Stalling and idling issue.

Hey all, John from Portland, Oregon here. Two months ago I purchased a 2002 Silverwing with 18k on it. I was having a blast for the first few weeks and then I started having a stalling problem when I'd come to stops. I read a lot of other posts, and started the quest for answers. Now I'm not a mechanic, but I can find my way around this machine pretty well for just two months of tinkering.

I started by adjusting the idle, and trying to balance the mixture using a homemade manometer. Eventually, I couldn't get it to start. I was deflated. Thanks, again, to many posts written by the wonderful folks in this forum I started down the list of possible problems. I pulled the plugs and they were covered with carbon deposits. I replaced those and hurray, it started and was running smoothly. I went for a ride and on the way back I was slowing for a light. Dead. I fired it right back up and just had to give it a bit of extra throttle everytime I was stopping.

When I got home, I started by adjusting the idle, but it's in all the way and hanging around 1000rpm. The idle is running up and down. What's next?

Can I now just assume that I need a new FPR or could it be something else? I appreciate everyone's expertise and I hope I can start contributing soon. You guys rock!

John

PS. I didn't mean to hijack thread, of that's what I did.

Hey all, John from Portland, Oregon here. Two months ago I purchased a 2002 Silverwing with 18k on it. I was having a blast for the first few weeks and then I started having a stalling problem when I'd come to stops. I read a lot of other posts, and started the quest for answers. Now I'm not a mechanic, but I can find my way around this machine pretty well for just two months of tinkering.

I started by adjusting the idle, and trying to balance the mixture using a homemade manometer. Eventually, I couldn't get it to start. I was deflated. Thanks, again, to many posts written by the wonderful folks in this forum I started down the list of possible problems. I pulled the plugs and they were covered with carbon deposits. I replaced those and hurray, it started and was running smoothly. I went for a ride and on the way back I was slowing for a light. Dead. I fired it right back up and just had to give it a bit of extra throttle everytime I was stopping.

When I got home, I started by adjusting the idle, but it's in all the way and hanging around 1000rpm. The idle is running up and down. What's next?

Can I now just assume that I need a new FPR or could it be something else? I appreciate everyone's expertise and I hope I can start contributing soon. You guys rock!

John

The FPR is linked to the intake vacuum by a hose, and that is used to manipulate the fuel pressure so that it drops when the vacuum is high, maintaining a constant relative injection pressure. If the vacuum signal is lost then the fuel pressure may well be too high so excess fuel is injected, giving rich running and fouled plugs. I'd suggest checking or just replacing the rubber vacuum hoses to the FPR as a cheap/easy check.

The FPR itself can also fail, specifically the internal rubber diaphragm can tear, which allows fuel to pass though those vacuum hoses straight to the intakes. Check to see if the vacuum hoses contain any fuel immediately after running, they should be dry at all times.

Given your comment about idle going up and down, that would be a symptom of an air leak into the intakes which takes us back to the vacuum hoses as a possible cause.

While the engine is idling check for a vacuum leak by spritzing the vacuum lines with carb cleaner (use the straw). If the idle speed changes you’ve found a vacuum leak. Could be that those vacuum lines have deteriorated with age. 

If that doesn’t work, and given the age of the scoot along with the fact that you’ve adjusted the idle and balanced the throttle body, I’d say the FPR is the culprit.

Balancing the throttle bodies is the hard part. The rest is easy peasy.

Please keep us posted.

Thanks, Terry. I really appreciate the suggestion. I'll start by replacing the vacuum hoses and go from there. While I like that I've learned so much, I am starting to wonder whether I should just but the bullet and pay someone to fix it!

John F. wrote:

Thanks, Terry. I really appreciate the suggestion. I'll start by replacing the vacuum hoses and go from there. While I like that I've learned so much, I am starting to wonder whether I should just but the bullet and pay someone to fix it!

I checked the service manual and the likely causes for stalling/rough idle/hard starting are listed as air leaks, idle speed or starter valve synchronisation misadjustment, pinched fuel hose or contaminated fuel.

No mention there of the FPR. The FPR is listed as possible cause of poor fuel economy or poor drivability.

That's really helpful, Terry. Thank you so much. I've ordered a service manual but haven't received it yet and it seems that was a good choice.

It may or may not be related but these problems didn't initially start until I topped off my tank with shell supreme. I will check those other possibilities, do a seafoam treatment and cross my fingers. I'll try and update my progress to help others in the future. I really appreciate your time and consideration of my scooter issue. Cheers!

John

After a bit of snipping ....

John F. wrote:

then I started having a stalling problem when I'd come to stops. I read a lot of other posts, and started the quest for answers.

I started by adjusting the idle, and trying to balance the mixture using a homemade manometer. Eventually, I couldn't get it to start. I was deflated. Thanks, again, to many posts written by the wonderful folks in this forum I started down the list of possible problems. I pulled the plugs and they were covered with carbon deposits. I replaced those and hurray

When I got home, I started by adjusting the idle, but it's in all the way and hanging around 1000rpm. The idle is running up and down. What's next?

Can I now just assume that I need a new FPR or could it be something else?

From the information above I'd hazard a guess that your initial problem was caused by a 'lazy' spark plug & has been worsened by you 'trying' to balance the air screws there is a very specific procedure for doing this (when your FSM arrives read 5-61 for details) if your maximum idle is only 1000rpm my guess is it's running too 'rich' & the erratic idle is because of overfuelling

As a member of the Ministry for Stating the Bleedin' Obvious.....have you checked the air filter?

My 2001 SW gets a bit temperamental when she wants a new air filter or/and plugs. Plugs always look a bit sooty too.

Loose marbles,

It was one of the first things I replaced when i got the bike. But, it might not have been OEM! That better not be it!

The plot thickens. . .I just added several ounces of seafoam and let it sit. I started it and, voila, it's running smoothly! But like all good things, after it warmed up a bit it started idling from 1300-1500! Slowly but surely, I'm working through the list of possibilities. This is like a bad mystery film. I sprayed the vacuum lines with soapy water but didn't notice any leaks. Time for some more reading up on synchronization.

John,

Don't use soapy water on the vacuum lines " to find a leak".

They're sucking in...….and you don't want soapy water going into the induction system.

The soapy water treatment is for pressure lines that might be blowing out, and you will see the bubbles from the soapy water.

Like Cosmic_Jumper (Tim) suggested, spray with carb cleaner.

Wow! Yep, I've been breathing way too much exhaust! Carb cleaner it will be.

Have a bit of care with the carb cleaner; it is much more agressive on plastics that say WD40 or similar. I used a fair bit of CRC Carb Cleaner (love the smell, might be addictive) on my ST1100 carbs and managed to melt quite a few things like a pen and part of my digital micrometer. Might do the same to bodywork, electrical plugs or the air plenum?

Terry Smith wrote:

Have a bit of care with the carb cleaner; it is much more agressive on plastics that say WD40 or similar. I used a fair bit of CRC Carb Cleaner (love the smell, might be addictive) on my ST1100 carbs and managed to melt quite a few things like a pen and part of my digital micrometer. Might do the same to bodywork, electrical plugs or the air plenum?

Good to know. I'll definitely go easy.

Well, I went out to work on it again and now it won't start, even with the idle screw completely in. This is so nerve wracking! What can cause such a huge variation of outcomes besides user error (I hadn't changed anything from earlier).

I've read several posts about the throttle body/air screws but I haven't seen a definitive "starting position." I'm thinking of starting at 3 if I can't get it started. Other suggestions?    

Thank you to everyone who has taken the time to assist me. You guys are the best.

John

Wont start because...? Nothing happens when you hit the Start button? Or, cranks but wont fire?

If you haven’t previously spritzed the left side start/brake switch contacts and the right side Start switch contacts then you should use some WD-40 or CRC Contact Cleaner on those. 

Do be mindful of Terry‘s cautions about melting tupperware.

Shorting the B/W & G/R wires on the left side switch will bypass that switch function and identify whether the switch is bad. But DON’T TRY THIS because IT’S DANGEROUS to start the bike with this safety feature bypassed.

Unless you’ve got a new battery you should take it out and have it load tested at your favorite Auto Zone or some similar place. If the battery is “weak” it will still crank when you hit the Starter but there won’t be enough juice to power the ECM and rest of the start circuit.

Cosmic_Jumper wrote:

Wont start because...? Nothing happens when you hit the Start button? Or, cranks but wont fire?

If you haven’t previously spritzed the left side start/brake switch contacts and the right side Start switch contacts then you should use some WD-40 or CRC Contact Cleaner on those. 

Do be mindful of Terry‘s cautions about melting tupperware.

Unless you’ve got a new battery you should take it out and have it load tested at your favorite Auto Zone or some similar place. If the battery is “weak” it will still crank when you hit the Starter but there won’t be enough juice to power the ECM and rest of the start circuit.

It won't fire. When I give it a little gas, it wants to start but doesn't make it over the hump. It was doing this the other day, and eventually I got it started but it's weird. I think the bike just doesn't like me.

The battery is a month old but at this rate it's going to be dead soon!

Could be you’ve flooded the engine. Hold the throttle wide open while you are cranking it. Supposedly that prompts the ECM to go into some kind of starting mode while also clearing the cylinders.

Maybe check the plugs again to see if they are fouled again.

Cosmic_Jumper wrote:

Could be you’ve flooded the engine. Hold the throttle wide open while you are cranking it. Supposedly that prompts the ECM to go into some kind of starting mode while also clearing the cylinders.

Quite right; the owners manual advises to do this if the engine is flooded. It says that when the throttle is 100% open during cranking, the ECM cuts the fuel supply. The manual advises holding the throttle wide open and then pressing the starter button for 5 seconds. Then release the throttle and try for a normal start. If the idle is unsteaday it advises giving a little throttle. If the engine does not start, wait 10 seconds and try again.

One other possibility to look at would be a blockage of the starter valve/idle circuit. From pics online this appears to take in air from a small port between the two main intakes and then split the air through the SVs and into the intakes downstream of the butterflies. If the intake was blocked the engine would starve for air at low/no throttle opening, and presumably run rich as a result, and the idle adjuster would not work very well. You'd need to pull the throttle body out to check this one through.

Ok, so I pulled the plugs and they were already pretty black and did have had on them. Cleaned them up, put em back in the adjusted the throttle body screws so the were both 1.5 turns. Cranked it and it just wouldn't started. Sounds like it wants to but nothing. I'm afraid my battery will end up being too early to fire if I keep this up. I guess it's time to start dismantling the beast. Thanks, fellas. I'll keep at it and fill you in.

John,

You have a Private Message with a link.

There is nothing to be gained by continually cranking, and hoping that by some miracle, things have changed.

This only serves to take years off the starter and ancillary components.

Even if it does start (badly) there is a problem somewhere that isn't going to go away by itself.

First charge your battery, and then go though the Troubleshooting Section at the rear of the manual.

Patience...….patience...….and more patience...….you'll get there, and have the satisfaction that you found the problem.

Donie wrote:

John,

You have a Private Message with a link.

I guess that the link leads to ... wotmeworry ... ? If so then not all the information is correct for OP's machine, as that version is for the later year models with exhaust gas sensor, etc

Fingers crossed it might help him while he's waiting on his manual purchase in the mail.

In his post he said he had bought a 2002, and since the 'wotmeworry' covers 2002-2013 he might be in luck.

Unless his machine is a 2001 registered early 2002.

John F. wrote:

I've read several posts about the throttle body/air screws but I haven't seen a definitive "starting position."

Sorry but Honda do not publish that information bud.

If it's badly flooded your best option is, remove both spark plugs, crank it over for 10 seconds & then walk away from it for several hours to allow fuel between piston & bore to evaporate

Donie wrote:

Fingers crossed it might help him while he's waiting on his manual purchase in the mail.

In his post he said he had bought a 2002, and since the 'wotmeworry' covers 2002-2013 he might be in luck.

Unless his machine is a 2001 registered early 2002.

Indeed bud, it's better than no at all, particularly for US members as it's for the FSC not the FJS, but that's mainly because of wiring differences & no H.S.S on the other side of the pond

Thanks, all. I'll work on getting the gas evaporated, continue to check out the manual, and exercise as much patience as I can muster. Much appreciated, everyone.

The saga continues. . . So I was able to determine that the Fuel Pressure Regulator was bad and I replaced it. I changed the oil, which definitely was fouled by fuel, and tried to start it. The engine would turn over but it still won't start. I checked the plugs again to make sure I had spark. R hand side was fine, but very little spark if any on the Left. The continuity in the plug wire was in the 12,000 ohm range which seems about right. Is my problem the Coil? Thanks for reading!

John

There's nothing in the Swing manual to describe the required resistance. The ST1100 manual that I have has specs for the primary side of the coil (2.18-3.19ohm) and the secondary from plug cap to plug cap (22.5-27.5 kohm) or plug wire to plug wire (caps removed, 13.5-16.5 kohm). Maybe change the plugs first?

Thanks, Terry. I think I read somewhere else regarding the proper ohms.

The plugs are new. And when testing the spark I used the plug that did have a good spark on the other wire just in case and there still was nothing. I'm at a loss.

Good thinking with the plug swapping. As far as I know, the coil is continuous and fires both plugs simultaneously. Is it reasonable to switch the wires over on the coil and see if the problem stays with one side or transfers? That would then point to a fault with either the wire (changes side) or the coil (stays the same side).

The plugs caps probably have removable resistors, you may be able to insert a screwdriver and remove the retaining screw and pop the resistor out for a look (for corrosion).

Unfortunately, the wires are not interchangable. I couldn't see any screws in the caps. I'm wondering if there isn't a good connection between the plug and the cap. The plug just pushes on so it may be loose from taking them on and off. I'll try and test my idea tomorrow.

Here's some info on the plugs caps and resistors.

https://www.randakksblog.com/spark-plug-tricks/

Late to this party ,,, as they say. But with somewhat similar experiences I had a couple of years ago and felt it was idle screw and gas flow pressure, what solved my problem was a new battery. Think I replaced the spark plugs at that time too. A weak battery can cause all sorts of problems, was what I found. It was with the help of the people here that kept me from making things worse. The adjustments were working fine before the problems of idle to stall, which you describe John. The battery was probably OEM on my 2005 bike which made it about 3 years past the likely life of the battery.

Hope this helps somehow.
Mike

Mike, I second the need for a strong battery, I had a similar issue, the injectors do take a lot of power including the pressurized fuel system.

Thanks for the Feedback, all. Terry, I did finally notice the screws in the caps after a good nights rest.  

This morning I decided to do something different. I pulled both of the plugs and reinstalled the old ones.  Guess what?!  It started!  Of course in all my excitement I got the vacuums balanced and put all the "tuperware" on and went for a test drive.  OH NO! When I tried to accelerate it was a little rough and I couldn't get going faster than 40mph with the throttle open.  So, I'm assuming I need to adjust the air screws again?  It has a new air filter so I don't think that's the problem. I've got my fingers crossed that it's something simple and reading the service manual now.  

John

Battery is a cheap and simple to change thing that could made a big difference.

I believe that the air adjustment screws only adjust the vacuum at idle. They balance the vacuum for each cylinder, which in turn balances the fuel required at idle for each cylinder. Does nothing above idle. That is my 2¢.

Thanks everyone, for your help on the first of I'm sure many issues with my Silverwing. By changing the plugs and replacing the FPR the engine is running fine and I have a new issue, of course. If you want to assist, it can be found here:

https://www.silverwing600.com/t11741-clutch-driven-pulley-issue#119874

You all are awesome, and if you ever make it to Portland after this whole pandemic thing works itself out let me know and hopefully we can go for a ride.

Cheers,
John

I'm having this same issue