Raptor Forum banner

Another wont start....

5K views 62 replies 6 participants last post by  willykiller 
#1 ·
I just gone done doing an entire motor rebuild and i went to go fire it up but something with the relay or battery is messed up. All the wiring is correct, but heres the dilemma... I charged the battery all night, and it will crank over, but only 1 "pulse" or turn over at a time then the relay will start clicking. I even tried jumping it with a car and then disconnecting the battery all together and hooking up the jumper cables to the positve and negative wires and it still only goes at one pulse at a time. The bike fired up once so i know it runs but its just something with the starter or relay or the battery. What could it be????
 
#6 ·
Check your positive cable at the starter motor. Use a voltmeter, or a multimeter set to volts. You wanna check it while cracking and make sure that you are getting at least 12 volts. If that's good, then try removing your spark plug and turn your motor over by hand. To do so, remove the circle plug on the middle of the left side cover. Put a socket on the crankshaft and turn counterclockwise. Should turn over relatively easy with spark plug removed.
 
#13 ·
That is not what I asked you to do, hook the jumpers to the starter main lug and to the ground at the base of the starter, avoid all raptor stock wiring, see if the engine turns over................
Im saying I did that before...
Im sorry, but what do you mean the starter main lug and to ground at the base of starter? That actual starter motor?
 
#14 ·
Im saying I did that before...
Im sorry, but what do you mean the starter main lug and to ground at the base of starter? That actual starter motor?
The starter base is the frame of the starter, the main lug is the bolt where you attach the positive cable that comes from the starter solenoid.............
This bypasses all electrical wiring, switches and relays...........
 
#18 ·
Okay, just got out of the garage...
Well come to find out, all the wiring was good and all the grounds and contacts were clean. (I went over them twice just to double check) I pulled the starter gear off the starter motor gear, and the starter motor will keep spinning with no problems what so ever when i hit the starter button. I removed the spark plug from the motor and the motor turned over a few times before the solenoid buzzed out. So im thinking its a bad battery or my decompression on the cam isnt working properly? I also just read on another thread that something with the valve clearance could be messed up? I just adjusted the valves but could that be a possible problem?? The snow is coming tomorrow and I wanna go riding! :)
 
#23 ·
one jumper to the cable lug on the starter's body, other to case anywhere near the starter or to the rear of the starter where it bolts down to the case will suffice.
 
#24 ·
Well i jsut went out and bought a brand new battery. I slapped it in and hit the starter button. This is installed with both my old and brand new battery- I hit the starter and it will turn over, however at what seems to be like one revolution of the motor. When i remove the spark plug, it turns over as it should. Is the decompression mechanism not working properly?
 
#26 ·
If it turns over one turn and stops, you may have too much compression, this could be caused by your build or your decompressor not working, the decompressor needs to be assemble properly and it relies also on the proper valve lash...............
 
#32 ·
Valve lash is the same as valve clearance... Did someone help you rebuild you motor?? Because it sounds like you have no idea what your doing... your lack of knowledge make me think you missed a number of crucial steps in rebuilding your motor...

On another note, did you do a stock motor rebuild... I would pull your starter and have it professionally tested. Just because your starter will turn you motor over with no compression(spark plug out) doesn't mean your starter is creating enough torque to turn a healthy, freshly rebuilt motor with excellent compression. The insulation on the starter windings may be burnt up cause your weak cranking.
 
#33 ·
I rebuilt my motor and i do know what im doing. Im no newb to motors, ive rebuilt many 2 stroke motors before and a handful of four stroke motors, but your guys terms you use make me ???
its a stock motor rebuilt. it was just rebuilt with a hot rods complete crank and connecting rod, all new bearings and seals, valve seals, valves, and valve guides. Im just stumbled about the starter motor because it worked fine before the teardown :wow:
Should i check the valve clearance again?
 
#34 ·
Yes, check valve clearance. I agree with the rest - if one has experience with rebuilding, one usually understands the common terms... with your lack of 4-stroke experience, I understand why some of this may be new. However, a good read of the manual should overcome that issue.
 
#35 ·
Im only 17 guys, give me a break! Lol.
I do know engines, but know way more 2 stroke than 4 stroke. I built the motor with my dad and hes knows a great amount about motors but hes currently out of state for business. We rebuilt the motor using the manual and help from the dealer. We had the valves cut, installed and what not by the dealer. What im thinking it is now is i have to readjust the valves, and or the cam decompression isnt working. When i was putting the cam in, i made sure the decompression was working and the pin in the cam was working smoothly. I just took off all the plastics and gas tank. Im going to check the valve clearance and try again. If that doesnt work, ill pull the head off and inspect.
Question:???
When i put a ratchet to the flywheel side, (on the nut on crank) should i be able crank the motor somewhat easily without waiting for the decompression to release? Im guessing yes? and thats my problem?
 
#36 ·
I can turn my bike's engine over with 3/8 ratchet with about an 8in handle without too much trouble (that's with the spark plug in). The decomp is disengaged by centrifugal force. The starter motor doesn't spin the cam fast enough to disengage the decomp mechanism. This is why you can turn your motor over fairly easily by hand. Once the motor starts, the cam spins much faster and decomp goes away and the motor will build full compression. If your decomp isn't releasing compression, then your starter will have a much tougher time turning your motor over... So you don't need to "wait for the decompression to release" its released if the motor ain't on or its not working properly...
 
#39 ·
Willy may have some ideas, but typically, this calls for new/used head and head cover (they are a matched set), sorry. The real question is as to how this happened? You don't want a repeat.
 
#40 ·
Thats not really what i wanted to hear :mad:
Its not torn up too bad at all. Possibly bring it to a machine shop and get it cleaned up ? :eek:

On the sprocket side of the cam, i believe the timing chain tensioner was putting way to much tension on the chain on that side, making it dig into the head.
 
#41 · (Edited)
On the sprocket side of the cam, i believe the timing chain tensioner was putting way to much tension on the chain on that side, making it dig into the head
That usually means that the tensioner was installed with the center bolt and spring already in the tensioner... The tensioner ratchets out to full travel due to the spring and center bolt, and then cranks way down on the chain as it is tightend to the case.

This would also make the engine very tight and hard to turn over (your initial symptom).

Did you do the valve job yourself or have it done?
 
#43 ·
Did they install the tensioner? If so, you should have some recourse...

Unfortunately, if you installed it, chalk it up to learning! If I had a dime for everytime I've had to learn that way...
 
#57 ·
Think Plastigage would work here, for the measurement, Willy?
It should, when I did use it, I measured the stuff two ways, one by comparing the squashed plastic gauge with the gauge on the envelope and I also measured the thickness of the plastic gauge after it was squashed...........
 
#61 ·
Well guys got my new cam installed. Started right up. I didnt actually "shave" down the head cover and cylinder head, i just lightly smoothed out the burs that the old cam made. It runs great! Theres a small tick (just gotta readjust the exhaust valves) but there a stumble on lift off. If I remember right, it always use to do it, but i just want it gone. When I pull in the clutch and shift, i take off fine, then it will stumble like its struggling for fuel or air? Could it be jetting, dirty carbs, or my air filter? Thanks-Brett
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top