81 xj550seca build

New guy here. I picked up an 81 xj550seca.

The guy rode it over to me and let me take it for a ride, started right up, idled fine, ran ok, a little lag in the middle of the rpm range. It has a 4-2-1 exhaust and pods so I have to check if it is jetted correctly and tuned, should be fun. Got it for $450. Not sure if it was a good deal or not.

The next day I went to start it, and it took a lot of cranking before the bike started. I wanted to let it run and warm up, but it died after running for about a minute. I was in a hurry, so I didn't get a chance to do anything, gonna try to work on it this weekend to see whats up.

My current plan is to get it to run well, and figure out why I have to squeeze the crap out of the front brake lever to get the bike to stop. I plan on rebuilding the caliper, and replacing the lines with steel braided ones, and see what that does. I also have to replace the lever which is bent. If I am still not happy, I will replace the front rotor with an aftermarket one. That should do it. The rear brake seems ok so I won't touch it yet.

Once I get it running well and stopping well, I will start to make plans as far as what I want to do with it.

I have attached a few pictures of how it looks now.

 

You have to squeeze the crap put of the brake lever because the entire system probably hasn't had anything done to it in 30 years. Rebuilt it all. MAste cylinder, brake calipers, new brake lines, new pads, new rear shoes (they delaminate with age (often locking up the rear wheel at a really bad time), and it's clear that the brakes on that bike have not been maintained).

My best advice is to strat by reading the links in my signature, particularly the first one.
Let her sit (no riding) until you've done everything needed to make her safe and reliable.

 

$450 is a steal, It even comes with the rare Maxim side cover option. All mockery aside, I am super jealous you found a 550 Seca for less than $1/cc, that is my dream.
Seriously, Moe speaks the truth about safety maintenance on these old bikes, don't become a dirty spot on the road because the brakes failed.
Why did the PO graciously ride it over to you? Because he probably blasted it full of ether to get it to run long enough to warm up and overcome a clogged enricher circuit. Once it's cold and won't start, well that's not his problem.

Good luck!

 

Yea I don't get the Maxim side covers either. As for the not starting problem I'm not really to worried about it, I'm sure I'll get it running well after messing with it a bit. And if you guys want to throw in some ideas of what I should do, I'm all ears. I'm gona start with checking valve clearances and go from there.

I definitely will take care of the front brakes, and I guess I will change the rear shoes also and anything else in there that looks like it needs to be changed. The possibility of delaminating shoes sounds pretty scary so better be safe than sorry.

Then I will be moving on to suspension. If any of you guys have any suggestions on how to get the bike to handle as best as possible without swapping forks and swing arms, please share.

 

By the way I forgot to ask, is there an alternative to buying the yics shut off tool for $50? That's $50 I could put into other parts. Is there a secret way of doing it that Yamaha doesn't want you to know about? Lol

 

You guys think this will work?

 

Yics tool is only used to really fine tune your engine. 5.3 out of 9 dentists agree that it's not needed at all. Save this item for last on your list of things to buy.

 

Yes there is. Don't buy one. It's not needed to get the carbs synched. The Yamaha procedure (in my guesstimate) is only necessary when you need the machine to pass an emissions test. Motorcycles are exempt from emissions tests in all 50 U.S. States.
Most of the old-timers (am I one now?) don't use it.

If you really want to use one:
The DYI version will work (it used to be all that was available), but you have to be very careful with the type of hose used, and to not keep it in the YICS manifold too long, or it will melt in place.

 

Thank you guys for the info, that's great news, now I can throw that $50 at parts!

 

if you need to an xs550 side cover can be modified to fir the seca 550 and will look better than the maxim cover. see the video in this link
'81 Seca 550 Right (Battery) Side Panel

you need a chain guard too seca are plastic but a maxim may fit on it it would be chrome to go with the chrome fender which came on the 81 seca only

 

Hey guys, so I'm trying to order parts, specifically stainless lines, and I'm wondering since my bike has clubman bars do I need to get a custom size? The bars are currently put on upside down so they look more upright but I do plan to turn them around. Anyone has any advice? Also suggestions for where to get the lines?

 

I am actually planning on removing the panels completely and also go with a smaller seat.

 

I believe Chacal can order custom length lines.

 

No it won't, the outer seal (against the opening in the chamber that the tool is inserted into) is missing.....mucho biggo vacuum leak.

No it's not. Yics tool is used to ISOLATE each carb/cylinder combo from each other while synching the engine. By definition, you cannot SYNCH the engine (having each cylinder produce the SAME ---not the maximum! --- amount of power as all others) while each cylinder is drawing a bit of power (fuel mixture) from its neighbors. That totally defeats the purpose/reason/logic of "synch".


An Insight From One Who Knows:

To review:

According to Yamaha, the function of YICS is to promote more complete combustion at low to mid-range rpm by swirling the mixture around the combustion chamber. They never made any direct power claims -- the system was promoted as increasing mileage up to 10 percent and promoting lower emissions through a cleaner burning charge. The increase in mileage was not through leaning out the mixture -- the increase in mileage and reduction in emissions was because less throttle was required to maintain cruising speed. They could use the same cam timing, jetting, etc. (for performance) and still meet EPA regulations. Yamaha stated that the greatest effect was while cruising at 50 to 60 mph.

The swirling accomplishes two tasks: first, it assists mechanically in atomization of the fuel and second it speeds and distributes the flame front (and therefore combustion pressure wave) more evenly throughout the cylinder. The later "Genesis" (water-cooled "X" engines) design accomplished this even more effectively through the 5-valve design, which accomplishes the same task through a wider rpm range.


To blank or not to blank (during engine synch), that is the question. Ok, what is the function of synchronizing? Manufacturing tolerances and wear. Multiple carbs offer the advantage of increased power and performance over the single carb configuration for reasons beyond the scope of this discussion. But at a cost.....

As each carb is dealing with a fraction of the total air and fuel flow requirement, each carb must meter things in fractions of the total. That makes for some very tiny tolerances. In effect, we have 4 separate engines -- if one is fighting the others, then we are wasting power and fuel and are worse off than we would be with a single-carb setup! So it is crucial that each one be perfectly adjusted and that all 4 then be synchronized to work in perfect harmony.

So, how can we reliably adjust an individual carb based on the results of the adjustments, if it's companions are contributing to the results? Now, to be fair-----if the bike has been reasonably well maintained and the cylinders are all fairly close to begin with, you can usually get away without blanking the YICS passage and still achieve a reasonable state of tune. At the opposite end of the maintenance spectrum, the YICS passages are often already plugged up with years worth of accumulated grunge and grime, so the bike is effectively being tuned with the YICS system disabled and the presence of the tool is irrelevant. But we have seen some examples of carbs where one cylinder was effectively relying on it's neighbors to supply most of the mixture through the YICS system, and this most certainly affects performance, especially the top end.

So, my recommendation: for an engine with approximately equal compression across the cylinders and valve clearances in spec, make sure the YICS passages are clean and use the blanking tool to tune the carbs.

 

chacal sells one piece crimped lines and has been known to work with members to ensure correct length start a conversation with him about it .
the lower line will be a stock size .

 

Like I said... Not the best investment if he's starting a project and he has a limited budget. I didn't say he doesn't need it, I said save it for later.

 

Nevermind, I got it. Below is the answer if anyone else is curious:

Hi again, can someone provide the following information?
Master Cylinder diameter - 1/2"
Caliper diameter - 38 mm

 

I have been a little busy and have been waiting for parts to come in so I have not done anything yet to the bike. Parts are slowly starting to come in though.

I wanted to talk a little about syncing the carbs. After doing a little digging around and researching how the yics system works, it is clear to me that you have to use the yics tool to sync the carbs. A few people argue that you should sync the carbs without the tool based on the fact that during normal operation the yics passages are open so you should sync the carbs with them open. However, that is not the case. Syncing with the passages open, all that will do is it will trick you to think that the cylinders are truly synced, however they are not (potentially) because if one is off, the other cylinders will try to make up for its slack, and give you a false positive. To properly sync, the tool is in fact required.

That being said, I do not want to pay $50 for the yics tool. I will make my own tool similar to the drawing in the above posts, and I will take into consideration what Chacal said and modify the design to make it work. Once I get it done and make sure that it works I will create another thread in which I will offer this tool as a communal tool for anyone in this forum to use. Whoever wants to use it can just pay for shipping, and hold on to the tool until the next person needs to use it, at which point that person will pay for shipping. Let me know if you guys think this is a good idea and I will make it happen.

 

Though I don't feel that the tool is necessary, it is cool to have one for all those that would like to use it. Good idea!

 

you will just have a dust collector. You are likely the only one in this forum who thinks the tool is needed.

consider the fact that many of our forum members use home made sync tools, the accuracy of the home made tool is less than the real tool.
and in the end close syncing is good enough for many of the members here.
few own the sync tools let alone color tunes.

also consider what happened to a member recently when he removed the bolts he broke off the chamber ends.
Help - YICS Plug Threads Broke
thats enough to convince me it is not needed
other members have used an oil sock to block the passages.

also leaving the tool with whom ever used it last will just result in a lost tool as many members drift away never to be seen again.

if you think the tool is absolute needed I am sure you could get a good price on one in this forum as many of those who purchased them us them as paper weights, much like the shim removal tool.

but thanks for the offer