Simmy's Naked Turbo Project

I finally stopped feeling sorry for myself and got at the carb removal.
It took me about 2 hours to get the carbs on the bench and #1 isolated.
The fuel pump, fuel regulator, battery box, air filter, surge tank all have to be removed.
So far I removed the idle jet and blew it through with air. Its possible it was plugged since a small grain of dirt is seemingly all it would take.
I really don't want to be removing them after this time.
Does anyone have any suggestions what I can do to positively ensure the idle passages are clear on this carb?

 

Remove all rubber seals and soak in Berryman's Carb Dip for 2 hours,

Alternatively (and less certainly) blast the hell out of the idle circuit with your favorite carb cleaner.

 

When the carb cleaner shoots you in the eye you know the passage is clear.

 

Vapor blast Canada guy here in Chilliwack uses glass beads. I think that’s why the carbs look like new as the beads polish the aluminum.

 

I tried finding this Berryman’s stuff about a year ago, nobody seems to sell it in Canada.

 

Just had a look and Amazon.ca has it at a BIG price 127$
Or autozone for $29.99
I’ll have the in-laws pick up a can in Bellingham for me.

 

ya I suspect that is what was used, he told me to rinse and blow them real good.

 

nice, do you know if it will tarnish the beautiful finish it has now?

 

As far as I can remember we used that many years ago in the shop and never had a problem.

 

Only if you let it sit for too long. An overnight soak will make it look like it was anodized grey, but the finish might not be even.

 

Also be aware that there are 2 different versions of Berryman's; seemingly like everything else in the modern world, there's the original "good" stuff (deemed too dangerous for mere mortals) and the modern, water-downed "safe" version that does a piss-poor job, but it saves the whales, etc. You might want to contact Berryman's to know how to recognize the "old from the new". The "old" formula is the good stuff.

https://www.berrymanproducts.com/products/cleaning-degreasing

 

The new stuff is the only formula that can be sold in California, but it still does a good job. It just takes an extra dip sometimes.

 

Autozone are no where near me. I see the Amazon.ca price, no way I'm paying that.
I saw a video of a guy in the US saying he bought the Berryman's at Walmart for $17.
I'm going to stew it in Pinesol for an hour, blow it and spray it with carb cleaner, then repeat.
Maybe blast it myself with baking soda afterwards. Its just one carb so I can hand polish the exterior if I have to.

 

I stripped #1 carb body yesterday and stewed it 30 minutes in my ultrasound tank at 50C, 50/50 Pine-sol & water.
I blew it out, sprayed carb cleaner through every passage, then repeated this process 2 more times.
Unfortunately even Pine-sol made the aluminum black.
I tried blasting it with baking soda but wasn't getting a good result so I took it to the bike shop with vapour blasting.
$20 cash and 15 minutes later it was looking all new and sparkly again.
I put the rack back together and they're back on the bike.
I learned something remounting the carbs.
First I applied the smallest amount of grease on the rubber manifolds and stabbed #4 as far as it would go.
It was obviously not completely seated because the other 3 were still not home but it was already in past the groove.
I tightened #4 clamp anyway then pushed hard on #1. They all popped in.
I undid #4 again, made sure it was squared up then tightened them all.
I had them installed in under 2 minutes.
I'm a carb mounting hero! In my own mind anyway, LOL.
Hoping to get more time this weekend to remount the fuel pump, surge tank, air filter and battery box and continue with the tuning.

 

Jukebox hero popped in my head immediately, and I can't get rid of it now.

 

I got all 4 firing, settled on 2-3/4 turns out on the mixture screws and an even synch across the bank.
I took it out for another spin around the neighborhood. After the first spin around the block it was running real good but the idle settled a little high, this is to be expected.
I took a few more laps then it started stumbling like it was low on fuel, which it was.
I put some fresh gas in but the running condition did not improve. Taking a break from this thing for now.

 

It's good to take a break from this project. If you are like me the answer to the problem will come to you in the middle of the night and wake you from a dead sleep. I know you won't give up.

 

I assume you're using the pressurized fuel system from the Turbo Seca. I had a problem with mine that took a while to trace where the check valve o-ring got stuck or glued to the seat. Fuel could still slip through, so if the fuel pump ran long enough or it sat for a while, the carb bowls could fill with fuel eventually. That that would make it run well for a little while, but as soon as you took it up to highway speeds and were consuming fuel at a good clip, it would stumble, sputter, and eventually lean out and run on only 1 or 2 cylinders (likely which ever would fill first through the fuel rail.

To test this, drain a carb bowl (you can try all of them to rule out a float valve). Then do a "wet set" float height measurement. You're not trying to get this exact (I had better luck setting up the carbs on a stand with the whole fuel system connected for that) but to make sure that 1. your carbs are actually filling but not overfilling and flooding the engine, and 2. that they fill "quickly." If they seem at all sluggish to refill, I would suspect part of the fuel system.

In order to fill your carbs, you need to run the fuel pump. On the Turbo harness, this can be done one of two ways, either ground the "test plug" which came out of the left hand fairing on the stock Turbo seca and was a female bullet connector. The other way, if you have the safety circuit installed, is to put the bike in first gear, kick-stand down, ignition on, and try to start it. You'll hear the fuel pump run, but the engine won't turn over. The only downside is that power is removed from the dash, which is where my fuel pressure gauge was installed.

I had installed a Glow Shift fuel pressure sensor and gauge, it was the cheapest at a little over $100. With that, I could verify that the fuel system had pressure when running. This led me to the check valve (eventually). Like you've discovered, the intake books on the Turbo are more stiff than the naturally aspirated ones, so removing and reinstalling the carbs is a pain (and I'm sure I had done it dozens of times on my turbo, using the "clamp one end" technique you described). A couple of months ago I did discover that you can access the check valve without removing the carbs if you have good pliers for removing the hose clamps. You'll have to remove it to disassemble, as the screw heads face downwards.

 

Thanks @ManBot13 your input and experience is great to read.
Lots to unpack in what you’ve wrote.
The only mechanical changes I’ve made is the upgraded fuel pump, boost controller and elimination of the bank angle sensor.

Everything else has been cosmetic.
I rebuilt the fuel check valve with new o-ring but it could be sticking. Anytime I’ve been above 5000 rpm it does run really strong but I haven’t had it on the highway for any extended running up there.
The check valve is easily accessible, not too difficult to inspect.
Anytime I’ve drained the carbs they were full.
I’m not aware of the test plug you mentioned on the left side of the bike.
There’s a female bullet connector at the TCI I’ve not understood it’s purpose.

 

I took the check valve apart today and everything looked just as it had when I last assembled it.
I'm focusing now on the fuel pressure regulator. I think it could be stuck open.
If that is the case it won't build enough pressure to open the check valve and all fuel will return to the tank.
The check valve needs 2.8 psi fuel pressure to open.

 

I'm going to order a fuel pressure gauge and tee this into the system to see what's going on.
Even if I resort to installing an aftermarket FPR I'll need the gauge to adjust it anyway.

That is a nice tip and should save wear'n tear on my starter motor.
It's not getting fuel, I'm convinced of that now.
The only time it fires now is when it sits for a length of time but then just fires briefly.
I suppose I could remove the internals from the check valve to see if it runs.
I need a gauge.

 

I bought a cheap pressure testing kit for fuel injection systems.
Unfortunately the gauge reads 0-100 psi, I had my doubts of its accuracy trying to read 2.8 psi which is the pressure needed to trigger the check valve.
I used @ManBot13 trick of putting the bike in gear with the sidestand down to activate just the fuel pump without the starter motor, worked like a charm.
With just the pump running it would just bump the needle on the gauge when starting but then read zero. Same result with the motor running.
I'm going to replace the gauge with one reading 0-30 psi to get a more accurate reading of this.
I plugged the fuel return line after the regulator just to see what the new pump will do.
As the pic verifies this pump is good for 22 psi so this was a good choice.

 

I know you mentioned not wanting more gauges, but if you change your mind, this is what I have (and it's gone down in price, $85) Glowshift. I used some brass fittings, a 3-way pipe threaded "T" with two barbed ends and threaded the gauge to the third opening. You need fuel resistant thread sealant as well. The only downside is that the gauge is not very bright, but you can change it's colors! It works really well if it's next to a boost gauge with the same range (0-30psi).

 

Yes once I have this dialed in I plan to remove the boost gauge (& fuel) anyway, blurred scenery is the best indication it's working correctly.
I looked at the Glowshift stuff last night. If I still had that barge of a fairing I'd love to run all these gauges.
@ManBot13 when you ran the pump what pressure did you see? Also at engine idle what did your fuel pressure read?
I ordered a 0-15 psi gauge last night so I should see exactly what I'm getting. Should it read 2.8 psi or will it be something less?
Currently the 0-100 needle just blips when I activate the pump but still rests at zero with the pump running.
I suspect the regulator is not holding any pressure.

 

So I never actually saw the fuel pressure when running the pump alone, since there's a diode that cuts power to the headlight and dash when turning over the engine. That causes the gauge to reset since it's electronic. That's why I mentioned the above "downside."

I can say, that while the engine is running, the fuel gauge would show 2psi (at idle/no boost). Sometimes a little higher, but always between 2-3 psi until boost kicked on. I had it connected to the fuel line from the check valve to the pressure regulator. I'm not quite sure where it's connected in your setup, but you want it to sense the fuel pressure that the check valve sees. I don't think the check valve actually actuates at 2.8psi, I think it opens earlier than that, and that the float valves can contribute to the "back pressure" that opens the fuel pressure regulator.

Also, note that if you forget to open the fuel valve, the fuel pressure would drop to zero before the engine dies.

 

I have the fuel gauge teed in between the pump and the check valve but it shouldn't make any difference if its between the check valve and the regulator.
The regulator should keep everything under pressure back to the pump outlet. The check valve is teed so passes fluid through anyway, pressure will be the same on either side of it.
As stated my current gauge is too wide of scale but its reading 0 with the engine running. The bike will be starving for fuel if that is the case and symptoms seem to support that.
I'll be waiting a week or 2 for the 0-15 psi gauge to arrive. If it does not read at least 2 psi I'll be replacing the regulator.
I've attached the schematic if there is anyone else interested in following this conversation.

 

I agree with your setup just though it would be prudent to ask. You’re likely on the right track with the regulator.

I was always worried what might happen if that regulator failed. What aftermarket regulator would you get?

 

this one
https://www.holley.com/products/fue...regulators/carbureted_regulators/parts/12-887

I read on the turbo forum another guy used it. Its adjustable between 4.5-9 psi but the poster said he was able to adjust it down to the 3 psi range needed.
I did my own research, called up the listing on Summit Racing, plugged in the criteria and this was the cheapest one checking all the boxes.
Another one appears to be the same thing only chrome.
https://www.holley.com/products/fue...regulators/carbureted_regulators/parts/12-881

It first puzzled me what to do with the outlet port but this would just get plugged if it was mounted in the same place as the OEM schematic I showed above.
It could be mounted before the check valve (which is a more conventional automotive configuration) but then you would need to cap the output on the check valve, same difference.

Nothing I've found is as compact as the OEM Yamaha FPR so the routing would likely need to be reconfigured once a suitable place to hide it is determined.
I don't want to go this route but if it solves my issues, I'll have to. If I go down this path I'll probably replace the check valve with an electronic solenoid valve triggered by the fuel pump circuit.
There are probably 1,000 different model specific FPR's in the automotive world that look like the Yamaha but of course they don't list the specs, they are not adjustable, and they are set up for fuel injection with much higher pressures.

 

i looked up my bmw k11rs, it's fpr is 68psi and pump is 36 psi. so there's one you can eliminate

 

this place looks promising
https://fuelab.com/fuel-pressure-regulators-low-pressure-applications/

 

thanks @Polock I saw those, they do specify the correct range.
Would be nice to see their physical dimensions.
$175 bucks!

 

found a drawing.
https://www.jegs.com/InstallationInstructions/0/083/083-525series.pdf

this could probably fit under the carbs on the RH side next to the starter motor.

 

the more narrow reading pressure gauge arrived.
The good news is the fuel pressure regulator is holding the pressure exactly where it needs to be, 2.8 psi.
The next plan is to strip the innards from the check valve and see how it runs any better.

 

@ManBot13 you were spot on with this.
I first took the check valve apart 2 months ago to inspect it when I read your reply.
I had just rebuilt it with a new o-ring so I assumed it was functioning properly, pretty simple device right.
I spent about 1/2 an hour in the garage today with the mercury stick and it was running and idling perfect.
I took it around the block and after a couple laps it started sputtering again.
I limped back home and just made it into the garage on 2 cylinders.
I was beyond disappointed, it was running so good for about 10 minutes.
I completely removed the innards from the check valve.
BINGO! The bike is running perfectly. Absolutely perfect, like as in absolutely no issues.
I headed out on the expressway and had a good straight section at speed.
I haven't actually set the boost controller yet, I set the spring preload what I thought was a soft setting but I read 14 psi on the boost gauge today. The cheap gauge bounces all over but once it pressures up to 10 psi the needle becomes solid and steady and it climbs pretty quick to 14 psi. I went for another spin with a buddy on his GSF1250 so I got a few more opportunities to crank it up. The boost controller is definitely set at 14 psi as that was the limit today. Even that is crazy illegal but man is it intoxicating, you just want to keep accelerating. I need to play with the boost controller a bit, see if I can adjust it lower and get the proper feedback on the gauge before going over 14. Its possible the wastegate is staying closed and the BOV on the surge tank is limiting things, but as I said there is very little preload on the boost controller spring. I did slip a washer into the BOV so it should stay closed way beyond 14 psi as I think that's about where the OEM spring is set to open.
Now I can focus on getting it painted over the winter, and flipping the brake discs around, oops!
2021 is going to be fun as long as I see no tickets on this thing.
I'll be 60 in the spring. I had a brand new Seca Turbo in 1984 and almost lost my license then, I had a drawer full of tickets, cops then had a tendency to knock your ticket down to 15 kph over so you wouldn't see demerit points.
I worried about demerit points but my insurance company freaked out at the number of infractions.
I'm much more responsible today, age makes you much wiser for sure.

 

Super glad to help! That issue literally took me two years to diagnose, so you’re doing better than me!

 

Even with miss matched paint the bike looks good.

 

Thanks @lostboy I’m going to contact your body guy again and get the painting underway. It’s really running great, I’m so stoked.

 

Simmy, I just went a private message to you——-
Dfox

 

What color do you have in mind for it?

Tony

 

This has been a very well thought-through build

 

top secret for now. It will look like Yamaha did it.

thank you Sir, I would love to show it off at one of your carb clinics.

 

It would be GREAT!!!!!

 

Casually scrolling through this thread and I just had a blast of serotonin seeing these 4 engines lined up and a nice laugh "R&D labs" awesome lol

 

Hey @Simmy , question for you - where did yamaha hide the turbo? Is it directly underneath the swingarm pivots?
The 900F framy project has a surprisingly roomy space here, and also another above the pivot points, although this would rob some of the battery/ecu/charge-cooler space. This is the problem with these kinds of projects, the edges keep shifting. I have a 650 turbo engine, so could mount it high or low really, assuming I want to double the size of the project...

 

This shows it behind the collector https://www.yamahapartshouse.com/oemparts/a/yam/50042383f8700209bc787a70/exhaust

 

Thanks. That's interesting - looks like they used ane muffler for the turbine outlet and one for the waste-gate

 

Not sure about that. Look at where the bolt #14 lines up with the exhaust flange and something hidden on the turbo. Perhaps a more detailed set of pictures of that turbo would answer questions.

 

Confirmed - from the write up @Simmy posted up from back in the day.
https://badcurator.org/resources/Magazines/CG_Sep82/Yamaha-XJ650-Turbo.pdf

 

Hi @Minimutly if you go back to Page 9 in this thread I took a shot of the turbo installed without the swingarm in the way.
I showed the comparison to the standard 650 frame, the centre stand pedestals are too tightly spaced to accommodate it.
I'm not sure how the 900 frame compares.
The biggest problem with mounting the turbo here is it becomes the lowest point in the oil circuit.
Yamaha installed a check valve in the oil line to the turbo to prevent oil from flooding it.
Some have found this defective, mine was working, however I found the scavenge line was leaking oil back into the turbo unit.
I believe the swiping surfaces in the pump itself leak and allow the oil to seep. This is why I installed another check valve in the scavenge line.