Epic Fail :(

[davem222]

Hey guys,
So I got my newly rebuilt xs all wired up and went to kick it, nothing. I re-did everything on the bike myself (except rebuilding the bottom end) and thought "well, I probably screwed something up. I checked the float heights, good, I checked the carbs cleanliness, good (I am running mikes xs filters on it now instead of stock as well as mikes 2-1 exhaust and have not rejetted). I checked for spark, got it, and then did a compression test. Not so good. Like 100 on each and that's after 8 or 10 kicks. I'm a novice, and this is only my second top end rebuild. Anyone have any thoughts? Maybe there are some "usual suspects" that I'm not thinking of? I can smell gas in the spark plug holes and out the exhaust (just the faintest whif of it). If anyone has any thoughts, I'd appreciate the insight. Thanks.

Dave

 

[davem222]

PS: running Hugh's PMA and Pamco, could I have possibly screwed up the TDC timing royally? I haven't done any Pamco timing because I haven't gotten it running yet, could that be the issue?

 

[scabber]

You could have screwed something up or not. TDC on the compression stroke ? Pamco set up as per instructions. Check and double check.

 

[apt3customs]

Even with most basic settings off it should still run super crappy at least. got spark? if so, then got spark when fuel is being compressed? sounds like you have fuel... id double check your wiring possibly. good luck.

 

[GreasyC]

You are holding the throttle open during that compression test right? If so you have major problems there.

 

[yamaman]

you need to check your valve timing is right, if it is, check your valve adjustment again. Could be a reason for such a low comp reading. Ive never done a comp check on a new build, not sure how low it should be, but id reckon more than that!

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[davem222]

You know what? I wasn't holding the throttle open during the comp test. Plus my compression gauge is old and possibly crappy. I DID get it running for about 30 seconds on my 8 billionth kick though lol. Don't know if that means anything, gonna do a compression test with the throttle open once I cool down from all that kicking

 

[davem222]

Here's a question, I have the wiring mocked up and kinda hanging from the frame w/ zip ties. Does the reg/rect have to be grounded to the frame? I have the ground wire attached to the neg (black) terminal on the battery circuit, but do I need to physically ground the case of the reg/rect?

 

[kvanderploeg]

Set the bike to what you have marked as TDC and look in one of the spark plug holes with a flashlight to be sure you see the top of the piston.

Kent

 

[davem222]

Yeah, TDC is top of the left side piston. I'm going to get a new comp gauge today after work, see if it was my gauge. Also, going to attach the neg bat terminal to the frame, I only had everything hooked up to "ground" ie: the neg bat terminal before, perhaps a frame ground is what I need? Also going to run through the entire rigamarol (sp?) again, cam chain tension, valve clearances, etc. Fingers crossed. Like I said, I did get it running for a brief moment yesterday and the sound was sweet....for about 15 seconds

Dave

 

[Phail]

Also, going to attach the neg bat terminal to the frame, I only had everything hooked up to "ground" ie: the neg bat terminal before, perhaps a frame ground is what I need?
Dave

Well, there's your problem.

Yes, you need to ground to the frame/engine so the spark plugs are grounded, coil is grounded. So, yes, you need to connect the neg of the battery to the frame.

 

[davem222]

Ahahahahahahahah!!! Well headed out back armed w/ a new compression gauge and a new knowledge of a) my own foolishness and b) an even deeper appreciation for you guys. Lets see how this goes...

 

[davem222]

Hmm, so re-checked the compression w/ throttle open and the new comp gauge, about 120 on each side, so that's good. Then I grounded the neg battery terminal to the little screw on the top of the bottom end of the engine (right next to the cam chain tensioner adjuster). All of my "grounding" needs are wired into this grounded wire and the neg bat terminal, so I figure this should be ok, yes? nope....nothing, lol. I even tried hooking up the 12.7V 7aH battery I have and the sparx capacitor I got alternatively but STILL nothing. I then took out the plugs and rotated the engine around while grounding one at a time on the side of the engine case: no spark. I know there's gas because I can smell it, so I'm guessing my prob is that I have no spark. Don't really know what to do as everything as best as I can tell is hooked up according to the diagram. Anyone have any thoughts? Bear in mind that I've only hooked up the ignition circuit here, no lights or anything.

 

[davem222]

Also, I'm using the 14-0901 pamco/coil kit from Mikes w the 5K resistor plugs and I am using 2 BP7ES plugs, would the plugs possibly be the problem? Should I have resistor plugs or something?

 

[yamaman]

You mean 5k caps I think? No, resistor caps or plugs, not both. You may have fried the coil with your earthing issues. Check resistance accross the 2 small wires and accross the 2 plug wires. Hope I'm wrong, cheers

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[davem222]

Yikes. I hope you're wrong as well, but I'll check. What should the resistance measurements be for these? By the "two small wires" I assume you mean the coil wires yes? And for the 2 plug wires you mean resistance between one plug wire and the other?

 

[davem222]

So the resistance between the coil wires is 6 Ohms and between the plug wires is 26k ohms, but I don't really know what they should be lol.

 

[davem222]

Oh and yes I meant resistor caps. Lol whoops.

 

[XSLeo]

The two small wires are the ones that hook to power and the Pamco. In your diagram the red and orange wires. Should be 2.5 ohms. Infinity to the plug wires and metal mounts. The plug wires I'm not sure on the ohms, probably some where around 20k ohms. Infinity to the primary side and the metal mounts.
In your diagram the black wire from the Pamco can hook to the frame. The black wire from the reg/rec needs to go to both the battery and cap negitive and the frame.
Electricity needs to travel in a circle, from the battery out to what you want to run then back to the battery. With the Pamco grounded to the frame you need the battery grounded to the frame to complete the circle.
Circle is where the word circuit comes from.
Leo

 

[davem222]

Thanks Leo. Well, it's 26k ohms plug to plug like I said, and about 6 between the two coil wires although I'm starting to doubt the accuracy of my cheap harbor freight multimeter since when I short the two test leads it tells me the resistance (which should be zero) is 1.6 ohms. Sigh. So it SEEMS like the coil is ok, no? But still no spark. From coil leads to motor mount is infinity (although is there some sort of stand-off I should have on the coil? I basically have it fastened to the frame w metal u- brackets through the mount holes.) Quick question: I have all of my ground hooked up on one line, battery neg terminal to ground and that same wire to all other grounds. Should there be separate grounds perhaps?