Overheating issue

[Langers]

I seem to have a significant overheating issue. The other day, getting back onto the freeway after a mild ride through the hills, the engine started surging and wouldn't hold speed. I pulled over and turned the motor off (actually, I think it stalled). I turned the key off and then back on again and noticed the air temp gauge read 50+ degrees. I waited a couple of minutes and tried to head off but the surging returned immediately. The outside temperature was around 33 and I was riding up an incline.
I pulled over into the shade and called the RAA. About an hour or so later the RAA turned up, we chatted about the possibilities and we settled on overheating causing fuel surging. The chap suggested I ride through to Crafers and he'd follow and if no issues we'd leave it at that and I'd head home (a downhill run all the way). There were no issues and I got home ok.
Today I've stripped off all the fairings and found a pretty obvious leak from the water pump inspection hole. I opened the radiator cap and it was full. The overflow tank was empty.
I ran the bike (it idled as per normal) until 3 bars showed on the gauge - I noticed the fans did not come on. I turned it off for a few minutes for things to heat up and then fired the bike up again, ran it for another 5 minutes - again no fans operating.
Any thoughts on this will be appreciated - I'm suspecting the relay may need replacing (the 30amp fuse is fine). I'm also suspecting a new water pump may be in order.
Thanks ... Mark

[Brock]

The thermal sensor could have failed, or the bike actually wasnt getting hot...  Did you try opening the fuel cap, there may be a pressure /vacuum relief failure, and the bike wasnt getting fuel through the pump

[Langers]

Sorry, I should have mentioned, the first thing I did when I first stopped was open the fuel cap because the surging felt like fuel starvation. Opening the cap made no difference when I took off a few minutes later, the surging started almost immediately. I was looking at the oil level window this afternoon and didn't much like the look of the oil colour. The last oil change was about 6,000 km ago and the oil seemed a bit darker/khaki colour - I do hope I don't have a blown head gasket. When I started the bike up this afternoon with the radiator cap off there was no bubbling but the engine was cold and perhaps the thermostat prevented that disheartening symptom. I'm going to drop the oil tomorrow and have a closer look.

[StinkyPete]

Good Luck with that.      I sure hope your oil is not water contaminated.   

[Jdbiker]

Hi Langers, sorry to hear of your ST issues. The air temperature gauge on the 1300 only shows the ambient temperature and has no relation to the coolant temperature, the high temperature indicated is quite normal on a hot day, it’s just the radiant heat from the road surface and engine. Did the coolant temperature gauge go past 4 bars or into the H ? Although overheating could have caused the surging and stalling, there are any number other reasons, fuel starvation being the most common. It’s is very unlikely to be a blown head gasket seeing that the radiator was full. Top up the reserve tank and take it for a run, if coolant temperature remains at 3 bars while on the move then overheating is an unlikely cause. A slight leak from the weep hole on the water pump is normal on older models. Hope you have it sorted with no major issue ( not head gasket 😳)
 
Cheers.
JD.

[Langers]

Thanks all. I think I may have tracked down the culprit (fingers crossed).

I flushed the cooling system and changed the radiator fluid. Despite evidence of leakage from the water pump housing in the past, nothing is showing at the moment. I took Scarlett for a run (undressed - um Scarlett that is) and there were no issues but it wasn't a long run and it wasn't particularly warm at the time.

With too many things on the go at the moment I haven't had a chance to do much of anything for a month (and having a 2nd bike removes the urgency for repair). Anyway I've done a bit more digging and I'm pretty convinced this may be the issue (from: https://whereisbobl.com/st1300/st1300-fuelpump.html ):

"As reliable as the Honda ST1300 is, there are a few known weaknesses. One of them is the Fuel Pump. Frequently the pump will fail somewhere around 100,000 miles, especially if you ride like Ironbutt riders tend to do, bringing the fuel level down very low, frequently. Pump does not like to be hot. Fortunately, it follows a graceful degradation failure. It will start to buck and lose power, possibly stalling. It will do this until you either let it cool down or fill it up with fuel. It may not do this again for tens of thousands of miles. Eventually it will repeat, and will no longer work correctly, even with a full tank. It is a good idea to replace it as soon as it screws up the first time.

I suspect that one thing that instigates the issue is letting a fairly empty tank get very hot, then taking off, which cools the vapor, creating a vacuum. I think this strains an already old fuel pump. I have no data to back this up, but it fits with my occurrence and descriptions that I have read from other riders."

The surging I experienced and then no problems once the bike has cooled down suggests it is similar to the article AND coincidentally, Scarlett has just kicked over 158,000 kilometres - pretty close to 100,000 miles.

I'm about to order a replacement pump and filter kit from the States and have a go at installation myself (unless I come to my senses and take the replacement parts to a service centre where someone who knows what they are doing and do the job - but where's the fun in that?). I'll keep you posted.

[Shiney]

Looking forward to the next update
 

[StinkyPete]

That's a good bit of research, andf I surely hope it fixes your problem.   Do you have a workshop manual?

[Langers]

Yes Pete, I downloaded the 2003 Honda Service Manual not long after I bought the bike.

[Langers]

Just to add to the story, I ordered the filter kit from Quantum Fuel Systems of Ventura, California (paying by PayPal) before I read the piece on older fuel pumps succumbing to heat. Later that day, after realising it was probably the fuel pump causing the problem but also realising the filter should also be replaced at the same time I thought - bother, two lots of shipping costs (around $25-$29US). So I sent an email asking if I could order the pump as well and get it put in with the filter order.
I woke up today to find an email advising they had cancelled the order and refunded the money and would wait for me to put in a new order for pump and filters (which I have done). This saved me at least $35 in extra postage. The address of these people is: https://www.highflowfuel.com/ if you ever need them (although lets wait to see how my little exercise goes first). So far they look to be a very professional business.

[Dragonstaff]

Mine having ticked over 154,000 last week, I might have to watch for the same issue in the not-too-distant future. I do try top up at 3/8ths of a tank or thereabouts, but who knows what previous owners did?

I also look forward to further updates.

Edit: After a look at the site, the pricing doesn't seem too larcenous either, even allowing for $US.

[Langers]

Quick update. I ordered the pump, filter and necessary bits from Quantum Fuel Systems, California on the 22nd and the gear arrived at my front door on the 28th.  Wow - and I thought there were supposed to be supply chain issues.

Now I need to go for a ride to use up as much fuel as I can before opening the bottom fuel tank. The crosses one has to bear.   

[StinkyPete]

.....I ordered the pump, filter and necessary bits from Quantum Fuel Systems, California on the 22nd and the gear arrived at my front door on the 28th.  Wow - and I thought there were supposed to be supply chain issues.

Excellent service indeed, and now we wait for the results once the new pump etc is fitted.   

[Langers]

The new pump was fitted today. Advice from those who had done it before and written it up suggested it was a 1 hour job. Hmmm for those who are confident diving into the unknown I suppose it could be that quick. In my case, 3 hours would be closer, but it was a pretty leisurely 3 hours.
It all went together pretty well - only a couple of parts left over. This was done on purpose. At the bottom of the fuel pump where the "tea bag" filter sits, it sits in a large plastic "bag" filled with stainless steel wool (for want of a better term). This stuff looks just like the stainless steel used for cleaning pots and pans. Also in the plastic bag is the end of a pipe, I'm assuming for fuel return. Well, a good 1/2 to 3/4 of an hour was spent trying to get this to marry up with the new tea bag strainer - but in the end, no luck so I put it all together without the bigger plastic bag and stainless steel. I'm not sure what the effect will be by not having the fuel return dampened. I'll find out I suppose.
The photos attached show the original set up and the second photo shows the bits that make up the pump and filters.
Once all back together I started the bike and it all started and ran ok. I then added 15 litres of fuel and there appear to be no leaks (fingers crossed). I'm heading to Strathalbyn tomorrow for lunch so that should give it a good run. 

[StinkyPete]

 

[Langers]

108km round trip with a mixture of windy country roads, freeway and lumpy 3rd rate goat tracks covered with a patchwork of bitumen that makes up an increasing percentage of our non-urban road network here in SA.
No discernable issues, the Honda ran as all Hondas do (mostly), smoothly and reliably. I suspect there might be some hiccups if the fuel gauge level drops below 2 bars, possibly with cavitation so I might revisit the installation a bit later on - I've kept the plastic bucket and stainless steel for that purpose.
In summary, not a particularly difficult job, it cost $181 Aus and realistically would take 1 to 2 hours. The important bit is to get the fuel level down so there's nothing in the top tank. I got down to 57km left according to the dash readout and when I opened the bottom tank it seemed about 1/2 full. I'm guessing but I reckon if I got a service centre to do the job I'd be looking at say $350 including parts. I've printed out the detailed instructions written by a US ST owner which I can post if anyone wants a copy.
Cheers ... Mark

[Shiney]

Awesome work Langers
Please do post the instructions along with any notes you have from your install in the "How To..." section

http://ozstoc.com/index.php?board=52.0


Cheers
Shiney

[Langers]

  Done

Cheers ... Mark