New Person.. aka, me.

Hi Guys,

I'm Steo. I'm, like, totally new to motorbikes. I wanted to save some money on the car, so I did Q-ride and got my motorbike license and then bought a Yamaha XJ650 because it was the cheapest bike I could find.

I love it. I'd love to be able to just take it down the coast or for a long ride inland for the sheer riding, not really to get anywhere.. however, I need to rectify a couple of things first.

Fuel consumption... is terrible. Actually, it's worse than my car... there, I said it. My 650cc bike chews through about 12.5L/100km. So my excuse for getting a bike to save fuel is comlpletely defunct. That said, I noticed a few guys seem to get a lot better fuel consumption out of their bikes, so I wanted to know how I can increase this? Granted it's an old bike and it's only ever going to get so much fuel consumption - but I feel like I should get a little better out of it. Previous owner said it gets around 15km/l - I'm getting about 8 or 9.
I'd like to fix it up a bit and learn how to work on it, but going off of what I've read on here - everyone is saying I need to clean the carbs. At risk of sounding like a complete idiot - is there a complete idiot's guid to this thing? I read the guide (both of them), but I couldn't get the hang of what they were talking about - like, what is a manifold? And what are these 'cap-screws' that if I break them, I break the bike forever?

Anyway, I know that people are busy and stuff, but would anyone be able to help me out by suggesting a few things I could do to the bike, and maybe also point me to a place with a picture by picture process of how to clean the carbs? Or at least a picture that says what is what, so I can know what things are and what to avoid?

After all that, hope to get to know some people and I'd say I'll be around regularly finding stuff and asking questions.

Cheers!

 

First off get a manual, that will explain a lot. Then get ready to read, here's a good link: http://xjbikes.com/Forums/viewtopic/t=1 ... clunk.html
Read Carb cleaning and clunk test, they are not 5 minute fixes, but they will improve the performance of your bike.
Oh, and welcome to the Forum!

 

Thanks!
The bike came with two manuals, and I downloaded the owners manual online.
I've read the owner's manual literally from front to back, but by the sounds of it - I should do the same with the other two...

I'll try and work a little more out on my own, I guess, but most of it is pretty much like trying to read a different language - you may know one or two words here and there, but the rest doesn't make sense until it's explained.
Main problem is I don't have a garage or anything to work in, so what I do has to be able to be done and finished in one day-light session on a Saturday - which means if I'm trying to read and work.. I'm not sure I'd make it lol..
I'll be back when I've read more

 

Congrats on joining the riding fraternity and your new-to-u bike! I converted your metric figures and it worked out to be 18.82 mile per gallon, which is horrible. The guys here can tell you what you should be getting.

Unless a previous owner has misplaced the cams, the problem is probably in the timing and/or the enrichening circuit IF the air filter is clean, check that first! I understand that you have to be able to start and then complete any work that you do since you need your bike for work but checking the timing and then changing it is pretty simple and you can start on the carbs by checking to be sure that the enrichening (choke) bar is returing completely and that each plunger is fully seated. You can loosen the set-screws to return each of the plungers then reset the bar.

jeff

 

Cheers,
I'll definitely check them out.. I've copied your post and emailed it to myself at work - I'll take my manual with me and try and work out exactly what you've told me, but I'll do it once I know!
I think the air filter is clean, but I don't have an air compressor so the best I could do is have a look and give it a shake - looks almost new, though, to be honest. PO said he did most of the easy stuff 2 years ago when he got it from a mate - apparently before him, it'd been sitting in a shed for years. And I'd bet any money he's never taken the carburettors off. He tweaked with them to make it sound better, but that's all he did.
Got a feeling this'll be a big weekend...

 

Here's some additional things to check for mileage -

Float levels (all 4) using the "clear tube method".
Proper jet sizes (carb removal)
"choke" cable hanging up a bit, must be a little slack
running sync
Proper "pilot" screw adjustment (all 4) proper plug colour - "plug chops"
brake drag (see if the front tire spins freely)

run a search here on the words or phrases you aren't familiar with.
Have a look at your rear brake shoes before you ride again !
Welcome to the site !!

 

WELCOME from TN and GOOD LUCK!!! Lots of info and HELP here...

skillet

 

welcome looks like everyone has you on the right track already

 

welcome m8!

 

Welcome Steo, glad to have ya

 

Hey Steo, I just got an XJ 550 Maxim a few days ago myself, so I guess we can take this newb journey together as we fix up our bikes! Welcome!

 

gday steo,im in brissy myself on the northside,near sandgate, there is an old german fella here who loves to work on these bikes, if you wanted to get him to do the valves and carbies real quick just for an initial service he would be the bloke to do it,his 1st name is EKKE,he is in the yellow pages and on the net,i get 18km/l on my bike and thaTS 90% city riding.

 

Thanks for the welcome, guys. Read and highlighted the carburettor manual today. Very, very confused and going to do a lot more reading. Might track down this german guy, though... any idea how much he would charge? I mean, I want to learn to do it myself, but that might have to wait until I have a garage of my own..
Fixed the cutting out problem, new fuse-box goes in tomorrow. Maybe even going to at least drain the carbs if I can find what the heck the bikey I was talking to today was talking about... New oil went black pretty quick - also having second thoughts about whether or not I put the oil filter in backwards or not
Looking forward to getting to know the bike a little better.. best way is with a little TLC I think!

 

This is a diagram of a 650 G model, only one I could find on line. It shows the sequence in which to oil filter mounts on the bike:

Tag Description Req Price
1 SKU: 4H7-13447-00-00
COVER, OIL ELEMENT 1 $45.78
2 SKU: 1L9-13441-11-00
ELEMENT, OIL CLEANER 1 $11.12
3 SKU: 90480-23193-00
GROMMET 2 $6.83
4 SKU: 93501-02018-00
BALL 1/2
5 SKU: 90501-12413-00
SPRING, COMPRESSION 1 $4.81
6 Loading... SKU: 91609-20018-00
PIN, SPRING 1 $2.99
7 SKU: 1L9-13340-01-00
BY-PASS VALVE ASSEMBLY 1 $44.56
8 SKU: 93210-16629-00
O-RING 1 $2.71
9 SKU: 93210-87723-00
O-RING 1 $7.46
10 SKU: 90201-21608-00
WASHER, PLATE 1 $2.71
11 SKU: 90501-20422-00
SPRING, COMPRESSION 1 $4.83
12 SKU: 4H7-13417-03-00
COVER, STRAINER (4H7-13417-02)
13 SKU: 4H7-13337-00-00
PLATE, BAFFLE LOWER (backordered) 1 $5.47
14 SKU: 98580-06010-00
SCREW, PAN HEAD (92503-06010-00 3 $1.65
15 SKU: 4BB-13414-00-00
GASKET, STRNR COVER 1 $8.56
16 Loading... SKU: 90340-14118-00
PLUG, STRAIGHT SCREW 1 $10.97
17 SKU: 214-11198-01-00
GASKET 1 $2.49
18 SKU: 90110-06138-00
BOLT, HEXAGON SOCKET HEAD 13 $2.20


Cheers, Graham

 

Well, I replaced the fuse box and that all went well. I tried to sync the carburettors and made a manometer.. 1 did not sync with 2 - unless I screwed until the revs were at about 4k... and couldn't be adjusted down via the idle screw... after I'd got to at least where 1 and 2 were stable, 2 synced with 3 ok and 3 synced with 4.

Bike sounds a lot different, and has heaps of power at low revs which before it would sputter and nearly die trying to go around a corner uphill... but I can' adjust the revs below 1500.
Yup, you heard right - the idle thingy bottoms out and feels like it's going to unscrew into my hand - and it's still sitting at 1500 revs. Anyone else had this problem?
Other than that, the improvement is just crazy. One of the screws (number one) was in nearly all the way, whereas the other three weren't anything like that.

Took the bike for a ride and it went great, better than when I bought it by WAY far, but I have a feeling I may have fixed the symptoms but not the disease...

 

Have you checked your throttle cable at both ends?
There is the easy one by the throttle itself and then there should be another down by the carbies. Check to see if there is free play and check that the cable is not hanging up anywhere. Like if you sit on the bike and turn the bars right to left, does that affect the rpm's. When you gas it, does the throttle snap back to the idle position? Check the the choke cable too, to see if it is doing the same as the above.
Other than that, the only thing that I can think of is there is air getting sucked in some where. Check that all the clamps are properly tightened and the boots are on fully.
Sounds like like you've almost got the bugger licked. Now you just have to sort out the Gremlins!

 

do you have play in your throttle cable that is possibly the problem holding the slides a bit open that's why its not hitting the thingy lol throttle stop is the proper name. But to sync them right it needs to be synced at idle it is possible 1 of the carbs is also a slight bit more open then the others holding it off the stop. Get the idle down and re sync them its possible you gave all the screws to far in holding it so the stop wont hit. Takes time when they are way out of wack. That's why most people bench sync them first when they are off. That's why it is making a knock noise when you take off. To do it right you need to check the valve adjustment first. But i know you have to do what you have to do

 

Another thing you should probably check. Your oil level. You may have a non functioning petcock (vacuum isn't working) and you're dumping gas into your crank through the carbs/pistons. Check to see if your oil smells like gas, and see if it's higher than it should be (sight glass).

That could be where your gas is going. IF you do have gas in your oil. DO NOT run the engine till you get it changed out with fresh oil.

 

Thanks, I'll check those things.

Something that completely escaped my mind until I read Maxim-X's post.. two of the rubber boots clamps were hanging off - they were never put back last time the bike was worked on... I'll go and put them on now. Forgot when I was doing the bike yesterday. Noticed it, but never fixed it.

And cutlass, yes, my #1 carburettor seems to be open more than the others - but if I try and turn it down - it starts sucking oil towards it really fast in the manometer.

Going to get in contact with this guy at Sandgate and see how much he'll do my bike for. At least for the first service, so I can know the bike's the way it should be. Atm, I don't know how the bike should be, so it's hard to try and attain that when I have no working knowledge of bikes to begin with...