Fueling problem

[Auron]

Pump is in (strainer sock was a perfect fit Larry) but no change in performance.
Runs great cold, idles perfectly and accelerates strong. Gets worse on really hot days, like 90F+, especially when the engine gets heat soaked from being stuck in stop n go traffic.
Still waiting on the main fuel filter, packing gasket and crush washers ($9 ea!!) which are back ordered.
I also read that the coils can have corrosion issues at their connections or mounting bolts which can be affected by heat and raising resistance and causing ignition problems. I’ll check that later too, but since it only seems to power down and not stall, I’m doubtful.

Also tried the heavier throttle hand approach, but it seems to increase engine heat and consume more fuel.
Perhaps I’m just used to the older bikes with less tech. and lower operating rpm.
The search for Zen continues.

Dammit

 

[Auron]

When you say it runs good when cold? How long is that?

 

[Rob20111]

When you say it runs good when cold? How long is that?

About 40 minutes.
I took it apart yesterday and found rust/corrosion on the right side ignition coil lugs (see pics) and cleaned both coils up.
Hope to get out for a test ride this weekend.
My theory is that perhaps the corrosion is causing increased resistance, which after a while (40 mins?) over heats the coil causing 2 cylinders to run weak spark or even drop out.
Fingers crossed.

 

[SMSW]

...and crush washers ($9 ea!!) which are back ordered....

Full disclosure: I did not read this thread, but saw your post. If you are talking about standard aluminum or copper crush washers, you can get them in a plastic box of assorted sizes from Amazon, or go the expensive route and buy them from McMaster.com. While Amazon provides a number of different sizes for an impressively low price, none of them will fit your application ( ) but McMaster will tell you exactly what you are getting.

If you are getting an OEM special material crush washer, ignore this post.

I bought the Amazon kit and have used maybe a couple of them.

 

[Josh_ST]

About 40 minutes.
I took it apart yesterday and found rust/corrosion on the right side ignition coil lugs (see pics) and cleaned both coils up.
Hope to get out for a test ride this weekend.
My theory is that perhaps the corrosion is causing increased resistance, which after a while (40 mins?) over heats the coil causing 2 cylinders to run weak spark or even drop out.
Fingers crossed.

That corrosion is a good catch! Could very well be causing your issues!

 

[Rob20111]

Just back from a 45 min test ride. Weather much cooler today, so conditions not identical. The coil cleanup seemed to give a power boost, goes like a house on fire, I guess that a consistent full voltage spark will do that, but the hesitation remains.
Most noticeable in 1st, 2nd and third gears at 2500 - 3000 rpm.
Give her some juice and it’s fine.
Snugged up my throttle body intake boot clamps (one was quite loose) and synched again.
Still waiting for the new fuel filter to arrive.

 

[Auron]

Just back from a 45 min test ride. Weather much cooler today, so conditions not identical. The coil cleanup seemed to give a power boost, goes like a house on fire, I guess that a consistent full voltage spark will do that, but the hesitation remains.
Most noticeable in 1st, 2nd and third gears at 2500 - 3000 rpm.
Give her some juice and it’s fine.
Snugged up my throttle body intake boot clamps (one was quite loose) and synched again.
Still waiting for the new fuel filter to arrive.

Now that where we differ… mine is 5th gear only. 3750 rpm and up.

 

[Rob20111]

New filter arrived and installed today. And again, no difference. In fact it felt like it idled rougher.
I’m losing my mind.
The last synch looked like this.
Keep in mind everything is bouncing when I snapped the pic.

 

[Auron]

New filter arrived and installed today. And again, no difference. In fact it felt like it idled rougher.
I’m losing my mind.
The last synch looked like this.
Keep in mind everything is bouncing when I snapped the pic.

Lost my mind a while back. So annoying to not be able to fix a simple problem

 

[Rob20111]

Lost my mind a while back. So annoying to not be able to fix a simple problem

The other problem is that some folks say it’s not a problem, that it’s normal, and you just have to compensate.
No, it’s not normal.
My FJR was injected and didn’t behave like that, neither did my 1985 Honda Goldwing GL1200 LTD, very earliest injected bike.
I’m starting to spend more time wrenching than riding, and that’s not good for a sustained long term relationship with the ST.
The hunt continues.

 

[Auron]

It’s definitely not normal. There is a spot in the revs where it’s less responsive because of the EPA but this feel like you’re running out of fuel.

I’d sell mine if the buyer was ok with the problem but good luck with that…

 

[Auron]

Here’s what I don’t get, if it were mechanical, it would be getting worse over time. But if it were some kind of vaccine leak or hose problem, it pretty unlikely others wouldn’t be having the same problem.

 

[Auron]

The other problem is that some folks say it’s not a problem, that it’s normal, and you just have to compensate.
No, it’s not normal.
My FJR was injected and didn’t behave like that, neither did my 1985 Honda Goldwing GL1200 LTD, very earliest injected bike.
I’m starting to spend more time wrenching than riding, and that’s not good for a sustained long term relationship with the ST.
The hunt continues.

Any luck?

 

[Bmacleod]

I have 2 suggestions. The first would be to find another ST owner to swap rides to see if you in fact have an issue beyond the normal "stumble" these bikes are known for. This MAY stop your quest for a perfect bike and save you some money and headaches. If there is in fact an issue with your bike, and I dont doubt you feel there is, the next step I would take, if it were my bike is to get a fuel pressure gauge set up and run it with the gauge to monitor the pressure when it acts up . I cant help but think this sounds like a fuel problem. Fuel pressure is dependent on 2 main items. The pump creates pressure and the regulator regulates the pressure. The regulator is the more important part to how the bike runs. Fortunately, we dont see many issues with the regulator. However, the regulator has always been discussed as a possible rideability issue, causing exactly the issue you are describing, but to a lesser degree. I cant help but wonder if the issue could be a weak regulator. Like I said, if it were my bike, this would be the next step and if the fuel pressure is solid, one could rule out fuel issues move on to other possibilities...

 

[Rob20111]

Any luck?

Slight improvement but not completely cured. Still trying some things.
Next step is starter valve cleaning as oerKarry, and I’m going to replace the vacuum hoses again with a smaller ID size to rule out leaking, as it only happens when hot.

 

[Auron]

I’ve noticed it’s been a real pain to start during the winter. Gets down in the low 20’s sometime in my garage. Takes several tries and opening the throttle. That mean anything?

 

[jfheath]

Batteries don't like the cold. Mine stays on a smart charger most of the winter. We get down to -4 or 5 deg C quite often - sometimes -11. It survives those OK and starts much like in summer.
20F is about -7C. But my 1100 never used to - I didn't have a battery charger and it was always winter when it died - the engine would turn over OK-ish, but it was reluctant to fire. Battery used to last 3 or 4 winters. Now its about 7 or 8 years with the smart charger. I don't know cos I changed it early suspecting a problem - but it is still charging and holding its charge.

 

[core-aggie]

Batteries don't like the cold. Mine stays on a smart charger most of the winter.

^^^^^^ this !

During heavy cold snaps, I rotate the trickle (smart) charger from one vehicle to the next, daily.

Even when it's not cold (like now, back in the 70's), I put the trickle charger on each vehicle in turn, at least once a month, for battery longevity.

 

[Auron]

Battery is fine. Cranks like it should. It’s the engine that doesn’t want to wake up

 

[Kevcules]

I’ve noticed it’s been a real pain to start during the winter. Gets down in the low 20’s sometime in my garage. Takes several tries and opening the throttle. That mean anything?

Your battery started your engine even when cold using a little throttle after a few tries, so it's probably ok unless you could tell it was turning over slower?
An engine needs more fuel when they're cold to start and your ECM should be doing that for you instead of you having to open the throttle. Sounds like fuel starvation, partially plugged injectors etc and then intermittent starvation while running also.
I've never had power loss or stumble while riding after my engine gets to operating temps. I've only seen a slight stumble when the engine isn't warmed up yet and then slowly applying throttle at take off.
Certainly a strange one. Not normal at all IMO