Progress on my Turbo

Finally, yesterday I was able to spend most of a day working on my 'new' turbo.

Most things are very encouraging.

First I drained the oil. The old oil looked fine. In fact, I'm sure it didn't need changing. It must have been changed very recently.

Next, I pulled the check valve to the right (looking from the front) of the oil filter cover. I've read about problems caused by a stuck check valve. I'm hoping that this is the valve reffered to. It looked fine. It operated fine. I could detect no signs of wear at all.

I had been deeply concerned by lots of goo on the front rotors. I was convinced that there was a leak in one of the calipers. So, I drained the system completely, removed the calipers and cleaned the rotors. After cleaning the calipers, cleaning the pads, re-installing everything and bleeding the system, I can't detect any hint of a leak. I'm now thinking that they were just greasy from being in a bad environment. I supose there could be a leaky fork seal, but I see no indication of a leak. Of course, I guess the forks could just be completley dry!

I had noticed that there was a fuel leak somewhere. A little detective work and I found that there are a few issues in the fuel system. At some point, someone installed an in-line fuel filter after the petcock. I don't really see a problem with this, so I replaced it with a new one. I discovered when I removed it that the fuel hose was in really bad shape. I replaced that all the way to the fuel pump.

I discovered one seriously bad thing in the fuel system though. With the petcock set to 'Off' there's still a significant flow of gas. The bike has always seemed to be flooded when trying to start it and I'm guessing this is the reason. Am I correct in assuming that no fuel should flow when the petcock is set to off? I'd love to rebuild the petcock. Does anyone know of a source for a kit of seals and o rings?

After doing these things, I fired it up and it does seem to run well. There are some issues though. It's hard to start. I think this is being caused by a number of things. I think the battery needs to be replaced and it just doesn't have enough juice. I also think the bike is flooded due to the leaky petcock.

Once running, the bike needs to warm up before you can give it any gas at all or it will stall immediately. Again, maybe due to the petcock.

Once it's warmed up, the engine runs very strong. I think the carbs need tuned, but I have neither a yics or synch tool. I hope to get both soon.

The biggest concern is that there is a lot of white smoke. I fear that the turbo may be leaking. I took a closer look at the trubo and tried to clean whatever I could. The assembly looks good, but who knows what the seals look like. I was going to remove some parts and inpect them, but it seems that every nut and bolt is fused together with rust. I will work on this more as time permits.

One more thing to mention is that it was really, really cold when I was working on the bike. Like 20 degrees. I think this may account for some of the white smoke. I fired up my XJ650RJ for a short while in order to move it. I noticed that it was blowing some white smoke as well. I've not seen this before so I'm thinking the cold at least accounted for some of it.

Anyone have any comments on any of this?

Thanks,

Greg

 

These bikes are very poor starters, you will just have to get used to this. They need a LOT of cranking when cold, or if left off. I believe waiting a short while before turning on the key and cranking it over helps a bit (allowing fuel pressure to build?), but starting this bike when others are around is a bit of an embarrassment due to all the winding over it does. I assume it's from the low compression. Don't be surprised if your starter motor bearings squeal once in awhile. I took my starter apart last fall and regreased the planetary gears, cleaned out the dust from the brushes (a lot), and put a small dab of grease in the bushings for the planetary idler gears and motor shaft. A SMALL amount, since any exposed grease will suck up dust from the brushes like a swiffer broom. Leaky petcocks are a common fault as well, but a rebuild kit is available from Parts N More. Applicable o-rings are likely available locally at a much lower price if you are so inclined to go to a hydraulic supply shop and get them sized. You'll need something gasoline resistant though. Viton seems to be an effective material for this. Personally, I'd just ante up for the rebuild kit as you are likely to need the gasket as well as the o-rings and the counter man at any hydraulic supply shop is bound to be unenthusiastic about digging through his stock for a $2 sale.

These bikes commonly burn some oil after sitting for awhile. How much is normal, and how much indicates seal failure is open to debate. Usually, if it burns off within a few minutes of riding, you're good to go, but if it is persistent, likely the seals are bad, or the check valve on the oil feed tube is bad, allowing the turbocharger to flood with oil when the engine is shut off.

The seals are well inside the turbo unit and require complete disassmbly of the turbo to inspect or replace. This is not something within the scope of most home mechanics' abilities. Any turbo once disassembled will need to be rebalanced. Not to say that there's nobody on the board capable of doing this, but it is certainly something beyond my ability.


If You're Feeling Brave!

 

Mac, you mentione the check valve on the oil feed tube. Is this the valve that is to the right of the oil filter case (looking from the front.) It seems to be connected to a tube that goes back to the turbo. I checked that valve and it's fine. Looks and operates good as new. I just want to be sure I'm checking the right thing.

Thanks,

Greg

 

Thats the one. Nothing much to go wrong if the oil isn't severely sludgy.