There you go problem solved, not that there really was a problem. I picked the last 1/4" Bspt  Allen plug in the area. Picked up some stainless plate for the brackets,I now need to order a clinometer, and a boost gauge. Feeling a bit slack today so I might just paint it and do the brackets on Friday.
Regards Martin.

would it make sense that a temperature gauge could be fitted ??  or is that just being silly ????

Charlie I thought about fitting a temperature gauge but I couldn't find one that fitted in. I do however have a laser temperature gun and have been recording fuel rail and tank temperatures. Unfortunately since I have started recording we haven't had any real scorchers. I am going to hook it up at first so I can easily take the cooler in and out of line. If I carry my temperature gauge I should be able to get some sort of data on the cooler.
Regards Martin.

perhaps just tank temps would  be a good standard martin

I know my tank temps went from in the high 50s -low 60s down to ambient air temperatures , with my implementation

not sure that the available btu cooling effects of air along the cooler at an oblique angle , and behind a fairing structure will make a lot of difference , all of the time .

but at a minimum will make some difference


looking forward to see some results as they come in

good experimenting indeed ...enjoy

Where it is situated it does get air flow from forward motion and air off the fan when stationary. I also have room to mill fins into the back of it, if needed. I might even do that anyway to see if it further reduces temperatures. If it doesn't work there is always cooler MK2 in the wings.
Regards Martin.

"I do however have a laser temperature gun..."

Why don't you mount a leather holster using that spare hole so you can take the gun with you when riding?

I bet that'll get 'em talking!

I could do that, but I have a slight aversion to being shot at, and I don't like prison food.
Regards Martin.

After a lot of head scratching I decided not to mount the cooler off the stainless steel bar that runs across the front of the throttle bodies. The bolts are only 5mm and if mounted flush to the rail impede access to the vacuum ports. I was going to try heavy Velcro, so I had a look at what Bunnings had to offer and found something that has heaps more grip. Had a bit of stuffing around routing the hoses, eventually got something that worked. The return hose has not been altered in length and therefore the cooler can be taken out of the circuit at anytime. Even though the new type of Velcro is extremely good I added a safety strap as a precaution. I had a minor fuel weep on start up from one off the Allen plugs just required a minor nip up. The only problem was the paint which although drying for two days is still tacky, could have been the humidity. I will have to strip it and repaint at some stage. We are coming up to some hot days so I will take the laser temp gun with me and try and get some readings.
Regards Martin.

Bricks been playing up, battery going flat and running rough intermittently. A new regulator fixed the charging problem. I did a short run a mx of 60 and 80 KPH roads, and when I got home I checked the inlet versus the outlet temperature. Todays temperature was 29 deg the  comparison revealed a 4-5 deg drop. I'm not sure that is enough to cure the vaporization problem until I see what happens in traffic on a hot day. Further modification to the back of the cooler by milling more fins may reduce the temperature further. I will not be able to access the mill until early next year. In the meantime I will continue to monitor the temperatures. I don't have the time at the moment to chase the rough running and misfire, I need to do temperature reading on the header pipes, which requires removing the belly pan.
Regards Martin.

4-5C isn't bad.  Be aware that the cooling will increase as the approach temperature increases.  The hotter the fuel gets the more cooling you get.

MartinW wrote:Bricks been playing up, . . . running rough intermittently. . . . the rough running and misfire . . .

Did this performance issue exist before the cooler's installation?

No Laitch I suspect one of the injectors, it is intermittent, occasionally running fine. However the Honourable Ministers is flying down to Victoria to visit our son his partner and our newly arrived granddaughter. At the moment I don't have anytime to diagnose the Brick. We are having our Christmas day today with the rest of my family. Spent most of yesterday with the Lamborghini and whipper snipper doing edges and hedges. The Minister is gone for two weeks as of the 22 nd of Dec, the two daughters gave her a airline ticket for her birthday. I will then have time to properly diagnose it.
Regards Martin.

Laitch wrote:

MartinW wrote:Bricks been playing up, . . . running rough intermittently. . . . the rough running and misfire . . .

Did this performance issue exist before the cooler's installation?

Because you answered "No", if it were my bike I'd bypass the cooler and take it for a nice warm ride to see if it acts up. Turbulence or obstruction within it might be causing problems.

It was -2ºF here this morning, but it has been a beautiful windless day.

Thanks Laitch bypassing the cooler is on my list, but I have already blown it out. As all the galleries are 10mm I don't believe it is restricted, but weird things can and do happen. I've already changed the spark plugs, so my next step will be to take it for a ride without the cooler and belly pan and if it's still playing up check the header temperatures. I have spare injectors and access to other parts if I have to do the replacement test. This is the first time in twenty years that it has given me trouble aside from the two temp sender faults. But it has always got me home.
Merry Pre Christmas and a Happy New Year.

How is that darn four pin fuel tank connector???   Did you remove the tank to install the cooler?  

One of the problems I had with the connector on my RS was intermittant hesitation and stumbling when the connection wasn't bad enough to kill the engine entirely.  Vibrations from the engine and road probably caused the problem.

I had to crimp the female connectors a bit to get a better connection.

Thanks Gryph I'll add that to the list to check. I might be able to get onto it on Monday.
Regards Martin.

Good luck!

I went for a test ride minus the belly pan. It was still occasionally misfiring but would still manage to get up to speed I clocked 140 Kph and still accelerating. Put the temperature gauge on the headers all even, pulled the plugs and they were black sooty and dry. Check the spark intensity which was good. Removed the cooler to take it out of the equation, then tried to start it. It would fire and try to run but after a few tries it would not even cough.  

Listened for the fuel pump but I couldn't hear it, so I disconnected the fuel line and placed it in a container to be sure. No fuel flow so I went straight to the 4 pin connector and found no power. Went to the fuse and no power, popped the tank up and pulled the relay. Which tested as faulty so I replaced it with an old scungy one that tested OK and the pump sprang to life.

This whole saga was a bit strange normally relays either go or don't go? And why did it start to fail after I had just fitted the cooler? Also to add to the slight confusion was the alternator playing up and failing to charge. The battery is still not as good as it used to be so it maybe getting replaced.  I did however learn a bit more about fault finding, go step by step and follow the logical path even if it doesn't seem logical at time.  And follow the K bike flow chart.
 
I am going to have to wait until the honourable Minister gets home so I can go and get a new relay. And hopefully it will now behave itself. however it is the original relay.
Regards Martin.

I ended up with a 40 amp relay from the local Repco. I fitted it and it fired right up, battery is still not real good so I'm going to charge it overnight. I will give it a run tomorrow before I refit the cooler and put it fully back together. Sometime during the week I'll order another battery probably a DynaVolt as Revplus don't make the one that suits the Brick anymore. I did look at Motobatt but found a couple of articles saying that the quality has dropped and they now used recycled lead in their batteries.
Regards Martin.

the fuel relay really doesn't only control the pump ..the under seat efi controller as well  and if getting intermittent voltages can really give interesting to say the least, operations

good luck with the battery  and charge system

cheers

Problem solved, but really confusing at times. I am the second owner I've had it for twenty years, as an act of presumed kindness the previous owner had marked all the relays with stick on paper labels. All the small relays were marked incorrectly, so when I was checking what was marked as fuel pump it was actually the horn relay. Inge set me on the correct course, thanks Inge. Now with the relay correctly identified the next problem occurred, the fuel pump relay had been replaced with a Narva relay.

When I got my Brick it came with heaps of goodies and assorted bits which include a relay which I recovered out of my spares. It to had a paper label marked as load shed relay. I was still not sure so I went around to a mates place, he is a Sparky and has a collection of Bricks and parts. He ran a meter over the Narva and the OEM relay marked load shed and confirmed different configurations. Further testing confirmed the Narva relay was occasionally cutting out. The OEM however appeared to be OK but he gave me a spare relay that he had, so the fog is finally lifted.

Rob also came up with a non OEM replacement which can be used with slight modification. With the new OEM relay the Brick fired up I went for a short ride and no missing or cutting out which I am now assuming was caused by the faulty Narva relay. I'll still have to replace the battery as it doesn't seem to be holding it's charge as well as it used to. It is 5-6 years old so I am going to order a Dynavolt,
I was going to try a Mottobat but apparently their quality has fallen off. Thanks to Inge and Rob.
Regards Martin.

Had a busy day up at 0200 am took the Honourable Minister for Finance and Recreation to the airport. First I repainted my fuel cooler and as soon as the shops opened went and picked up my new battery Dynavolt. Fitted the new battery with a bit of stuffing round with the connections 90 deg out. Put the tank back on and went to fire it up and now had a bad 4 pin connector. It rarely plays up it has only happened a couple of times previously. I ran out of DeoxIT a couple of years ago, so I bit the bullet and went down to Jaycar and bought the new DeoxIT two very small cans $30.00 Au and a 4pin waterproof connector $20.00 Au. I was going to change the connector if the DeoxIT didn't work, but it did. I've only used the one tin type the new one has gold protector in the second can. It fixed the problem so I will leave the connector for another time. The paint seems to be drying better this time, but I'll wait till morning before refitting it.
Regards Martin.

yeah good advice to wait a little longer for the paint to dry

good luck

MartinW wrote:This whole saga was a bit strange normally relays either go or don't go?

If only that were true. If a coil wire breaks where it's soldered, good old vibration can give you an infuriating intermittant fault.

True Dai, but I now have a source of relays. Rob has one that requires a wiring plug wire switch https://kisantech.com/mag/h0004.html and I have found  https://www.ebay.com.au/itm/DME-Fuel-Pump-Relay-BMW-E36-E39-E38-E53-X5-Z3-12631711266/252650083537?  A mate who has a  son that's an auto electrician has said a few models of Holden Commodores may have the same relay. If and when I find the particular model I'll post it.
Regards Martin.

MartinW wrote:few models of Holden Commodores

Better grab them quick off the Aussie ones then

Thanks I now have two OEM relays stored in the relay box under the tank.
Regards Martin.

Could it be that the pump noise is always there and being dampened by the full tank.

With the cooler removed the noise disappears.   I've got a pulled shoulder at the moment which I made worse by going for a ride and then fitting the cooler. I'm still trying to work out what's going on I can't work out why the cooler in the line would cause this. At the moment without the cooler and with the same level of fuel it is dead quiet. The galleries in the cooler are 10mm but the 8mm barb fitting could be causing a restriction, might have to drill them out. The only other possible solution may lie in relocating where the return line dumps the fuel. Early next year I will have access to a mill and I could make another cooler with radius turns instead of the right angle ones
Regards a perplexed Martin.

Is it possible there is some resonance in the cooler's mounting?

Regarding turbulance, it's your friend in a heat transfer situation.  Laminar flow can reduce heat transfer by significant amounts.  I doubt there is enough energy in the turbulant flow to make the cooler vibrate.  Possibly the hoses connecting it to the tank. 

Is the cooler cantilevered out by it's mount allowing it to flex the mount?  What does the noise do if the cooler is still in the fuel circuit but not firmly attached to the bike?  If anything, I would suspect engine vibration shaking the cooler and feeding that vibration back into the frame or whatever the cooler is attached to.

The cooler is mounted to the air box with heavy duty mushroom headed Velcro. I do not believe vibration could be transmitted to the frame. I went and got extra fuel so I can play with fuel levels, but changing levels does not really solve the problem. Against the advice of the absent Minister for Finance and Recreation I might have a play with it today. If I can I will try and record the sound and download it. The only thing that I can think might be causing the noise is the cooler is acting as a restriction. This increases the output pressure and this is disturbing the flow in the tank causing a vortex around the pump causing it to suck air. But this sounds a bit like I sense a disturbance in the Force Luke.
I am now going out to refit it which is a pain, literally. I need to find my Light Sabre.
Regards Obi Wan Martin.

It would be a bit of mucking around with hoses, but it would be interesting to see what happens if the cooler is on the return line rather than the pressure line. 

Bill

Bill it is in the return line. However with the aid of my trusty Light Sabre (screwdriver ) the disturbance in the Force been vanquished. I changed the following things I substituted the top right angle cooler fitting for a straight one. Switched over the in and out lines. Rerouted the lines to eliminated any possibility of a kinked line when pushing back the tank in position. This now involved having to loosen the fairing (K75s) in order to tighten the return line hose clamp. On start up the Force was calm and silent. So fellow Jedi what do you think caused the disturbance in the force. It was not Darth Vader.
Regards Obi Wan Martin.

I remembered seeing your pressure gauge in an earlier post, and didn't go back to read the text, assuming a pressure gauge would only be useful in the pressure line. 

Glad to hear all is well.

Bill

the fuel pressure regulator pulses the high pressure line with the port vacuum from the throttle bodies activating it  but I think there may have been a restriction going on , which you have removed by the sound of it , good luck

I have been reading up on these fuel cooler installs and going to go with the aluminum one the first poster used. Will be a good winter project as I have to take the tank off and replace the fuel sender.

Point-Seven-five wrote:Starting a new thread to document the installation of a fuel cooler on my '94 K75RT.

Picked up this cooler on eBay.  Looks pretty nice and has as many fins internally as you see on the outside.  Has a pretty good volume that should give me about 40 seconds of residence time.  Extruded aluminum body looks pretty snazzy and doesn't require any protection from stones and other debris.



Got it here:  https://www.ebay.com/itm/10-Silver-Anodized-Dual-Pass-Transmission-Oil-Cooler-With-Fittings/302141681195?hash=item46590c2e2b:g:78YAAOSwUchaBCAf:rk:10

5/16" hose barbs:  http://www.ebay.com/itm/331396623114?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I am mounting the cooler horizontally below the radiator and in front of the cam chain cover.  Hose connections will be on the left hand side.  The mounting bracket will be bolted to the lower radiator bracket.  I removed the existing flat head screws and the body nuts they screwed into.  Replaced them with 25mm long 6mm bolts with fender washers, lock washers and nuts.  The bracket goes in under the mounting tabs for the fan.  Bolts go from the inside with the nuts outside.



Bracket is approximately 3mm thick stainless steel.  Drawing with dimensions I used to follow.

Got this aluminum cooler. It really is a very solid piece.Will make the bracket, and get both powder-coated in the next month. Already have the fuel quick-disconnects. Thanks for a good idea, and for a great implementation & write-up.

I wouldn't powder coat the heat exchanger.  It's already anodized, and the powder coating will only reduce the amount of cooling you'll get.  Mine has covered a lot of miles and still looks new.

It's been several years now and it's still going strong.  It does a good job of keeping the tank cooler on hot days, and the only time I am aware of it is when someone asks what it is. 

Last, this will only work on the K75 the way I built it because it fits in the space below the radiator where there would be another cylinder on the K100.

Point-Seven-five wrote:Starting a new thread to document the installation of a fuel cooler on my '94 K75RT.

Picked up this cooler on eBay.  Looks pretty nice and has as many fins internally as you see on the outside.  Has a pretty good volume that should give me about 40 seconds of residence time.  Extruded aluminum body looks pretty snazzy and doesn't require any protection from stones and other debris.



Got it here:  https://www.ebay.com/itm/10-Silver-Anodized-Dual-Pass-Transmission-Oil-Cooler-With-Fittings/302141681195?hash=item46590c2e2b:g:78YAAOSwUchaBCAf:rk:10

5/16" hose barbs:  http://www.ebay.com/itm/331396623114?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I am mounting the cooler horizontally below the radiator and in front of the cam chain cover.  Hose connections will be on the left hand side.  The mounting bracket will be bolted to the lower radiator bracket.  I removed the existing flat head screws and the body nuts they screwed into.  Replaced them with 25mm long 6mm bolts with fender washers, lock washers and nuts.  The bracket goes in under the mounting tabs for the fan.  Bolts go from the inside with the nuts outside.



Bracket is approximately 3mm thick stainless steel.  Drawing with dimensions I used to follow.

So I found this particular fuel cooler... Agree that it is a nice piece of quality construction.

Following the bracket diagram. I cut a bracket and put a 25-degree bend on it, as indicated (ISWAGGed the 25 degrees but it turned out to be correct).

However, I am unable to fit the bracket onto my K75 this warm February Sunday here in Northern Virginia grrrr... I have a K75, the OP has a K75, but on my K75, the indicated mounting points on the bottom of the radiator where the fan is connected to the radiator frame are a good 2 inches back / behind the vertical plane of the front of the engine, and not roughly in-line with the plane of the engine 's body, like the OP's picture shows.

To make things work, I'll need an addition to the bracket to form a "Z" shape. Plus, the mounting bracket for the horn will get in the way, which I don't see on the OP's pic.

Are there multiple versions of a K75 frame out there that have led me astray? Or perchance does the picture show a K100?

Did anyone else try this solution since it was posted here?

DadofHedgehog wrote:Are there multiple versions of a K75 frame out  there that have led me astray?  Or perchance does the picture show a K100? Did anyone else try this solution since it was posted here?

The 75RT and the K100 have identical radiators. They are thicker than the one on your K75T, hence .75's comment about mounting the cooler in the space where the K100's cylinder would be. That allows his bracket to work and why you'll need to modify your bracket.

Laitch wrote:

DadofHedgehog wrote:Are there multiple versions of a K75 frame out  there that have led me astray?  Or perchance does the picture show a K100? Did anyone else try this solution since it was posted here?

The 75RT and the K100 have identical radiators. They are thicker than the one on your K75T, hence .75's comment about mounting the cooler in the space where the K100's cylinder would be. That allows his bracket to work and why you'll need to modify your bracket.

AUGHHHH! Sob sob sob ;-)

Yeah ok. That makes everything clear. Not what I was hoping to hear of course, but it's nice to have the world begin to make sense again.

It's still Winter - I have time to adapt the bracket. Appreciate the clarification

As far as I know there are only two types of 75 frames.  The standard one and the RT frame which is to my understanding a K100 frame modified around the head stock area.  The obvious visual differences being it uses the K100 tank and side covers.

TacKler wrote:As far as I know there are only two types of 75 frames.  The standard one and the RT frame which is to my understanding a K100 frame modified around the head stock area.  The obvious visual differences being it uses the K100 tank and side covers.

The two front frame members slope more than a K100 frame to make up for the "missing" cylinder.  And since it's a K100 radiator pushed out at the bottom the radiator hose does not pass through the cam cover like on other Ks.  The K75RT uses a K100 gas tank since it fits inside the retro-fitted K100RT fairing. (The other K75 tanks are slightly slimmer and smaller.)

When I built my cooler I was still a bit of a newbie to bricks, and was not aware of the differences in frame, fairings and radiators.  At the time I built my cooler my only experience was with the K75RT and the 16V K100RS. 

I was using the RT for touring in the summer and found the heat from the fuel to be unbearable on long rides, not to mention the boiling in the tank.  The cooler has worked well for me, but when I looked at using the same one on my K100 and the K75S I found that it would not work on those bikes because of clearance issues between the engine and mudguard on the K100 and the engine fairing on the K75S. I probably should have mentioned that the cooler would only work on the K75RT, but I didn't realize that at the time I wrote up my description.

Since I rarely use more than one tank a day in the K100's the heat is not an issue.  If it was, I would probably go the route of moving the fuel pressure regulator and fuel lines out to the space above the rail and put additional insulation under the tank.  I would also modify the radiator shroud to get more air over those parts as well.  Heck, I might even do it to make moving the tank easier.  Putting the FPR behind the airbox makes almost no sense to me.  It heats the fuel and makes servicing the fuel lines and the pressure regulator a pain.

Point-Seven-five wrote:
Since I rarely use more than one tank a day in the K100's the heat is not an issue.  If it was, I would probably go the route of moving the fuel pressure regulator and fuel lines out to the space above the rail and put additional insulation under the tank.  I would also modify the radiator shroud to get more air over those parts as well.  Heck, I might even do it to make moving the tank easier.  Putting the FPR behind the airbox makes almost no sense to me.  It heats the fuel and makes servicing the fuel lines and the pressure regulator a pain.

or put in some additional blocking foam so that the gills actually vent the radiator heat  before it travels too far back the fuel line etc
im trialling an addition left side vent in the radiator cover to let air pass the hot side of the radiator , after putting in air redirection panels , on the rs im building "fred " so far the redirection has made a significant difference to air  from under tank region ...and noticeable additional heat from the lower fairing gills outside the ankle region

food for thought perhaps

I haven't looked, but I seem to recall that CrazyFrog moved the fuel pressure regulator on one of his bikes.  It seemed like a fairly easy job, the hardest part would probably be getting the fuel pressure regulator out from behind the airbox.  It would be interesting to hear about how it has worked out for him.

https://www.k100-forum.com/t15210-relocating-the-fuel-pressure-regulator

likely a good move , but I recall berts mod actually added a good length of hose to the "behind the panels area " yes far easier to access , but does the additional length add to the heating effect ?   questions to be researched . but we're all different with different ideas ..and environments , but bless the guys willing to try ,,,and report