Raptor Forum banner

1 - 20 of 27 Posts

·
Registered
Joined
·
59 Posts
Discussion Starter #1
I have just pulled my 686 Raptor engine back apart to replace a head gasket that blew out last July. It has been sitting up in the shop since then. I got it all torn down, replaced what needed to be replaced, got it re-assembled, charged the battery and tried to fire it off so i could fill the oil tank. Well it would spin the engine over once or twice and the solenoid would start buzzing. Well i assumed it was the battery that went bad. So i charged another battery that i had sitting around, same thing. I even went and bought another brand new battery to try, and no suprise, same thing. I pulled the spark plug out of the hole and tried to turn it over, and it still was spinning very slow, maybe 1 revolution/second. I have had this problem before with a different quad, and a good cleaning of the starter resolved my problem. I cleaned the starter last night and stuck it back in, and its still the same thing. Does this sound like i need to replace the starter or do i need to try anymore tests to be sure?

Voltage at the starter while cranking = Between 5-8 vdc

Voltage at the relay while cranking = between 5-8 vdc

Battery voltage (Not cranking) = 12.8 vdc

The engine is not overly difficult to turn over, its the same as it always has been. I just wanted to check with some of you before i go out and waste more money on this thing.

Thanks, Richard
 

·
Master of the Electron
Joined
·
15,074 Posts
The important measurement you left out is battery voltage WHILE cranking - if it's also at 5-8 volts, it has a problem... it it's higher, you have a bad cable or connection to the battery.

What happens when you jump it to a known good auto battery?
 

·
I am unique
Joined
·
22,621 Posts
He has stated 5-8 volts while cranking, which suggests a bad battery, try boosting with a car, you could even hook the booster cables direct to the starter to bypass most of the electrics....................
 

·
I am unique
Joined
·
22,621 Posts
I've tried off two different running vehicles, just super slow cranking..
Judging by what you are saying, I would suspect starter problems or engine problems...........
 

·
Registered
Joined
·
59 Posts
Discussion Starter #6
I'm gonna double check all the connections, and in through the starter again tonight. I'm suspect me the starter though, because when I got the bike the starter was disassembled and something is probably not right with it.
 

·
Master of the Electron
Joined
·
15,074 Posts
He has stated 5-8 volts while cranking, which suggests a bad battery, try boosting with a car, you could even hook the booster cables direct to the starter to bypass most of the electrics....................
Where did you see that, Willy?

I see:

Voltage at the starter while cranking = Between 5-8 vdc

Voltage at the relay while cranking = between 5-8 vdc

Battery voltage (Not cranking) = 12.8 vdc

Nowhere do I see battery voltage WHILE cranking, which is now the most telling measurement. This could simply be a bad cable between battery and solenoid. Measurement of battery voltage WHILE cranking will tell us.
 

·
I am unique
Joined
·
22,621 Posts
Where did you see that, Willy?

I see:

Voltage at the starter while cranking = Between 5-8 vdc

Voltage at the relay while cranking = between 5-8 vdc

Battery voltage (Not cranking) = 12.8 vdc

Nowhere do I see battery voltage WHILE cranking, which is now the most telling measurement. This could simply be a bad cable between battery and solenoid. Measurement of battery voltage WHILE cranking will tell us.
Voltage at the solenoid is indicative of battery voltage............
 

·
Registered
Joined
·
59 Posts
Discussion Starter #9
Battery voltage is the same, that wire has no resistance.

I just re tested everything, checked grounds, cleaned the starter, checked continuity, bypassed the relay, and whatever else I could think of. I think the starter is not functioning correctly. When I bought this bike it was in 1000 pieces, and the starter was disassembled in a box. The brushes don't look perfect, and where the shaft of the starter goes into the end piece on the mount side is a little roughed up. Is there supposed to be any kind of bearing on that end, cause there's not?
 

·
Master of the Electron
Joined
·
15,074 Posts
Voltage at the solenoid is indicative of battery voltage............
Willy, you've never had or seen a bad supply cable from battery to solenoid?

Battery voltage is the same, that wire has no resistance.
ABSOLUTELY NOT the case if that cable itself is the problem (which is quite common). Battery acid wicks up into the crimp lug at the battery side, corrodes the copper which either becomes brittle and breaks or just makes terrible connection with the crimp... if you don't measure AT the battery, this important piece is left out, so 5-8 VDC at the solenoid does NOT tell us if the drop is at (or in) the battery or across that cable. EVERY piece of wire/cable has resistance, the question is how much? If overly high (due to the damage described above) this cable can be your culprit.

Have you measured voltage directly at the battery while cranking the starter? It is a very simple, quick test to verify that the supply cable is not your issue. If you haven't, then anything you do to go forward is simply due to assumption, not fact.

The starter shaft just rides in bushings - one in the rear end plate and the other at the front plate where the shaft protrudes and goes to the gear. The gear end rides in a bushing in cover. If the brushes are bad, it is possible for the starter to draw excessive stall current and to turn very slowly - cleaning the commutator and brush faces may help. A good cleaning and light lubing of the bushings and shaft contact surfaces, can also help, if they are dry and rough.
 

·
Registered
Joined
·
59 Posts
Discussion Starter #12
I understand what you are saying, battery voltage is also around 7 or 8 vdc while cranking. Even with jumper cables directly to the starter it won't spin it fast enough to crank it. This is weird because it worked fine a few months ago. And I was turning the engine over easily by hand with an 8 inch ratchet.
 

·
Master of the Electron
Joined
·
15,074 Posts
Okay, so you DID measure battery voltage directly... and drop was similar. FYI With no load, the starter draws very little current, so the drop across a cable with excess resistance will ALSO be much lower than it will be when the starter is under load.

How did you connect 'jumper cables directly to the starter'? What battery did you use? How were jumpers connected?

If, when cranking, you see a near same voltage at the battery, both sides of the solenoid and at the starter, (and the voltage is somewhat low, as in your case), then either the battery is bad (which you should have disproved by jumping to a known good auto battery), or the starter motor is drawing way too much current... why? Either the starter is bad, or it is being held from turning quickly by an engine that is somehow tight. What happens when you remove the starter from the bike (or remove the intermediate gear from the side case)? Does the starter now turn quickly or still slow? (is this what you described as 'no load'?

If still turning slow, it's either the starter's brushes, bushings or both. If fast, either the engine is tight (try turning with ratchet on crank bolt), ir the gearing connecting the starter to the one-way is binding... do you have all 3 hollow locating pins in the left side cover? Any of these missing can cause the side cover to be mis-aligned, binding the starter gears.
 

·
Registered
Joined
·
59 Posts
Discussion Starter #15
Okay, so you DID measure battery voltage directly... and drop was similar. FYI With no load, the starter draws very little current, so the drop across a cable with excess resistance will ALSO be much lower than it will be when the starter is under load.

How did you connect 'jumper cables directly to the starter'? What battery did you use? How were jumpers connected?

If, when cranking, you see a near same voltage at the battery, both sides of the solenoid and at the starter, (and the voltage is somewhat low, as in your case), then either the battery is bad (which you should have disproved by jumping to a known good auto battery), or the starter motor is drawing way too much current... why? Either the starter is bad, or it is being held from turning quickly by an engine that is somehow tight. What happens when you remove the starter from the bike (or remove the intermediate gear from the side case)? Does the starter now turn quickly or still slow? (is this what you described as 'no load'?

If still turning slow, it's either the starter's brushes, bushings or both. If fast, either the engine is tight (try turning with ratchet on crank bolt), ir the gearing connecting the starter to the one-way is binding... do you have all 3 hollow locating pins in the left side cover? Any of these missing can cause the side cover to be mis-aligned, binding the starter gears.

I connected the jumper cables from a running automobile with a good charging system, to the starter. Ground to the bolts that hold it to the cases, and positive to the (+) post coming off the body off the starter. It turns slowly just the same as without jumper cables.

With no load on the starter (intermediate gears between starter and one-way removed), it spins smooth and fast.

I can put a small 8" ratchet with a socket on the crank nut and spin it by hand with no more effort than normal.

Yes all the locating dowels are in the LH side case, i acutally just put a new stator in it and double checked everything.

I will try and double check once again that everything is correctly alligned and not binding.

I'm to the point of assuming its the starter, because i feel like i have tried everything else. Do you know how much current the starter should be drawing under load and not under load?
 

·
Master of the Electron
Joined
·
15,074 Posts
I agree that all is pointing to the starter now.

Unfortunately, I have never measured current used by a properly working Rappy starter - perhaps someone else has a valid measurement?

When I first got my quad, the starter was very sluggish - both under load and not... I removed and rebuilt it, and it was fine on the bench. When I re-installed, it was sluggish again. I finally resolved the issue by removing the mounting bolts again, and moving the starter around to 'seat' the nose properly - the o-ring around the nose must have distorted and unseated slightly when I installed the starter, causing the gears to bind; and moving the starter around, vigorously, properly seated the o-ring... may not be your issue, but just another thing to check, since you have removed the side cover that engages that o-ring.
 

·
Registered
Joined
·
59 Posts
Discussion Starter #18
I understand what you are saying, but have not come across an o-ring? Like i said i bought this bike completely dis-assembled in a bucket, so i could be missing somethings here and there. I was suspect of this starter when i first installed it, but it worked fine for a few months.

I called for the heck of it to price a starter from Yamaha (not going through them for parts), they wanted $399 for a starter!!!!!!!!!!!!!!

I am fairly familiar with electronics, but not extensively. I just can't put my finger on the problem with the starter, and i guess i will try and find a known working used one and see if that changes anything.

But, first i will try moving it around like you said.

Thank, Richard
 

·
Master of the Electron
Joined
·
15,074 Posts
THere is an o-ring groove around the nose of the starter, the 0-ring (#3 in drawing) fits into this groove and when the starter is inserted into the bore in the side cover the o-ring seals and locates the nose and the output shaft. If necessary, there are lots of starters on eBay for reasonable prices.
 

Attachments

·
Registered
Joined
·
59 Posts
Discussion Starter #20
See here is what i had to start with for $700.. Haha, i felt like taking on a project, and quite the project it has turned into!!!!!!!!!





I will check the o-ring that you speak of, because i do not remember seeing it.
 
1 - 20 of 27 Posts
Top