Electric Starter issue / Compression test

[acebars]

Hello, merry christmas!

Right just got better after a year of being sick

So just came to look at the TX650 '73 I bought months ago, first time I've ever worked on an XS and having only rebuilt one bike before I'm still fairly green at mechanics.

Carbs need a clean so doesn't start yet, pulled them off.

Thought I'd do a compression test with the electric start.

Trouble is the electric starter does not move the crank in neutral (and there is no neutral light), but it does engage when the bike is in gear and the bike surges forward, pulling in the clutch didn't seem to help either and I nearly ended up with the bike on top of me!

Anyone any ideas?

(I also can't seem to get a proper compression test with the kick starter, I've only ever used an electric starter to find this )

 

[deadchef]

couple things...

1. stock wiring won't allow for the starter to engage while in gear, only in neutral. sounds like you need to address the wiring.

2. you can get reliable compression results from kicking. basically kick until the needle doesn't go any higher. put it in neutral and start kicking. don't pull in the clutch.

3. not sure what tester you are using but the best ones will screw into the spark plug hole. also, make sure you have the throttle wide open for best results.

 

[acebars]

2. you can get reliable compression results from kicking. basically kick until the needle doesn't go any higher. put it in neutral and start kicking. don't pull in the clutch.

3. not sure what tester you are using but the best ones will screw into the spark plug hole. also, make sure you have the throttle wide open for best results.

Um yea, I have a proper gunson screw in one.

I've never ever managed to get a proper result kicking, on my CB500t kicking cold got 80 Psi, finally mounted the electric start and got 155Psi on average. I've got 80 Psi on the XS650 kicking.

1. stock wiring won't allow for the starter to engage while in gear, only in neutral. sounds like you need to address the wiring.

Electrical Gremlins EEK! Any idea where I should start?

 

[deadchef]

well a warm engine will produce better compression results. kicking sure isn't the quickest or easiest but i've done it and it can work.

for the electrical issues i would start out looking at some of the schematics here.
http://www.xs650.com/forum/showthread.php?t=61

this is also a great thread that explains what (should) happen when you turn the key.
http://www.xs650.com/forum/showthread.php?t=9625

it can be difficult to diagnose electrical gremlins through an internet forum. best thing to do is get intimate with your wiring setup and go through each 'system' to find the fault. do you have a volt meter?

could you give some more specifics on your bike, ie. ignition, wiring setup, etc.?

 

[acebars]

it can be difficult to diagnose electrical gremlins through an internet forum. best thing to do is get intimate with your wiring setup and go through each 'system' to find the fault. do you have a volt meter?

could you give some more specifics on your bike, ie. ignition, wiring setup, etc.?

Err trouble is I don't know what it's all meant to look like and I've only just started looking at it. Thanks for those posts will begin reading.

Removed the clutch cable off the lever, and tried to take the chrome clutch adjuster nut cover off.... No idea how on earth that is meant to come off.

Then I'll be taking off the left case cover and going from there..

Need to get the correct 5mm hex head for my power drill as I've just snapped two keys trying to undo the nuts by hand on the left cover!

well a warm engine will produce better compression results. kicking sure isn't the quickest or easiest but i've done it and it can work.

I can never get it to work! Don't know if it's not because I can't kick through hard enough, although I can kickstart a bike.

 

[deadchef]

the chrome cover to the adjuster nut will pry off. if you look at the cover dead on there is a slight recess at 6 o'clock, just big enough for a flat blade screwdriver to pop it off. be gentle, no reason to get tough with it otherwise you can mar the surface of the aluminum cover.

a coat of anti-seize on the threads of the side cover allen screws will help them release in the future. on my bike they seem to snug up after a few miles so they only get lightly torqued.

 

[acebars]

Right managed to pop that chrome cover off.

Adjusted the clutch, and when I hit the electric starter it engaged the crank in neutral, great I thought, but by the time I took the spark plugs off, unplugged the carb boots and put the compression tester on it decided to revert to it's previous behaviour.

Put some better shoes on and did another dry compression test, 100psi both sides, but I don't believe that's the correct result as I had 80psi by foot on the CB500t I built which almost doubled on electric start.

When I tightened the clutch at the lever more, the crank was not even spinning when I kickstarted, when in gear pulling in the clutch had no effect and the bike still shuddered forward, so that leads me to believe that is a clutch problem and neutral light issue also, will have a look at it tomorrow again.

 

[XSLeo]

Is the compression reading the same on both sides? Within 10%? If so then your ok for now. If your bike has been setting for more than a few years the compression can be low. Once you get it running the compression will come up as the engine goes through a new break in.
As an engine sits a thin layer of rust can build up on the rings and cylinders as well as valve stems. This prevents a perfect seal on the combustion chamber. Once you get it running this rust wears away quickly, then you get a better seal and the reading comes up. Many have reported less compression but after a few hundred miles it come up to around 150 psi.
I might suggest making some very good penetrating fluid by mixing Acetone and AFT at a 50-50 mix. Put in a pump lever oil can shoot some into the plug holes and remove the valve adjuster covers and shoot some around the valves. With the carbs off turn the engine so the intake valves are open and shoot some above the valves. The same on the exhaust if you want to pull the exhaust head pipes.
This will cut through the rust and help loosen sticky rings and valves.
On the 73 there is no electrical devices to prevent the starter from working in neutral. That wasn't added till 80 something.
With the bike in neutral the starter should work just fine. What I might suggest for now is to use a spare car battery and a set of jumper cables. Hook them up to the battery or hook from the spare to a good frame ground on the black, the red put a large screw driver in the clamp. Now at the starter relay find the cable that leads to the starter, touch the screwdriver to the cable. This bypasses all the electrical systems and cranks the starter. You don't even need the bikes key on.
Leo

 

[acebars]

Is the compression reading the same on both sides? Within 10%? If so then your ok for now. If your bike has been setting for more than a few years the compression can be low. Once you get it running the compression will come up as the engine goes through a new break in.

As an engine sits a thin layer of rust can build up on the rings and cylinders as well as valve stems. This prevents a perfect seal on the combustion chamber. Once you get it running this rust wears away quickly, then you get a better seal and the reading comes up. Many have reported less compression but after a few hundred miles it come up to around 150 psi.

Thanks for the pointers Leo much appreciated. Yes dead on 100psi on both sides, and yes the bike has been stood for years, only has 6000 miles.

I might suggest making some very good penetrating fluid by mixing Acetone and AFT at a 50-50 mix. Put in a pump lever oil can shoot some into the plug holes and remove the valve adjuster covers and shoot some around the valves. With the carbs off turn the engine so the intake valves are open and shoot some above the valves. The same on the exhaust if you want to pull the exhaust head pipes. This will cut through the rust and help loosen sticky rings and valves.

Thank you! Great advice (by AFT did you mean to write ATF) I actually have some Plus gas penetrating fluid so can I just use that instead of the acetone/ATF mix (I do have both of those as well)?

On the 73 there is no electrical devices to prevent the starter from working in neutral. That wasn't added till 80 something.
With the bike in neutral the starter should work just fine. What I might suggest for now is to use a spare car battery and a set of jumper cables. Hook them up to the battery or hook from the spare to a good frame ground on the black, the red put a large screw driver in the clamp. Now at the starter relay find the cable that leads to the starter, touch the screwdriver to the cable. This bypasses all the electrical systems and cranks the starter. You don't even need the bikes key on.
Leo

Yes good idea Leo, the thing is the electric starter does work. The problem I am having is it engages and spins but will not crank the bike when in neutral it only seems to crank the bike when in gear pulling the bike forward. Pulling the clutch in has no effect (to stop the bike surging forward) despite my having tried to adjust it.

Going to get the left case cover off to have a look at the clutch lever when the shops open and I can get the right bit for the bolts.

 

[retiredgentleman]

Thanks for the pointers Leo much appreciated. Yes dead on 100psi on both sides, and yes the bike has been stood for years, only has 6000 miles.



Thank you! Great advice (by AFT did you mean to write ATF) I actually have some Plus gas penetrating fluid so can I just use that instead of the acetone/ATF mix (I do have both of those as well)?



Yes good idea Leo, the thing is the electric starter does work. The problem I am having is it engages and spins but will not crank the bike when in neutral it only seems to crank the bike when in gear pulling the bike forward. Pulling the clutch in has no effect (to stop the bike surging forward) despite my having tried to adjust it.

Going to get the left case cover off to have a look at the clutch lever when the shops open and I can get the right bit for the bolts.

The clutch is not part of the electric start mechanism. The electric motor, through several gears, directly engages teeth on the crankshaft. The clutch is part of the kickstart mechanism and must be engaged for the kickstart to work.

 

[acebars]

The clutch is not part of the electric start mechanism. The electric motor, through several gears, directly engages teeth on the crankshaft. The clutch is part of the kickstart mechanism and must be engaged for the kickstart to work.

The kickstart works both in neutral or in gear. The electric start works always but doesn't seem to engage in neutral just spins, in gear it pulls the bike forward.

 

[retiredgentleman]

The kickstart works both in neutral or in gear. The electric start works always but doesn't seem to engage in neutral just spins, in gear it pulls the bike forward.

Here's a link to help you out:
http://www.xs650.com/forum/showthread.php?t=29691

 

[acebars]

Here's a link to help you out:
http://www.xs650.com/forum/showthread.php?t=29691

I am really not sure how this helps. Electric starter always works but only engages the crank when in gear, and holding in the clutch has no effect when in gear or not.

There is no unusual noise other than no cranking when in neutral, the starter sounds like it is spinning when in neutral the crank does not.

 

[retiredgentleman]

I suggest you need to drain the oil, and remove the right engine cover. You also will have to remove the clutch in order to view the starter gears that engage the crankshaft. You will then be able to see why there is no engagement, when in neutral.

 

[peanut]

I am really not sure how this helps. Electric starter always works but only engages the crank when in gear, and holding in the clutch has no effect when in gear or not.

.

I would imagine that if the bike has stood for a year then all the clutch plates will be stuck together and the oil will be like treacle

You're going to need to change the oil and strip clean and rebuild the clutch and oil pump at least

 

[acebars]

I would imagine that if the bike has stood for a year then all the clutch plates will be stuck together and the oil will be like treacle

You're going to need to change the oil and strip clean and rebuild the clutch and oil pump at least

It has stood for years!

PO put new oil in it but I'm afraid car oil so will have to swap that out. Hopefully will get to work on it tomorrow.

 

[peanut]

A mini adventure awaits !

Don't worry there is loads of help on here from some very knowledgable peeps
Take plenty of pictures to upload ..they'll help a lot.

 

[acebars]

Right after much bashing, propane and cursing, managed to get both side covers off without shredding any screws.

Got the the clutch plates off. I have the single long clutch pushrod pre-'73.

3 things I noticed, am I meant to have two ball bearings? Because I only noticed one on the clutch adjuster on the left side. I could only pull the pushrod out from the left side due to solid gunk stopping me, so I hope to god the other ball bearing didn't fall into the crankcase as I was pulling it out.

If it couldn't fall in then unfortunately for me maybe the bike has been messed about by PO.

Found the 2nd ball pushed it through

2nd thing is true to his word PO put in new oil into the bike, unfortunately car oil, so I'd like to clean the clutch plates, would acetone be a good idea?

Just wiped them down with a wrag should be alright when proper oil goes in

3rd thing is clutch adjuster nut is solidly corroded together with adjusting screw and housing, tried to put the whole thing in the vice and slightly bent the whole thing it's no longer circular but more oval, silly me, although it still seems to operate ok. Will try another way to get around this.

Sorted this out, put the clutch back together, mounted the clutch adjuster but without the return spring, bolted left hand engine cover back on, then took a key and gave the nut a good yank, broke free.

I did some damage before, housing is slightly oval, but it still works smoothly so I think it should be ok.

I mean this thing below on the RHS

 

[acebars]

Right think I got it sorted, bike wasn't cranking in neutral because battery was too flat, now it cranks..

Oddly it had the power to pull the bike forward in gear.

Clutch wasn't disengaging due to the car oil that was put in the bike, I cleaned the plates with a wrag also sorted out the frozen clutch adjuster mechanism, now clutch works.

 

[peanut]

well done Ace........you sorted it all by yourself !