My 82 Seca turbo--a few pics

Hello everyone--Just thought I'd introduce myself here and post a few pics also. I can't believe I didn't find this forum a long time ago, and I'm glad I did. I never knew there were so many people who are in love with these XJ powered bikes! I've had the turbo for quite a few years now, and even though it's the most problem ridden bike i've ever owned I just can't get enough of it! The other XJ is a 81 Seca 750 with a 650 motor and headlight/gauges. I've had several XJ bikes over the years and this bike was the result of extra parts laying around being thrown together to make a running bike. The bike looks alright in the before picture, but believe me it was a disaster!
This looks like a great community, I'm glad I found it and hope to help out as much as I can! -Nick





BEFORE


AFTER

 

Welcome Nick.... Interesting that someone put a 650 in a 750 frame, most people do the opposite

 

Nice Job. There is a bike like that a few houses down from me that's been sitting in the back yard for a few years. I've been thinking about asking what I could get it for.

 

I see you like blue! :lol:

Nice looking bikes!

You say you have had the turbo a long time, and had a few problems with it? Maybe you could give me some advice for my re-new to me turbo?

Welcome to the forum, and have a look around. There is a lot af great information, and people, here.

Jim 8)

 

Thanks guys....yes, the turbo can be a headache at times, usually fuel related. The issue I've been having lately is it falls on it's face at 6000 rpm and it pops and cracks pretty loud, I know it's not getting enough fuel when the boost comes on and it's running super lean. The FPR seems to be in good working order, no kinks in the fuel lines, carbs are synchronized.....and it happens sometimes, not all the time. Sometimes at low to mid throttle it seems like it misses a little, like the pilot jets are dirty. I've had the carbs on and off so many times I can do it in my sleep. But when it runs correctly, it runs like a champ! I keep hoping something obvious is going to smack me in the face and the bike will run great all year long! I've read that people have colortuned the turbo....I didn't know you could adjust the air/fuel mix on these carbs. I'd be glad to help you as much as I can Jim if you need it. The older these bikes get, the more problems keep popping up. The 750 Seca has a 650 in it because the previous motor had severe crank and cam bearing failure due to the idiot previous owner. I had a 650 maxim that was involved in a accident (T-boned someone pulling out in front of them) and the motor was still good. So that bike is the result of alot of parts swapping....it's a bit underpowered for sure!

-Nick

 

Nice job. I'm hoping to have my Turbo back together this summer - slowly but surely....

 

Jim try replacing the spark plugs. I did that in mine and all of the sudden she is running like a top

 

Plugs are new and clean.

Essentially mine feels like it starves out of fuel and dies after about 20 miles. Then, a couple minutes later it starts up and runs fine all over for another 20 miles. Oddly, the boost guage is the first indication of an issue as it begins to bounce around and boost earlier than normal. It has done it a couple times.


Jim 8)

 

sounds like fuel starvation. My boost guage will do the same. Could it be a plugged fuel filter?? you are running a fuel filter right? if not then it might be time to take apart the fuel pump and possibly the carbs again.
Could also be a vacuum building up in the gas tank. You need to take the fuel cap off and completely dissasemble the fuel cap until you get to a cork gasket. Leave cork gasket in trash can and reassemble. Some of us have also just drilled a 1/16th dia hole in the top of the gas cap to help vent the gas tank. Yup they can be a pain but when they run, the turbo's like to be run all the time.
sean

 

What about the float level? Set to low and the bowls only fill part of the way. Could this be a possibility?

 

Definitely running a filter, and the bike runs like stink when not starving out.

The vacuum in the fuel tank idea makes a lot of sense. When it dies, and sits for a few minutes, it starts up and runs fine again. This has ONLY happened on the freeway, never doing an hour around town.

I think you may have hit it in the head!

I'm going to go out for a ride and test this idea!

Thanks for the input! I REALLY appreciate it!

Jim 8)

 

Is that a normally aspirated Seca engine i see on the right? Tell me it's at LEAST a 750, and preferably a 900.

 

Nope they are both turbo 650's. He had his exhaust ceramic coated I think.

Sean

 

Hey Jim, did removing the cork do the trick? Same thing happened to me once also....took me awhile to figure that one out.

 

I only managed thirty freeway miles so far, but no sign of an issue. I'm going to try it again tomorrow and see.

<crossing fingers>

Thanks,

Jim 8)

 

Great shots, XJTurbo - great username, too!

It's great to see all the fellow boost brothers here online. This place is a real blessing for those of us stuck in the past.

I love my bike, but it is definitely a learning experience. I recently go the Yamaha factory manual for the LJ & LK bikes. It's called a supplement and bound with a G model basic manual for the shared mechanical parts.
The diagrams about the turbo design are really great! These bike are a ton of fun when they are running right.

 

welcome xlturbo, sweet looking bikes, mine is doing the same as yours, poping and cracking from what sounds like to be from the carbs, but i think i have finally traced the problem to the vaccum port going to the top of the carbs where its there the vacuum is used to push the slid up, mine was just slightl obstructed, but, well see tomorrow when i put them both back together. ive got too many projects now, lol. just got 2 more, 2 cx 500's. man, and all i really want is an fj1100 or 1200, lol. just cant seem to find one cheap enough. oh and i like the blue on your turbo, all ive ever seen is silver. well, glad to meet you, and i see a bunch of other new turbo guys, welcome to the turbo cult, lol.

 

Thanks guys, glad to see I'm not the only turbo freak out there! Mine has been running perfect the last two weeks....the last problem was a combination of little fine rust particles getting past my fuel filter into the carbs and not enough fuel pressure....problem solved and she's keeping up with the R1's again! Hope you have figured out your problem there boostedsupra, let us know how it works for ya
-Nick

 

Hey Nick, I had the same issue on all my Secas.

Most likely the vacuum issue to the tank, but also be sure to check the conical factory inline fuel filter that sits inside the intake to the fuel pump.

Also sometimes the intank filters clog up, if they havnt fallen off yet

-Steve

 

Hi Steve--taking out the rotted cork gasket in my cap made an immediate difference. I took the in-tank filter off because it didn't want to stay on the brass tube that sticks up off the petcock. It only has a 3/8 see-thru filter between the petcock and pump now....seems to be enough. I adjusted my valves today and had enough correct shims from another parts bike to get it done. Damn, does that make a big difference!! 2 intake and 2 exhaust valves were .5 mm under the minimum....which I'm thinking is because instead of the cam lobe wearing, the valve seat must be wearing putting the valve shim closer to the cam lobe? Anywhoo, the bike runs most excellent now and i'm quite happy with it!

-Nick