A bit more help

[Fields11789]

Don't sweat the starter not engaging yet. It needs to grab a shaft to start turning it. Using the wrong oil, cold oil, or weak battery can cause it not to grab. If your oil is right and battery is strong, ride it and it will probably go away after a bit. That's been my experience and others have reported similar experiences.

Thanks for the reply. Hopefully it sorts itself out. Fingers crossed. Its only been filled up this one time since the rebuild. Hopefully it just needed some oil flow? Im using Mineral Oil SAE 30 at the moment. The intention is to dump that oil and put in a 20w-40 or similar.

Right now Im happy she fired up without any hesitation. Even after being re-built.

[skids]

Don't sweat the starter not engaging yet. It needs to grab a shaft to start turning it. Using the wrong oil, cold oil, or weak battery can cause it not to grab. If your oil is right and battery is strong, ride it and it will probably go away after a bit. That's been my experience and others have reported similar experiences.

I have had three running xs11's that had occasional issues with the starter clutch when the oil is heavy viscosity, or when using 100% synthetic oil (don't do that), and especially when it is very cold. Once you get the oil warmed it will do better. It seems to grab better when the oil is not new.

[Fields11789]

A bit more help

Thanks everyone for the helpful posts on my last thread.

Can you help me with these issues

1
The motor starts easy, and idles ok.
When I gently ease the throttle the revs hang for a bit then slowly drop. If I rev to high or too quick it quickly revs up to about 3500 and just stays there.
Has three of the old genuine mikuni jets in (cleaned). 1 carb has those KL jets (I know they are rubbish) as I made a mess of one set while removing. (I have a new genuine set of mikuni jets in the way).
the throttle cable does not hang up anywhere and snaps back into place just fine.
Is this a vacuum issue? I'm running the 30year old boots and plugs at them moment. It's the only weak point I can see.
Plugs are a bit blackened already

2
I dumped the engine oil after running it for a bit today. It just sounds a bit noisy. And I was unhappy as I originally had flooding carb issues which I'm 90% sure went forward into the head.
I ran some liqi-moli engine flush through it ran it and when dumped the oil came out milky and a bit thin.
Is that a symptom of fuel in the oil or just a by product of using these engine flushes?
I had SAE30 in it if that makes any difference

[Radioguylogs]

Issue#1: "Idle sticks high" can be a symptom of rich pilot jets, particularly the K&L wrong-sized pilot jets.....and you see totally black plugs when this happens.....but you only have one K&L jet.

As you mentioned "Idle sticks high" can also be a vacuum leak. Don't forget to consider the Butterfly Shaft Seals. You can find vacuum leaks by sniffing with with unlit propane torch or by lighter fluid.

BTW, carb boots may look cracked on the outside, but if you look inside, they are usually perfectly fine.

Issue#2 It's hard to know what caused the oil to look milky.

I doubt gas-oil is the cause as I have had gas-oil in two of my bikes when I bought them, and the oil was thin, but not milky.

I am not familiar with liqi-moli, so I have no idea if it would make the oil thin and milky.

I do know that water makes the oil appear milky, but the water separates, so it is easy to diagnose.

[TopCatGr58]

Hey there Fields,

First off, I merged your threads because you're still talking about the same bike and running issues, AND we like to see the history of the bike, what was done to it, what was suggested, tried, worked or not, etc.. When you start posting in a bunch of other threads, info gets lost, forgotten, and you end up having to repeat yourself a lot with repeated requests for info about what you've done, tried, etc.!

Next, aside from vacuum leaks at the intake boots or synch caps, or carbs shaft seals, another contributing factor is that these 4 carbs have to be vacuum synchronized to make them work together....sorta like a 4 horse team....if one's pulling harder, then the others will follow suit. A hanging idle is classic for poorly synched carbs. As stated, the intake boots are double walled and can look bad outside, but be fine inside....but folks have reported old crumbling rubber on the part that mates with the engine head, so you might want to take them off, inspect, clean, and even install with sealant like Threebond or similar....RTV isn't as good against fuel! The synch port caps can also harden from heat, and can leak even though they seem connected to the metal port.

Okay, others have answered about the milky oil. I'm not familiar with Mineral Oil SAE30, or are you just saying that it's regular DINO oil vs. Synthetic? The piston/ring to cyl wall clearances/tolerances are much higher/wider than modern engines, and that combined with the air cooling, and the temps you get down under, we would suggest using a 20-50 blend/brand of your choice of Dino oil...Walmart(do they have them in your country?) or similar generic brand of 20-50 would be just fine, and just change it every 2-3k miles because it gets contaminated with combustion blow by, so trying to use SYNTH is a waste of $$ to get any kind of extended mile/oil change intervals! These engine are notoriously noisy due to the overhead cams, chain, and only 30 wt oil doesn't help. Also, have you seen the tech tips about the Automatic Cam Chain tensioner? Highly suggest doing that or similar mod: http://www.xs11.com/forum/showthread...nute+cam+chain , don't rely on the OEM CCT, it's a faulty design and Yamaha realized that and changed it to the ACCT shortly after the XS11 series.

Next, 30 year old spark plugs....already carboned up....and you've only been able to run the bike mostly at idle, so no wonder they're blackening. Also, have you checked the plug wires where they fit into the plug caps....can corrode, cause lots of resistance, can unscrew, clean/trim 1/4" off to get down to clean copper, reinstall. Check the resistance of the cap while off...usually 5K ohms....if much higher, can take cap apart...unscrews from plug end, internal resistor, corrodes, clean, test with ohmeter, if still too high K value, replace cap....or put in small spring to replace resistor. Most folks usually can get/find resistor plugs....don't really need resistor caps also....only for radio frequency noise suppression. The OEM coils only put out about 15KV, excessive resistance lowers amount of power getting to plugs to make strong spark.

The Starter Motor just spins a gear/starting clutch assembly that surrounds the crank. There are 3 pinch rollers inside that assembly that slide down an angled slot to pinch/grab the crank like a pipe wrench. So you won't grind any gear teeth when it sounds bad...it's just the clutch slipping and spinning around the crank instead of grabbing it. As stated, a weak battery, as well as very cold/viscous oil can contribute to the slippage. You stated you used an engine flush, so that should help to remove a lot of old varnish and oil sludge and may help the starter clutch get a better grip.

T.C.

[Fields11789]

Issue#1: "Idle sticks high" can be a symptom of rich pilot jets, particularly the K&L wrong-sized pilot jets.....and you see totally black plugs when this happens.....but you only have one K&L jet.

As you mentioned "Idle sticks high" can also be a vacuum leak. Don't forget to consider the Butterfly Shaft Seals. You can find vacuum leaks by sniffing with with unlit propane torch or by lighter fluid.

BTW, carb boots may look cracked on the outside, but if you look inside, they are usually perfectly fine.

Issue#2 It's hard to know what caused the oil to look milky.

I doubt gas-oil is the cause as I have had gas-oil in two of my bikes when I bought them, and the oil was thin, but not milky.

I am not familiar with liqi-moli, so I have no idea if it would make the oil thin and milky.

I do know that water makes the oil appear milky, but the water separates, so it is easy to diagnose.

I originally had a full set of those k&L jets in however swapped them out leaving just one in as one of the original pilot jets were badly damaged when installed by a PO and took some getting out. Didn't want to re-use it in-case I couldn't get it back out. (problem persisted with all K&L or just one)

I checked for vacuum leaks with some starter fluid and noticed a jump in rpm when spraying around the front of intake boot 1-2. I tried to replicate it however couldn't do it again.

The boots seemed OK on the inside when I had it all apart. My thought was maybe it is the seal around the vacuum plugs or the seal to the head itself. I'm going to use some high temp gasket silicone to see if that helps. If it does Im replacing them.

Liqi-Moli is just a more high end engine flush you get from an auto parts store over here. I'm going to assume its what made the oil milky (no mention on the bottle of this) as there is no way the oil was exposed to any other form of moisture except fuel.

[Fields11789]

Hey there Fields,

First off, I merged your threads because you're still talking about the same bike and running issues, AND we like to see the history of the bike, what was done to it, what was suggested, tried, worked or not, etc.. When you start posting in a bunch of other threads, info gets lost, forgotten, and you end up having to repeat yourself a lot with repeated requests for info about what you've done, tried, etc.!

Next, aside from vacuum leaks at the intake boots or synch caps, or carbs shaft seals, another contributing factor is that these 4 carbs have to be vacuum synchronized to make them work together....sorta like a 4 horse team....if one's pulling harder, then the others will follow suit. A hanging idle is classic for poorly synched carbs. As stated, the intake boots are double walled and can look bad outside, but be fine inside....but folks have reported old crumbling rubber on the part that mates with the engine head, so you might want to take them off, inspect, clean, and even install with sealant like Threebond or similar....RTV isn't as good against fuel! The synch port caps can also harden from heat, and can leak even though they seem connected to the metal port.

Okay, others have answered about the milky oil. I'm not familiar with Mineral Oil SAE30, or are you just saying that it's regular DINO oil vs. Synthetic? The piston/ring to cyl wall clearances/tolerances are much higher/wider than modern engines, and that combined with the air cooling, and the temps you get down under, we would suggest using a 20-50 blend/brand of your choice of Dino oil...Walmart(do they have them in your country?) or similar generic brand of 20-50 would be just fine, and just change it every 2-3k miles because it gets contaminated with combustion blow by, so trying to use SYNTH is a waste of $$ to get any kind of extended mile/oil change intervals! These engine are notoriously noisy due to the overhead cams, chain, and only 30 wt oil doesn't help. Also, have you seen the tech tips about the Automatic Cam Chain tensioner? Highly suggest doing that or similar mod: http://www.xs11.com/forum/showthread...nute+cam+chain , don't rely on the OEM CCT, it's a faulty design and Yamaha realized that and changed it to the ACCT shortly after the XS11 series.

Next, 30 year old spark plugs....already carboned up....and you've only been able to run the bike mostly at idle, so no wonder they're blackening. Also, have you checked the plug wires where they fit into the plug caps....can corrode, cause lots of resistance, can unscrew, clean/trim 1/4" off to get down to clean copper, reinstall. Check the resistance of the cap while off...usually 5K ohms....if much higher, can take cap apart...unscrews from plug end, internal resistor, corrodes, clean, test with ohmeter, if still too high K value, replace cap....or put in small spring to replace resistor. Most folks usually can get/find resistor plugs....don't really need resistor caps also....only for radio frequency noise suppression. The OEM coils only put out about 15KV, excessive resistance lowers amount of power getting to plugs to make strong spark.

The Starter Motor just spins a gear/starting clutch assembly that surrounds the crank. There are 3 pinch rollers inside that assembly that slide down an angled slot to pinch/grab the crank like a pipe wrench. So you won't grind any gear teeth when it sounds bad...it's just the clutch slipping and spinning around the crank instead of grabbing it. As stated, a weak battery, as well as very cold/viscous oil can contribute to the slippage. You stated you used an engine flush, so that should help to remove a lot of old varnish and oil sludge and may help the starter clutch get a better grip.

T.C.

Thanks TC, I wasn't sure how it worked so thanks for that. Makes more sense this way.

So i bench synced the carbs when i installed the jets. they were pretty damn close but obviously will need the vacuum sync. I might have to fork out the dough for a sync set-up.

To my understanding SAE-30 is a single grade oil with a viscosity of 30? I was assured by a guy at the auto store it would be fine for running in and what not. It is Penrite oil so not bad at all. Just not what is recommended. I only got it as i planned on flushing the engine and re-filling with correct grade oil which is a touch more expensive. I have some Penrite 15w-40 here at home which might be just fine.

I think I wasn't clear when i mentioned the "30 year old plugs" when i said this i meant the Sync port covers on the carb boots. The spark plugs that went black almost straight away were brand new NGK 6BES plugs. Only ever run in this motor.

I checked the plug caps and wires. There was some very minor corrosion inside the caps and come greening of the copper on the end of the leads. I cleaned the caps with some electrical spray cleaner and chopped about 1/4 of the wires and re-installed. (I have new NGK caps coming). Haven't tested ohm as yet.

I've noticed the starter clutch is much better since the engine has been running up to temp. Also seems like its back to normal after the flush so hopefully that's the end of that.

[Fields11789]

Also i will consider the CCT mod but have seen them on ebay already made ready to go for about 70AUD. Has anyone had experience with these ebay CCTs

http://www.ebay.com.au/itm/NEW-1978-...oAAOxyF19SFjn1

[3Phase]

Fields, I have a ACCT for my '80G engine and it works fine. There is no rubber pad on the end of the adjuster I have where it touches the cam chain guide so it makes a slight metallic singing but it's nothing horrible, it's a song that's all about me not having to adjust the cam chain tension again, ever.

So not to talk you into or out of spending your own money or anything but you can hardly swing a dead cat without hitting an inexpensive automatic adjuster that'll fit the engine. I pulled mine off of a bike at a wrecking yard not eBay but if you're worried then you can make a good manual tensioner out of the one that's already one your bike, you don't have to buy one. If you make your own you have scads of bolts that you can choose in plain steel, galvanized, parkerized, chromed, nickel plated or stainless; metric or english; fine thread or coarse:-


30 minute cam chain tensioner mod


Enjoy!

[Prothec]

On my 81SH I had some issues with a sticking idle around 3500, just needing a little extra throttle to cause it to climb. For me it seemed to be due to carb balance issues. If I manually retarded the vacuum advance mechanism, idle was fine. I ended up pulling the carbs and did a better bench sync before resyncing the carbs. Getting carb #2 too far off can advance the timing and can make you think you have other issues.

I'm open to disagreements that this was actually the cause of my problems. Maybe I still have other problems that have just been masked. Pulling the advance apart and cleaning and lubricating the advance mechanism had no effect for me and it was already moving freely.

[motoman]

May oughta' get the correct Kenuine Mikuni jets as needed and start the tuning process(idle mixtures/vacuum sync) all over again.