ground side of the starter system. The ground wire from the battery grounds directly to the rear case bolt which must be tight & clean. The issue comes where the starter is mounted to the case with the two tabs. The two tabs on the case a machined bare aluminum.

The starter end plate/mounting tabs on the other hand are painted. The sole source for the starter to ground to the case is reliant on the mounting bolts "digging" in and cleaning some of the paint away to complete the circuit.

I personally clean the paint from the back side of the mounting tabs where they contact the case to ensure the ground side is allowing the full flow of electrical continuity.

If you do that and it still cranks slow, you need to get a new starter as all of the new ones today are the high torque units.

Randy - RPM
Randy - RPM

SlowOldGuy

Quote from: DailyDriver on April 09, 2011, 12:47:17 PM
Quote from: SlowOldGuy on April 08, 2011, 05:56:32 PM
There's no starter solenoid on the FJ.  DavidR.

There is on the '86-'87 California model.
Just what are you calling a solenoid?  There is a starter relay, but that's not a solenoid.  The FJ starter works through a starter clutch.  It has no solenoid.

DavidR.

Marsh White

Quote from: SlowOldGuy on April 10, 2011, 11:36:59 PM
Quote from: DailyDriver on April 09, 2011, 12:47:17 PM
Quote from: SlowOldGuy on April 08, 2011, 05:56:32 PM
There's no starter solenoid on the FJ.  DavidR.

There is on the '86-'87 California model.
Just what are you calling a solenoid?  There is a starter relay, but that's not a solenoid.  The FJ starter works through a starter clutch.  It has no solenoid.

DavidR.

I had to look it up:
http://en.wikipedia.org/wiki/Starter_solenoid

Appears to be semantics we are talking about here.  Seems "Starter Relay" and "Starter Solenoid" are fairly interchangeable.  What they describe as a "Starter Solenoid" on wikipedia (I know - not the most reliable source) sure sounds like what we have on our FJs to me...but I'm not a mechanic or engineer or anything...

rktmanfj

Quote from: Marsh White on April 11, 2011, 12:37:43 AM
Quote from: SlowOldGuy on April 10, 2011, 11:36:59 PM
Quote from: DailyDriver on April 09, 2011, 12:47:17 PM
Quote from: SlowOldGuy on April 08, 2011, 05:56:32 PM
There's no starter solenoid on the FJ.  DavidR.

There is on the '86-'87 California model.
Just what are you calling a solenoid?  There is a starter relay, but that's not a solenoid.  The FJ starter works through a starter clutch.  It has no solenoid.

DavidR.

I had to look it up:
http://en.wikipedia.org/wiki/Starter_solenoid

Appears to be semantics we are talking about here.  Seems "Starter Relay" and "Starter Solenoid" are fairly interchangeable.  What they describe as a "Starter Solenoid" on wikipedia (I know - not the most reliable source) sure sounds like what we have on our FJs to me...but I'm not a mechanic or engineer or anything...


Sorta.  The starter solenoid described on the wiki link uses its armature (which has a gear attached to the end of it) to engage the starter bendix (the gear mechanism) to the flywheel.  See the 'electromechanical solenoids' section of this wiki:  http://en.wikipedia.org/wiki/Solenoid   But that's not what is going on with an FJ.

As I understand it, the device on the FJ is a relay... just a high current electrical switch that supplies power to drive the starter motor, which on an FJ doesn't have a Bendix, right?   Though I've never opened one to see what's inside it, that's what Yamaha refers to it as: p/n 36Y-81940-00-00, STARTER RELAY ASSY

Randy T
Indy


Lotsokids

Quote from: racerrad8 on April 09, 2011, 01:20:21 PM
I have never had a bad one, but I have sold & replaced a ton of starters. The early starters use a two magnet system within the starter. That has since been updated to a four magnet system to give the starter more torque.

The other issue is the flow of electricity on the ground side of the starter system. The ground wire from the battery grounds directly to the rear case bolt which must be tight & clean. The issue comes where the starter is mounted to the case with the two tabs. The two tabs on the case a machined bare aluminum.

The starter end plate/mounting tabs on the other hand are painted. The sole source for the starter to ground to the case is reliant on the mounting bolts "digging" in and cleaning some of the paint away to complete the circuit.

I personally clean the paint from the back side of the mounting tabs where they contact the case to ensure the ground side is allowing the full flow of electrical continuity.

If you do that and it still cranks slow, you need to get a new starter as all of the new ones today are the high torque units.

Randy - RPM

Good comments, Randy. But the problem lies with heat. If my bike is cold, it is able to crank repeatedly over and over and over, but usually fires right up. When cold, my starter is very strong. BUT when the bike has been running in the heat... maybe even stop and go traffic in the city or something, if I shut it down, I get an extremely slow crank - maybe just a couple revolutions and that's it. That shouldn't be a ground issue, right?
U.S. Air Force sport bike instructor (initial cadre), 2007-2009

I'm an American living & working in Hungary

indyblue

I could still be bad continuity.  When the starter/engine cases get hot they expand and may cause a poor connection.

I would follow Randy's suggestion and additionally, re-tighten the starter  bolts while it is hot.
Indianapolis, IN `O=o-
1984 FJ1100, 39K mi., custom blue paint, K&N's, jetted, Supertrapps
2005 Pontiac GTO Impulse Blue M6 - gone
2012 Corvette Grand Sport Convertible M6 Crystal Red Tintcoat
1967 Firebird H-O Conv

weymouth399

These starters can have a bad drag.
Check to see if you starter has phillips head or hex head on the long starter bolts.
If it's a phillips head buy a newer style starter.
Old starters have 2 brushes and newer ones have 4.

Bob W
84 FJ 1100
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5  FJ POWERED race cars
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