Hello from PA... Newbie with 81 Seca 750

Just thought I'd say hello. Looks like a great forum. Recently I had a friend give me a 1981 Yamaha Seca 750 that has been sitting in his garage since 2006. Needs some work. Gas tank has rust inside and the front forks are leaking. Luckily there was no rust in the engine and the carbs were run dry before it was put away. I started the bike today using a homemade fuel bottle and fuel line. She started right up and ran great! I did have about a 1/2 lb of dog food shoot out the one exhaust pipe though! LOL I'm sure I will have lots of questions for you guys as I try and make this old bike road worthy again! Thanks in advance!

 

Welcome, looks a nice bike. Bet the p/o had either small children or mice as well as the dog (re: the dog food lol)

You're in the right place to find info to get her up & running again anyway, best bike related forum I've found so far

Couple of points to mention, before you consider a test ride check the links below in my signature regarding rear brake delamination/wheel jamming (especially on a bike that's stood), brake hose age and tyre date codes.

Also, you should still IMO pull the carbs and clean/service them despite it running "great" since these bikes seem to run fine but run EVEN better still when the carbs are "church of clean" clean. Plus you may want to check the jetting suits those exhausts or better, get a set of stock since the bike appears from the pics to be clean & stock apart from those open pipes.

Again welcome, you have a good friend to be given a bike like that

 

Every June I host the Central NY Carb Clinic. It's held just south of Utica, and is about an hour or so north of Binghamton, NY. Easy directions--81N to 12N to my driveway.

If you're interested in attending, PM me. There's other guys that ride up from PA and NJ, too..............

Nice bike!

Welcome aboard,

Dave F

 

welcome man. youre in the right place to get that ride up and running sound, and safe.

 

Thanks for your reply's guys!! Yep I still plan on pulling the carbs to have them gone over and cleaned. Everything has to be gone over before the bike can be ridden. Thanks for letting me know about the links to the brake lines/drum issues 750E-II_29Rbloke! I will check them out for sure.

The exhaust on the bike is actually really quiet and it sounds great. They are not open pipes. I think the exhaust is made by Jardine?

I think that hardest project on this bike is going to be fixing the front forks as I have never worked on forks before. I do have a great service manual that the prev owner gave me so it shouldn't be that bad.

Here's a couple pictures of the front fork seal leak and the rusty gas tank. As you can see the bike is really dirty and needs a good cleaning.

 

Wow is it a complete stainless system then, or are those downpipes just really really nice? If it was mine I'd probably still put at least stock looking mufflers back on since it really does look to be a nice unmolested bike, unusual after 32 years

You'll find the forks easier than you expect, they're really quite simple beasts once you get them apart & as long as they're not bent or pitted it's most likely the seals just dried out with standing. Just remember to keep everything in the right order & put a wrap of electrical tape over the ends of the fork tubes before sliding the new (and rubber greased) seals onto them. There's quite a few different threads on fork seal changes too if you want to research a little & get some better visual clues than the manuals tend to give.


There's a few ways to de-rust the tank, can either try electrolysis, some people use acid-based solutions & there's the old-school method of part filling with diesel & a couple of handfuls of pea-shingle, then shaking it for hours. Personally I think the acid or electrolysis methods are much kinder on an old tank not to mention your arms

 

Welcome. Don't forget to check your valves also. You should probably do it before the carbs. It's really not that hard. http://xjbikes.com/Forums/viewtopic/t=1 ... xj550.html

 

Welcome, excellent score and nice to see another pa 81 Seca 750 getting rescued. Mine was in similar state when I got it and that was 13 years and 18,000 miles ago.

I had a friend replace the fork seals and I know he did fab up a tool to aid in disassembly.

Fuel tank I have cleaned ways, manual method and electrolysis. Manual method I used nuts and bolts plus a bit of kerosene to aid in flushing plus allot of shaking. Manual method does a nice job and will remove surface rust. The electrolysis method does a nice job at removing rust that is embedded into the steel from pitting. To get you up and running I would recommend the manual method.

Consider cleaning the front brake master cylinder and include both calipers as these models have a tendency to drag the front brakes. I would also recommend replacing the front brake lines with stainless steel lines from Len at xj 4-ever, banner / hyperlink is at the top of page.

 

The best How-To for the 750 Seca forks:
http://xjbikes.com/Forums/viewtopic/t=1 ... forks.html

Note that driving out the fork seals can be a challenge if the bushing gets cockeyed. Also, when driving out the seals, DO NOT SLAM the inner fork tube down or you will crush the little wave washers.

I use this method for removing the seals, it's messy but it works.
http://xjbikes.com/Forums/viewtopic/p=2 ... tml#299088

 

Nice seca and welcome ....Lots of awesome folks here .!

 

I actually think it is a stainless system because there is zero pitting anywhere on the exhaust and I would think if it was chrome it would have pitting by now considering how old the bike is.

The previous owner did the front fork seals ounce already but that was many years ago.

 

Man thank you guys for all the advice and the how to links for the forks!!! You guys are awesome!! This truly is an awesome forum!!! I really feel confident now knowing I have all this help if I need it!!! Thanks!

 

Welcome aboard; looks like a bike with great bones. Hope you get her on the road this spring. As everybody else said, You're in the right place. This forum rocks with great guys and better advice.

 

In regard to the exhaust system, it appears to be the stock head pipe/collector box with Jardine "slip ons" replacing the stock mufflers. If so, it's not SS, you just lucked out and got one with solid chrome.

You have a lot of work to do, but it will be worth it. Get a service manual and study up; and take it slow and methodical. That bike has real potential.

 

Thanks guys! Yep I got a real nice service manual with the bike so I should be good. Thanks for the link to the valve adjustment Xjrider92117! Plan on doing that shortly but need to get the tool. Great write up on the valve adjustment bigfitz52!

 

the tool that i prefer is the zip-tie.

I buy 'em by the pack, at Harbor Freight for 99 cents.

dave

 

The tool I was referring about was the one bigfitz52 used to open the valve in order to get the shims out. Here is a picture bigfitz52 posted in the How to thread.

 

Hog was talking about... You really don't need THE TOOL u can use the zip tie method. Which some choose to use I have never but some have and had success. It's up to you. I'm sure you can find something on the site if you look.

 

I'm new to this so I didn't know what Hog was talking about. I'll have to look that up! Thanks

 

Here's something else... Cheers to fitz!!!
I'm sure I've seen others but I think it's really up to the owner to choose.
http://xjbikes.com/Forums/viewtopic/t=29209.html

 

I have two of "the tool" s, but I can pull the shims and check them all in about the same amount of time as it takes to fight with the tool and get ONE shim checked.

Hint: I use TWO zipties taped together. On has the full-length tip on it, the other has about 1/4" or so snipped off. The longer one is curved around more and allows the tip to direct itself right into the valve, the second on curves just inside it and neatly stuffs the opening.

To each his own.................