Bike won't start cold - starts and runs when warmed up

Hello everyone, first post, I just bought a XJ750 Seca 198x (dunno for sure, think it's an 83, could be 80 to 84 though), for the grand total of...$60. I'm in Calgary, Alberta, and this is my first post, and first bike.

You can already guess she needs some TLC, one of the turn indicator's amber lens is broken, another indicator appears to be hanging off by electrical tape, the clutch cable is seized (I hope not the clutch itself), the clutch handle is broken, a mirror is missing, one of the side panels has all of it's clips broken and is only hanging on, the speedometer doesn't work, it's dinged, scratched and has rust spots.

That said, the bike is in pretty good shape otherwise, the motor, once it starts, seems to run fine, brakes seem good, seat is brand new, not bad for less than a c-note, brand new tires on it.

The bike also came with 2 other sets of carbs and a Haynes manual. Reading the manual, I'm thinking the shop he brought it to has probably never seen a YICS tool in their life (to be honest, neither have I, could be fun making one), so that could be one issue. The carbs are supposed to be brand new, but are brand new carbs even manufactured for a bike this old? If they grabbed them off another bike in the junkyard, maybe some ports are clogged with varnished gas by now? I don't know.

I'm thinking it might also be the valves, if the valve shims are out of spec, could that keep the bike from starting cold, with expansion of the metal bringing things close enough to spec once it warms up that it seems to run fine warm?

Anyways, thanks for any suggestions. Sadly, I probably won't be able to work on it immediatly, but any idea's on what to start with when I do get the chance would be greatly appreciated.

As for the clutch cable, easier to try to free it, or just replace the cable? Any way to easily check if it's the clutch itself as well?

 

Take the cable off and try to pull the lever on the trans with a screw driver if it moves it should be good. And you can soak the cable in some wd40 it worked pretty good for me but then again they are pretty cheap on ebay. As for the carbs it wouldn't hurt to clean them its pretty easy after a few times taking them a part.

 

A weak battery can turn the motor over if it's cold out but not have enough juice to fire up. If you have that situation, put a charger/boost on the battery for a bit and see if you get a start now. Time for a new battery.

If you find that doesn't change anything, just how warm does it need to be before it will start and run? That could be a choke/carb issue-plugged/clogged jets, etc.....

Don't worry, there'se enough people here that we will be able to help you get things going. It may take awhile, but we'll get you there.

dave fox

 

I don't think it's the battery, he had it on charge when I bought the bike, and mentioned that this was an on-going issue. Actually, I can't even turn the bike over right now; the owner is out of town, he was keeping it in his dad's garage (who happens to be our neighbor), his dad wanted it out, and he had no place to keep it, hence the awesome price, in any case, I bought it over the phone, and left the cash with the father while I wheeled the bike into my back yard, unfortunately, the previous owner still has the bike's key, and all the paperwork. I hope he didn't sell me a $60 bike that requires a $500 key


In any case, it couldn't hurt to at least try the battery though, so I'll do so when I actually get the key and registration.


As for the clutch cable, I took the cable off the trans lever and moved it with an adjustable crescent wrench, it moves and feels smooth and steady, no hang ups or roughness, but it did seem to require a lot of effort. But then, could just be me, I've really nothing to compare it against. I've been squirting penetrating fluid and lubricant down the cable, and it seems like it's loosened a bit, but I'll wait to tomorrow, after giving everything time to move down the cable, to see how it improves.

 

NO NO NO. WD40 is NOT a good cable lube for motorcycles, it gums up very quickly when exposed to heat. I learned this years ago the hard way when it caused a stuck throttle on my Norton.

Use a good quality industrial spray lube, like CRC or Tri-Flow.

Use WD40 to drive water out of things. WD=Water Displacement, why it was originally invented.

 

+1 on bigfitz' no no's.
If you can't afford the cable lube then reg 30w motor oil will do.
Sounds like you may have gotten a pretty good deal- all
you need to do to get it right is take your time and research this site.
Most of whats ahead has already been covered somewhere here.
These bikes can be brought back from a very near dead place to once
again scream down the road.
Two things must occure for this to happen:
1, NO SHORT CUTS!.
2, get a manual

 

Don't worry, I'm not using WD-40, I've got this penetrating fluid called P2000 and an lubricant from the same company. Supposed to be good stuff.

EDIT: Just got back from shopping for the bike, ordered a new clutch handle and bought a replacement rear-view mirror. Talked to some guys too, went to a Honda dealership (closest bike shop to my house), they said they would work on other makes, but the shop rate is $110/h (ouch!). They never heard of a YICS tool, but you can't really blame Honda guys for not knowing that. Went to a bike dealership that sells and services Yamaha's next, they never heard of a YICS tool either, slightly less forgivable since they do sell Yamaha's.

Then I went to a bike junkyard dealership next, suprisingly, these guys had seen a YICS tool, they had 2 of them, and they happened to be the place the previous owner fruitlessly brought the bike. They couldn't fix it, despite being familiar with the bike, so it certainly doesn't bode well with me.

I told them the problem, they suggested rigging the starter circuit up through a relay such that none of the voltage going to the coils is lost through a switch, and then finding a 3/8ths steel rod, cutting it to the length of the YICS passage, and cementing it in place. They absolutely hate the YICS system and recommended permanently disabling it. I'd rather not, but if push comes to shove, has anyone else ever tried it?

That said, looking through szabon's topic on his weird problem, I found this. Since the first sentence describes my bikes issue perfectly (though I haven't tried starter fluid yet), this is definitely something I'm going to be looking into.

Haven't started looking for a real shop manual yet, still have the Haynes manual though.

Second EDIT: Found the helpful topic on VIN's, discovered it's actually a 1982.

 

Sorry for the double post, but I've just got the keys and paperwork done. The bike is officially mine now. I've been reading some of the how-to's and following some topics around here, so I think I've got an idea of what to do, but I'd like a double check from you guys first, because I've never done this before and really don't want to ruin the bike.

Sounds like I should remove the carbs and clean them according to The Church of Clean, RickCoMatic's Old-School Method, and with special attention to Gamuru's How to Clean the Enrinchment Circuit Well, because the symptoms he describes perfectly match my bike.

Some time between this and putting the carbs back on the bike, I should check between the cam and the valve shims for proper clearance, correct? And replace them as needed.

I've heard some people recommend against using magnets to remove them, to prevent metal particles from being attracted and increasing wear, but the head is aluminium isn't it, and if I'm removing them, it should only be because they are out of spec and won't be going in the bike anymore anyways, so there shouldn't be any risk of magnetizing the new shims in the process, long as I don't put the old shims next to the new ones, so I don't see an issue myself, but opinions are welcome.

Back to the carbs, once I clean them enough to operate off them, and replace any worn parts, I need to put them back together. I have the Haynes manual, I recall though that someone mentioned an error in it that I must watch out for.

After getting them back together, I need to bench sync them, according to Gamuru's How To: Bench Sync Your Carbs, though RickCoMatic suggested to use a strip of business card instead of paperclips. Thoughts here?

Then I need to install them back on the bike (Haynes manual again), and while I'm at it, should fit an inline fuel filter into the fuel line. Hopefully, with the bench syncing and cleaning, the bike should fire. Then I need to sync them with a home-made YICS tool (which includes a rubber washer missing from the plans online and uses high-temp silicone hose) and a home-made manometer, which doesn't sound too hard once the tools are built.

After that I buy a colourtune plug and adjust the mixture screw to just barely blue right, I should set it rich and yellow and then back it down to blue, since these bikes prefer a little rich rather than lean. (this is the screw that Haynes says in big angry letters "Do Not Adjust", correct?)

After that it's test rides and "plug chops", which is from my understanding, cutting the engine while at medium and high RPM's to see the colour of the spark plug and adjust the respective screws to create a nice, golden brown insulator. I'm a little lost as to which screws adjust, and what RPM I should perform the chops at (doing them all in 1st should be alright too, or should I be doing them in higher gears to load the engine more?) but hopefully I'll figure it out by then.

After all that, it's on to other issues, brakes, ignition, paint, TCI box.

Anyways, am I missing anything? Any important details I should know, anything out of order?