ST1300 strange intermittent running

Kev

Joined
Aug 28, 2013
Messages
15
Location
England
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ST1300
Hi ST guru's l hope that l can pick your brains to help solve a puzzling issue that has started on my '05 50k st1300. Please bear with the lengthy blurb. There are a couple of possible issues that may be related. These are not constant but every now and then.
Started possibly with a fast cold tickover, l thought cured via various forum advice re the cold wax unit, possible air in the system. Flushed the system and tickover normal.
Next issue started a month or so later when noticed that it sometimes takes a second or two extra to start the bike. Bike does not feel quite right, very slight difference in the running, cannot say exactly why but feel something not quite right. Changed plugs and air filter, no difference.
Sometimes when turning the bike over from cold l prematurely take my finger off the start button before it fires up. Swear and start again. Only when this happens it will not tick over with me having to keep the revs right up even when it gets up to 3 bars on the temperature gauge, will take anything up to 10-15 miles before it will tick over without cutting out. Runs not too bad when mobile as l have straight main roads, but come roundabouts, changing down without holding 3k revs will instantly cut out and sometimes surges but not very often as l've sussed out the 3k revs.
The odd tickover also happened the other day when cold, l turned on the ignition to check the fuel gauge, turned it off while l sorted a couple of things out , when started the bike only to have it run rough as detailed above.
When warm and running 'normally' sometimes while on the centre stand if l up the tickover revs to 2k and hold it there, have noticed that the revs will sometimes go up and down by anything up to 5oo revs.
When the fuel gauge gets down to 2, sometimes it will run abit rough but not quite as bad as the cold issue. Fill it up, runs fine.
Driving me nuts at the moment. I have looked through the various threads and could be an intermittent fuel pump issue; cold wax unit, another one could be the T bar and pipes or throttle body sync.
I have not changed anything but thought that l would throw my problem out there for help and advice. I try to do most things myself but not overly technical or much good with electrics.
Useful help and guidance appreciated.
 

Mellow

Joe
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I would clean out the 5 way T connector first... It might be the fuel pump..
 
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Kev

Kev

Joined
Aug 28, 2013
Messages
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Location
England
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ST1300
Hi there thanks for the reply, l'll try those issues and fingers crossed. Unfortunately l cannot organise that for another couple of weeks.
 
Joined
Jan 12, 2010
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Eden Prairie, MN
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2003 ST1300
Kev - I'm having similar issues. 03 st1300 with 84k miles on it. I'd had similar issues about 40k miles ago and replaced the fuel pump then which solved it. So - I replaced the fuel pump again and this time very little change although my fuel economy did rise again, just as with the first pump. I'll be digging out the 5-way T as Mellow suggested this time. It's been running very rough, and very much hotter than normal. Plugs are older and on order, so at this mileage I'm thinking just clean up all the vacuum hoses and synch the throttle bodies and see what happens.

Good luck with yours.

bk
 
Joined
Jan 8, 2011
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Arizona
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2007 Honda ST1300A
I'll bring a few things to the table....
First off, you said you did something to the wax unit, if you did, this may be causing you issues in other areas. While some members on the forum have reported "fixing" their bike by altering or adjusting this unit, the service manual clearly states that it is factory set and should not be altered or adjusted in any way.
You may want to consider replacing the thermo wax valve if it has been altered.
I would then remove and clean the 5 way tee with a pipe cleaner and solvent, replace all the lines with new ones, the do a throttle body sync and make sure everything was working smoothly.
I would also replace the plugs (I prefer using a step cooler plug), make sure the air cleaner is clean, run a fresh tank of premium fuel with a couple ounces of MMO and Seafoam in it.
While your tank is up (or removed) I would remove the bolt that holds all the green wires (grounds) to the frame near the left rear corner of the gas tank, and clean off any/all white corrosion that is on it and tighten securely.
You may also want to check your coils (clean corrosion behind the mount where the bolt holds it to the frame).
I would also remove the starter/kill switch assembly, and spray it out with some plastic friendly contact spray, then re-lubricate and assemble.
I have corrected a couple bikes this month with starter/kill switch issues from poor contacts.
let us know what you find.
Igofar
 
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Joined
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CT USA
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07 ST1300
I might add perhaps just buy a new 5way T to have on hand in case you break yours. They are tiny little bits of inexpensive nothing that you can not do without.
 
Joined
Oct 25, 2014
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Waynesville, NC
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Does anyone have a part number for the 5 way T? Where do you get these things and where is it located on the 2007 ST1300?
 
Joined
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JOINT, FIVE-WAY
17201-MCJ-003
Its located underneath the throttle bodies.
 

jfheath

John Heath
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Another possibility is the ignition system. Easy to check out. 3 Possibilities, especially in the UK.


1) Corrosion of copper core in HT lead (green Verdigris)
2) Failure of spark plug cap.
3) Poor earth contact of Coil.

The plug caps screw onto the HT lead - about an inch. It is possible for the copper core to oxidise and rot away leaving a poor connection for the spark. The spark will jump any poor gap, up to a point. When it starts to fail, the spark needs more power (higher revs) to bridge the gap and can be erratic.

The resistance of the Plug caps - measured between the screw thread where the HT lead connects and the end which clips onto the Spark plug - should be 5K Ohms.
4.5K or 5.5K is not good enough. When I fitted brand new ones they read 5.02K There is no equivalent available from places like NGK.

The coils are mounted on the frame and have strip contacts to the frame which can rust. The previous two issues are more likely, but if you're fault finding, anything that suggest poor electrical contact is worth cleaning up.

The HT lead is a simple push fit into the coil, once the plastic gland nut has been removed. A spike deep down in the coil spears its way into the copper strands of the HT lead. The lead has a plastic 'grommit' which is glued firmly near the coil end of the HT lead. The gland nut pushes against this to keep the HT lead in place in the coil. There is nothing special about the HT lead other than this grommit, and the extra thick tubing which slides over it. It is simple copper cored HT lead.
If removing the HT lead, put a mark on the lead where it meets the plug cap. This will give an indication as to how far you have to screw it back on again. IT is more or less an inch. WD40 helps make this job easier.

Left knee, nearest spark plug. The lead is quite tight, and if someone has routed the HT lead incorrectly under the main harness, then it is impossible to remove the plug cap without taking the faring off. If this happened, I wouldn't put it past a time-strapped mechanic to cut the HT lead and replace it with bog standard - leaving nothing to hold the lead onto the spike in the coil. There is nowt wrong with this as a temporary fix, but it won't last a long distance.

Re the fast idle - It is normal for the engine to race away as the engine is warming up. Both of my ST1300s have done it from new and it is most noticeable on the cold frosty 7:00am commutes. 2500-3000 rpm is not uncommon for a short while before it calms down. It hasn't done it for many years, but I'm fortunate enough now not to have to take the bike out for the cold morning commutes any more. The handbook says not to ride the bike until it is warmed up, presumably because the revs can get quite high.


I have also found that if the engine is turned off before it is warmed up, it can be sometimes a tad hesitant to start up again.

I had odd tick over when I was trying to troubleshoot my problems, which turned out to be 2 faulty plugs and 3 faulty leads. I wrote up and illustrated what I found and what I did - PM me with an email address if you want it - I'll send a pdf. I haven't published this on this site yet.

[edit]
Kev requested a copy, but I can't send it by private mail, so I have created a new thread in this forum here, in case it is useful to anyone else.
I'm not sure if the suggestions will help in this case as it assumes the problem is with the ignition - but the link is here should anyone want it.
[/edit]
 
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Joined
Jan 8, 2011
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Where do you buy the vacume hose that go to the T?
Prestone makes a kit #wvo532 - 5/32 x 1.83m (4 mm) - windshield washer hose/vacuum tubing.
A package (6 feet of hose) is about $5.00. I normally get it at the local autozone.
 
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Kev

Kev

Joined
Aug 28, 2013
Messages
15
Location
England
Bike
ST1300
Hi guys, thanks for the replies, with regard to the wax unit, all l did on that one was to fill a hose connected to the water system with coolant and blew it through to try and fix any air locks. I did not adjust any threads. Worked great for a while then everything else gradually started. I'm finally hoping to get to grips with things over the next couple of weeks so starting with electrical connections and simpler things. Mind you my thoughts keep coming back to the fuel pump, a couple of times just lately l have run the fuel down well into 2 bars and it does not run too well, fill it up and it runs fine. It is almost as if the weight of the fuel in the tank helps 'push' the fuel through the system. Anyway will have a look at some of the connections, T piece and hoses and in the mean time will locate where to get a fuel pump just in case. Again thanks to all.
 
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