1982 Yamaha seca turbo fuel pump

I'm restoring an 82 seca turbo. Previous owner said it hasn't been run since the early 90's. I've put a new battery on it (didn't have one when bought), cleaned carbs (did not rebuild yet want to hear it fire before putting to much $ into it), cleaned gas tank, cleaned check valve and blew air through it to ensure working properly all seems fine. I tried soaking the fuel pump in diesel for a few days but when I try to feed gas through it will only very slowly drip out the front. I jumped the leads and saw a spark and might have heard it hum for a second but then nothing. does anyone know how to open these pump up?

 

I've done the same thing! (restoring a turbo that hasn't been run in 20 years)...

I didn't have fuel pump issues, but another member, JeffK, says that an "R6 ('99-'02) pump " will work, and it outputs more pressure than the stock one so you can boost over 12 psi later if you want. I forget the flow rate spec, but it must put out at least 14psi.

Check too that the fuel pressure regulator is working, it's necessary to provide a 2 psi differential (very important to maintain the proper fuel level). I believe I used a hand pump to see when it would crack over and how much pressure it would hold.

How many miles? What's the compression on the motor? Have you checked the valves? If the engine is solid, it'll be a good deal of money and parts to make a Turbo Seca that's been sitting for 20 years road worthy and reliable again but it'll be well worth it!

Jeff also helped me rebuild the turbo itself with a kit from GPop shop. And BDesigns has a bunch of carb kits and exhaust gaskets for the Seca Turbo when you're ready to rebuild.

 

It has 12000 kms compressions is 150, 150, 125, 150 so I know there's something wrong with cylinder 3 but I have a parts motor from another seca turbo so tha won't be a problem for long. The bike should still fire though i would think. I haven't checked valve clearances figured would deal with the fuel delivery issue first and see where I'm at.

Funny you should mention the turbo I removed the exhaust to check for play in the turbo and found the inside of mufflers plugged with rust and the turbo itself looked like there was bird seeds in it. Oil had seeped past the seals into the rubber intake hose and into the collector. I'm trying to take it apart have broken it loose but now it just spins freely but will not come apart. I'm planning on using a press to press the shaft out dunno if anyone has any better ideas? The shaft in the turbo does have some play does anyone know what the spec is for allowed play in the shaft?

 

That weak cylinder might just be the valves, especially if they weren't done before, so check them first. Mine had 6000 miles on it when I bought it, and 7 of 8 valves were tight. Fuel will sort itself out soon enough because if soaking the pump doesn't work you can easily replace it.

My turbo actually got plugged with seeds after I rebuilt it! I left the intake open for a couple weeks while sorting some stuff out and I guess mice thought it'd be a good storage place.

If there is any play radially or laterally it'll need a rebuild. This happens pretty quickly it the turbo is shut off without cooling properly. Oil will get cooked and things will get warped.

Do not just press anything out of the turbo! The "snail shells" come off of the main body, and the shaft is disassembled from there. Don't ham fist the turbo disassembly. It has to be carefully disassembled, realigned, and possibly balanced. The turbo spins at 210,000 rpm, so it needs to be right. JeffK really helped me here. If you aren't sure, it's worth the money to have someone rebuild it for you: G Pop Shop will take care of you there unless you can find something local.

 

The cylinder with low compression could also be the one (there is always one on a multi) that had the valves open during storage. That often leads to stuck piston rings. Dump a few tablespoons of a 50/50 mix of ATF and Acetone down that plug hole. Let it sit for a week, turn the engine over a few times, repeat the process, and then recheck compression at the end of the second week of soaking.

 

I will defiantly check the valves, doesn't take long. If they need to be adjusted is there any 1 brand of shims better than other?

It's the "snail shell" that is stuck on the turbo. It's broken free but just spins now won't come apart so I was going to block the housing and press the nut on the shaft to get it apart don't know how else to do it without damaging the turbine wheel. I'm no mechanic but I'm sure I'll be able to rebuild the turbo with some guidance.

K-moe
Will defiantly try that. Sounds more cost effective than a hone and new rings.

 

Here's a good write-up on a TD04, which is a slightly larger mitsubishi turbo
https://dproberts.files.wordpress.com/2011/09/td04l_rebuild_manual.pdf

My memory is a little fuzzy, but definitely do not hammer the shaft. You need to work it off, using penetrating oil to lubricate. Pounding the shaft will likely deform it

Another link:
http://www.allpar.com/fix/holler/turbo-rebirth.html

A bit part of the rebuild is marking the turbo to make sure you put the parts back in the same place and it's balanced. Mine was component balanced, meaning it should be fine however it's put together, but if the impellers are damaged at all, it may need to be balanced by a shop. Honestly, I feel lucky that I was able to rebuild the turbo completely and that it's worked as well as it does. Much like installing tires, a shade tree mechanic "can" do it, but it may be better to let a professional handle it because of the specialized tools risk of damaging such a rare part.

 

Thanks for the links, will definatly be reading up. I took lots of pictures and made alignment marks.

Didn't plan on using a hammer, was going to use a shop press to avoid damaging the turbine wheel. It must just be carbon build up on the heat shield holding it because the "snail shells" will turn freely. On the other hand I'm a little worried to warp the shaft this is why it's sitting on the bench atm... A new turbo is not a purchase I wand to have to make.

For me half the fun of it is doing the work myself and learning how to do it. I'm new to motorcycles but have been a backyard mechanic for a while. I have always gotten her done. takes a little longer than a pro, definatly more swearing but I do get her done lol.