Spark, Fuel, or other?

[yegg]

So I got the bike back together today to the point where it should start. Yeah, "should" start. You guessed it; no go.

Here is what I know:

The bike cranks steadily but no "catching" sound.
The fuel pump runs.
The plugs have spark (is it good enough?).
The lithium battery is low on charge and it is effing cold in my garage. It is charging overnight.
I double checked all of my connections on the induction module and to the plugs (I'm using coil on plug.)

Is there a way to test to see that fuel is actually making it to the fuel injectors? I have a cold but I swear I thought I smelled fuel.

Is there something else I should be looking at?

Thanks.

 

[s22s]

Outside my pay grade Yegg. Let us know when you figure it out though! Maybe someone else can help...good luck.

#ridesomemore

 

[yegg]

Update:

Starter fluid directly into the induction module did not start the bike.

To me this sounds like a lack of spark. But I was able to get spark when out of the cylinder head and grounded to the motor.


Sent from my iPhone using Tapatalk

 

[yegg]

Update:

I replaced the crankshaft position sensor. That did not help.

I replaced the coil on plug with the original coil and plug wires. They were removed for aesthetics, not performance. That did not help.

After the above two changes I also tried using starter fluid again. Nothing.

According to my FP3 there are no fault codes.

The bike cranks well but does not catch.

I honestly have no idea what to check next. Any ideas?

Thanks.

 

[yegg]

Morning update.

Just for fun I tried firing her up again this morning. I turned the bike on, heard the pump run, and then hit the start button while holding the throttle open as well. I did not let up on the starter button.

It cranked well, then there were two loud backfires and a mini ball of flame shot out of the tailpipe connected to the front cylinder. Another noise I heard, and this is the only way I can describe it, is a very loud hollow bubble pop noise.

Any ideas?

Thanks

 

[yegg]

Afternoon Update:

I purchased a cheap Harbor Freight inline spark plug tester and verified that I do have spark.

The neutral switch was one suggestion that I received. I can crank the bike in neutral. If I shift out of neutral the bike will NOT crank unless the clutch handle is pulled in. To me that indicates a properly functioning neutral switch.

Someone has got to have an idea.

Thanks.

 

[hulkss]

Just to make sure everything is together right, do a cranking compression check.

I do it this way:

Spark plugs out
Trans in neutral
Compression gauge connected to a spark plug hole
Stick a screwdriver handle in the throttle to hold it part way open
Leave everything switched off
Use a manual push button starting switch to crank the bike (no fuel or spark this way)
Crank a few seconds 'till the gauge peaks
Should be around 200 psi
Then do the other cylinder

It's good info to have for reference even if it does not help your problem.

A compression tester gauge has a check valve to hold the peak pressure it gets.

 

[yegg]

Thanks Hulkss.

What is a manual push button starting switch? I think I have the concept, but what do you use and where are you connecting it?

I went ahead and pulled the induction module before dinner and my plan is to clean the injectors too. I got lucky as a friend worked on his bike recently and I found an old injector connector in my garage. I’m going to use that and a 9 volt battery to cycle it while running a cleaner through it.

When I pulled the induction module I noticed a black oily residue in it. I wiped it clean but I’m wondering about that now.

Do you have a recommendation for a decent compression tester?

Thanks.


Sent from my iPhone using Tapatalk

 

[hulkss]

Thanks Hulkss.

What is a manual push button starting switch? I think I have the concept, but what do you use and where are you connecting it?

I went ahead and pulled the induction module before dinner and my plan is to clean the injectors too. I got lucky as a friend worked on his bike recently and I found an old injector connector in my garage. I’m going to use that and a 9 volt battery to cycle it while running a cleaner through it.

When I pulled the induction module I noticed a black oily residue in it. I wiped it clean but I’m wondering about that now.

Do you have a recommendation for a decent compression tester?

Thanks.


Sent from my iPhone using Tapatalk

Remote Starter Switch

It goes between the battery positive post (can be the starter big positive post) and the little post on the starter that powers the solenoid.

Compression Tester

 

[yegg]

Thanks again. I owe you a dinner if you ever get out my way.

I ordered both items and they should be here by the end of the week if UPS ever decides they can make kit up my mountain again.


Sent from my iPhone using Tapatalk

 

[yegg]

Spark, Fuel, or other?

Ok, so here is what happened with the compression test. At first I couldn’t get anything more than 30psi per cylinder. Then after repeating the test many times I got the rear cylinder to about 130. The front I am not able to get past 60.

The air cleaner is off and the butterfly valve is about a third open when doing the test.

I just tried again (this is the edit) several hours later and could not get the front past 30 and the rear past 60.

Any ideas of what this might mean as is? As far as I can tell it indicates a problem with either my piston rings or my valves. Is there a troubleshooting flow chart? How does one troubleshoot the valves? I mean I lapped the valves and verified they held water during the cleaning process and did not let light through when shut.


Sent from my iPhone using Tapatalk

 

[hulkss]

I can't recall what all you did to the bike. If the cams were out you may have the cam timing off. You could have the push rods in the wrong locations or adjusted to the wrong length.

I would guess the valves are not working properly. The piston rings should work better than that even if broken or upside down I would think.

If the cam timing is off you may have bent the valves with the pistons and now they don't close properly.

 

[yegg]

Cams did not come out. I pulled everything down to the crankcase. Replaced the piston rings, cleaned the pistons, cleaned the valves and cylinder heads, and replaced the valve stems.

Where do you suggest I look based on that?


Sent from my iPhone using Tapatalk

 

[hulkss]

Any chance the pistons are in the wrong hole or backwards so the valve cutouts are out of place? Compression releases are ok? Proper thickness head and base gaskets? Again, the push rods are not all the same length.

Did you run a flex hone in the cylinders or use new cylinders?

 

[yegg]

Any chance the pistons are in the wrong hole or backwards so the valve cutouts are out of place? Compression releases are ok? Proper thickness head and base gaskets? Again, the push rods are not all the same length.

Did you run a flex hone in the cylinders or use new cylinders?

I’ve gone ahead and ordered a leak down tester to do further diagnostics.

OTC 5609 Cylinder Leakage Tester Kit https://www.amazon.com/dp/B0030EVL60/ref=cm_sw_r_cp_api_glt_fabc_VMMB4AYPPCJ0DD66RYPY

Using the leak down tester should tell me if air is escaping through a valve and if so which one. I am trying to figure out where the air would come out of it is being routed down past the piston rings. Any help on where to look for that scenario?

I have the electronic automatic compression releases. Both solenoids were retracted, so closed, when installed. I guess I can pull them back out and put voltage to them to see if they fire. Is that what you mean?

Ok, I went and double checked my service manual and now you have me wondering. I don’t have a cylinder base gasket. The bottom of the cylinder only has an O ring. Am I missing something? There is a cylinder head gasket and I have a stock 103 so that should just be one gasket per cylinder that is sandwiched between the top of the cylinder and the bottom of the cylinder head.

As for push rods, there should be two lengths, correct? The short ones are the intake and the long ones are the exhaust.

I used the existing cylinders as they were in excellent shape (measured at a machine shop) and even had a lot of original cross hatching still showing. The dealer did not have new rings but sold me a pair of take off pistons with rings that came off a floor bike that went straight to upgrading when purchased.

Thanks.


Sent from my iPhone using Tapatalk

 

[hulkss]

When doing the leak down test, get some tubing and plastic barb fittings as needed and connect the cylinder head vents or lines to a balloon. If the the balloon inflates, that's where the air is going (have your drain plugs and filler cap in place).

Sounds like your compression releases are fine.

Some engines have base gaskets, some use o-rings, you are fine.

Sounds like you still have a mystery to solve.

 

[yegg]

Dumb question of the day. I can do a leak down test with the rocker box covers off can’t I?


Sent from my iPhone using Tapatalk

 

[hulkss]

Sure, any air leakage past the piston rings will go out the rocker boxes via the push rod tubes and drain passages. So, don't bother with a balloon on the vents.

 

[yegg]

The reason I asked is that I am having a hell of a time turning my rear wheel even in sixth gear and I want to crack the rocker box covers to make sure I am on TDC with both valves closed.

I am also thinking I have some kind of valve related issue as it is so damn hard to turn that rear wheel. I have absolutely no idea what I may have done wrong on reassembly.

Sunday i have a buddy coming over to give me a hand and keep me from imbedding any more wrenches in the garage wall.

Thanks.


Sent from my iPhone using Tapatalk

 

[hulkss]

I would guess maybe a piston is backwards or in the wrong cylinder. It would then interfere with a valve.