First time XJ Owner

Hey all. I'm new to the XJ world, and I want to start off by saying that this is a great site.

I have tried to look around to see if this has been posted before, and I posted a little bit in another thread, but I figure I shouldn't hijack that post so Ill try and lay it out here.

I bought an 1983 XJ550 from a guy who said that it needed carb work. The carbs were off when I bought it so I put them back on there. The previous owner told me that the tank was clean, but I drained the gas anyway and it looked ok, and I don't see any rust in the tank. So filled it up and gave it a jump and it started. It would idle ok, but as soon as it got and throttle, it would die out.

So I took apart the carbs, put in new float valves, and I determined that the Air jet screw (for a lack of a better term) was clogged in 3 of the 4 carbs. After a lot of work and carb cleaner I can see daylight through all of them. So I put it back together and it idles at 1400 or so.Now it will throttle up, but sometimes it won't throttle down. When it does this the engine stays up at 3 to 4k. It seems pretty intermitant when this happens.

The cable has good action, and isn't getting stuck, and the choke as far as can tell is staying shut as well. In order to get it settled down I have to shut off the bike, and start it again. I would try and sync the carbs, but I don't have the tool necessary to do it, but I'm not so sure that will fix it.

If anyone has any ideas, I would be very appreciative. And please point out the little easy things, I won't take any offence, this is my first project bike and I am by no means a master mechanic.

Again thanks for the help.

-Kevin

 

Need to know a little about how you used the carb cleaner. Describe the air jet screws. These usually don't clog so I suspect you are refering to the pilot jets and main jets which are brass. Air leaks can cause the high idle but a miss-tuned and miss-synced condition can cause this also. If you soaked the carb bodies in carb cleaner for an extended period then you could have damaged some rubber orings and they are allowing air to get in. If you used a spray cleaner then no worries. It could also be a low fuel height level in the carb bowls. Let us know some more and welcome to the forum.

 

I used spray cleaner on the jets after I took them out. I don't believe I abused any seals, but I could be mistaken. I'm 99% sure they are air jets. Below is a crude drawing of what was clogged its the one (-) that the arrow is pointing to.

I guess I need the tools to sync up my carbs. One thing that is really starting to bug me is my floats keep getting stuck when I put the carbs on and off. I put new float valves in there so im not sure whats going on.

 

I am more familiar with Hitachi carbs but the Mikuni's are similar. Your diagram is pointing where the idle jet should be but I need someone who knows Mikuni's to chime here on that.
However your problem with the floats is not unusual and could be your problem altogether. What you need to do is pull out the float and it's pin then if you have a dremel tool insert the pin in the dremel. At a fairly low speed turn the pin inside the float where it fits using some Mother's rubbing compound or even car wax. This will polish the pin seat and stop the floats from dragging.
Since you used spray cleaner don't worry about the orings. It is only an extended dip in carb cleaner that will hurt them. After polishing the float seats and pins I think all you may need is a colortune and carb sync. This is best done at a carb clinic. I you are near Dallas Texas there will one there in a few weeks. Rex and I would be glad to help you tune the bike up.

 

check for air leaks

specially in the carb boots!

and check the choke mechanism.

mine used to do it a lot

now it rarely does it if at all,

meaning i cant remeber the last time it did it

 

Secaman mentions something that I was thinking of last night. When you pulled and reinstalled the carbs some cracks may have opened on the intake boots. These are the black rubber ones that mount to the engine. I didn't suspect this at first because there was no high idle before removing the carbs. Usually if these leak the idle will remain high and not come back down, whereas a leak from a fuel passage oring may be intermittent.

 

Thirdedition, like yourself I am far from being a master mechanic and am working on my first project bike, so take my $.02 with a grain of salt. The jet that you're indicating in your diagram is the pilot jet, which meters fuel at low rpms (something like idle to 1/4 throttle). On mine, the carb boots were in rough shape and didn't get any better with putting the carbs off and on. As BlueMaxim and Secaman, have indicated, a leak in your intake boots could explain your problem, so an exam and a coating of rtv silicone certainly couldn't hurt and could solve your problem. Also, if your floats are sticking and your jets were clogged, what kind of shape is the rest of the carb in? Are your main jet needles sliding smoothly? A little bit of varnish on that cylinder might make it stick intermitently.

 

Well I'm thinking that im going to break down the carbs one by one and give them a through going through to eliminate any build up or clogging. I'm going to try and find some new clamps for the carb boots to see if that helps me at all. The main jet needles seem to be moving smooth, but they may have some build up on there. Although I can see them when the bike is reved up, and they aren't sticking from what I can tell.

On an unrelated note, my font brake caliper is sticking. Any suggestions on getting a rebuild kit for it?

 

Small world - same problem here. This thread: http://xjbikes.com/Forums/viewtopic/t=671/ suggests a cleaning/greasing might do the trick. I know from past experience that sometimes if the bike falls over, the caliper(s) will hang, but this can be 'fixed' with a few raps from a screwdriver or mallet.

This works somewhat for me now, but as soon as I reapply the brakes, they/one will clamp up again. So I'm looking to clean and/or rebuild as well.

Tips are appreciated - I just found this out on my way out of the garage this morning, so I haven't been able to look for solutions in my Haynes manual yet.

And to get back on the carb topic - I'm having similar issues as well. I've got her running moderately now, but she's still slow to warm up and coughs every once in a while. Interestingly, on Sunday cylenders 3 and 4 were the last to kick in and start running. Yesterday it was 1 and 3. Tempermental. I'm picking up new plugs today, got some Seafoam this morning and we'll see what happens. BTW, I did a pretty good check of my boots when I had the carbs off, so I'm hoping the Seafoam, plugs, and perhaps taking a crack at resynching will get her going smoother. She HAS come a long way from being completely dead, though, so there is hope.

 

I sent you a carb cleaning guide via PM. This will give you something to read tonight!

 

Awesome, this will help a lot. I put in an order for a manual as well. And once the new CD comes out I'll pick that up too. Thanks for all of the help so far.

 

The new XJCD version 4.0.2 is READY! Yes, and available now through Brad Bowen. I highly suggest you have this for the carb clean. The cd excels in this area. D.V's text along with photos is something not to be without.

 

if u clean your carbs

dont take them off the rack!!

just makin sure since u said u were gonna clean 1 by 1.

 

For just cleaning them, I agree with you Secaman, do not remove the carbs from the rack. It is an unnecessary risk. Simply pull each carb apart in turn and you won't run the risk of mixing parts up. You will also have a complete example intact should you mix up jets on one of them (actually two more come to think about it). Slow and steady is the word of the day on cleaning these things. Just DON'T stick anything like a drill bit into any of the ports or orifices! The only thing safe enough to do this is a nylon bristle or copper wire (piece of phone line works nicely). Good luck and be careful!

 

Good pints guys, but they are all in the carb cleaning guide.

 

I have my carbs off at the moment, the idea was to strip them down and give them a good clean then checking and adjusting the levels before putting them back on the bike. Well, their nice and clean with jets all blown out. Think I'll have to pass on the balancing though because some previous owner didn't know how to use a screw driver and has made such a mess of the drain plugs I can't get them out.

Faighaigh.

 

Well I have the bike back on the road. I still need to sync the carbs, but I ran some seafoam through the tank and carbs as well as adjusting the floats, and it no longer revs up like it was doing. I'm going to sync up the carbs here soon but I dont have the yics tool. I was really wondering if I really need this.

Also I lubed up the front caliper I'm waiting on the rebuild kit to come in, but it seems to be working ok for now. Hopefully once I get it all the way apart and rebuilt it will be good as new.

Ill try to keep you posted on my progress.

-Kevin

 

I know how to use a screwdrive and I still made a mess of two of my drain screws - I'm starting to think someone had put some lock-tite on the threads for some reason. I eventually did get them out and cleaned up and am passively looking for 2 replacements. Those darn screws cost about $12 each new!

That said, you don't need to take out the drain plugs to do a carb balance. Perhaps you meant checking the float levels?

 

Hey fellows, Nick pointed out a reasonably priced solution for your drain bowl screws. I hope Sno will sticky this some time soon, we keep running into this issue. Here goes:

http://www.mesanet.netfirms.com/CarbDrainScrews.htm
Here's a link to a guy who makes new ones with hex heads.
Steve C (stevec5000@yahoo.com or stevec5000 @ gmail.com) is your guy for float-bowl drain screws. I think they were $10.00
His work is here: www.mesanet.netfirms.com/CarbDrainScrews.htm

There you go gents, I'm ordering the stainless myself. Good luck and may the force be with you.

 

Um, they LOOK cool, but I don't see any contact or ordering info, even going up a page or two. Am I not getting the whole page, or what?

 

Well, after doing well on Saturday. Sunday the 4th carbs floats strated to act up again. So I took the bank of carbs off again and adjusted the 4th float. Now its back to staying reved up again. I'm really struggling with what to do. The 4th carb is really starting to get on my nerves. The other 3 seem to fine. Ill keep trying to adjusting it and clean it up some more. If anyone else has any ideas I'm all ears.

-Kevin

 

Steve C (stevec5000@yahoo.com or stevec5000 @ gmail.com) is your guy for float-bowl drain screws. I think they were $10.00
His work is here: www.mesanet.netfirms.c...Screws.htm

I'm kinda wondering how you missed it Oblivion. You get enough sleep last night? Just kidding bro, I miss one now and again too. Hope this helps.

 

Yeah, duh. I just saw the link in the different color - totally missed tha e-mail address. And yeah, I slept like the rocks I was breaking yesterday, so I can't use that excuse. Just a plain old ID-10T Error.

And holy crud, before I even remembered to finish out this post, I got a response from him and have the stainless allen screws on order. Sweet. Thanks, Robert.

 

I've been lazy, I promised to buy some a few weeks ago and have been ignoring the little voice inside my head (you know the one that tells me to whack idiots on the head), wonder if that will come back to haunt me? Glad to hear it, I'll get some soon, I promise!

 

Thanks for the tip re Drain Plugs Robert, bit late for me though as I ordered new ones from Motogrid last week. Mind you the tracking advice shows they are on their way to Clover NC so I may have to order some from your bloke.

Found that one of the floats was a bit twisted making one side higher than the other, have tried to level them and adjust the heights. Almost ready to give the bike a try and see if she is happier now. Last time I stripped a carb down was 1965 it was an Amal TT of my Velocette Viper Clubmans and a bloody sight different to the bank of 4 Hitachi's on the xj.

Faighaigh.

 

This begs the question as to why your floats would be out of whack with twisted floats? I'll bet PO didn' t have a clue and just grabbed and bent what ever fell easily to hand. Glad you found it. These little carbs are sooooo much easier that those damnable Zenith/Stromburgs or SU's. I hated them with a passion. These are very reliable with minimum service required.

 

Once you get those float levels set them a colortune and sync is the only thing that will cure that revving. Providing of course that there are no air leaks. Keep us posted. Where ever you are I would look for a carb clinic where you can get the colortune and sync.

 

Thanks for the advice blue maxim but I doubt there'll be a carb clinic within a thousand miles of here, in fact I probably have the only xj700 in Spain. Not sure what a colourtune is?

Put the bike back together again yesterday and got zilch. No juice getting to the carbs at all but juice flowed from a can bypassing the petcock. Stripped down the petcock but found nothing wrong that I could see so I put it all back together again and she fired up first hit. I think there's a problem with the throttle linkage because at first it was just slack, there was no pressure at all almost as if it wasn't connected then there was a click and it worked fine. Certainly need new cables for throttle and choke.

Went out for a short run and she seemed ok, will slip out later today for a longer ride.

Faighaigh

 

Hi Guys,
I'm also new to the XJ scene and to this site. Thanks so much for putting the effort in, your doing a great job. My son recently bought a '84 XJ750 Seca with only 26k on it. It seems to be a bit of a rare bike, at least according to the local dealer. I'm having carb problems too... Go figure! The bike sat outside for a couple of years as near as I can tell. We cleaned and resealed the fuel tank with an epoxy, removed the carbs & used spray carb cleaner and compressed air to clean them, set the floats and reassembled them. The bike started and ran fine, but seemed to hunt slightly at idle. I thought we should do it right so I suggested we take the bike to our local Yamaha dealer to have the valves adjusted and the carbs properly balanced. Since we got it back it runs extreemly rich on three cyls, and just great on one. I pulled them apart again to find that everything looks good inside to me. In frustration I brought it back to the dealer again and he pulled everything apart & said he's stumpped because it all looks good to him. After more money than I care to talk about we still have a very rich running bike and my son thinks his dad can't fix anything. (I've been an automotive mechanic for over 20 years) What's this CD I see your're talking about? It sounds like it might have some good advice on it. Where can one get a copy? Thanks for letting me vent a bit...

Doug

 

Hey Daddio (I've always wanted to say that),

I don't have specific advice other than the XJCD thread is here: http://xjbikes.com/Forums/viewtopic/t=148.html which in turn will lead you to the CD's web page which is here: http://members.tripod.com/dave_jack/id47.htm#xjcd

I hope that helps. I thing there are some delays in geetting them out right now due to some last minute revision on the new edition, but they should get you hooked up.

You said they did a valve adjustment and carb balance, did they actually adjust the mixture? How (using a colortune, CO sensor, etc.)? Also, how are you determining that 3 cyls are running rich - by pulling the spark plugs? Just curious. I'm just trying to ask questions that might get others to help you. With 20 years as a mechanic, you're already well over my head.

Oh, one other question would be if the shop you took it to used the YICS tool when doing the adjustments. I've read differing points of view on how important that is so I'd be curious if it was the problem in your case.

Good luck, Daddio!

 

Thanks Oblivion,

I'll order that CD for sure as soon as its available. I pulled the spark plugs and found that #1, #2, & #4 were all black & sooty and #3 was nice light brown. I'm not sure how the shop did the carb balance especially since the bike ran so poorly after it was done. I'm thinking the choke valves may not be seating properly (I hope that's all it is anyway). I'll pull them off again this week and give that a try. After that I'm all out of answers... I'll call the shop & see if I can talk to the tech again and I'll ask him about how he balanced the carbs the first time. Thanks again for the help.

Doug

 

Hey Daddio, just got my XJCD v4.0.2 in todays mail, so it's shipping!

 

Robert or Oblivion.

I ordered drain screws several weeks ago now and as yet they have not arrived, apparently UPS thought Spain was in either N or S Carolina IL IN or Kentucky and tried to deliver to addresses in all those states.

I've been trying to order drain screws from the fella suggested but my e-mails just keep coming back undelivered. Is the bloke still in business, does anyone have a current address?

Faighaigh.

 

My last contact with Steve was April 26th via the gmail address Robert mentioned: stevec5000@

The rest is gmail.com but I don't want to make it too easy on spam harvesters. If that doesn't work, I don't know what to suggest. Too bad about the UPS SNAFU.

As for the XJCD, I dropped a check in the mail a month ago and it still hasn't been cashed (though Brad said he got it), so I'm not expecting to see the CD anytime soon. A little disappointing since the reason I was getting the CD was to clean my carbs and they've already been off and back on the bike.

 

I ordered the screws about the same time you did, Faighaigh, and mine came right away. Must be the old postal service again...

 

The screws arrived yesterday shortly after I had that moan, they had been returned to the supplier who forwarded them on again by US post.
The petcock kit also arrived yesterday and I was hoping to play with the bike for a while today, but my son is coming to visit for two weeks on Thursday with four of the grandkids. So I can't see me getting much more done than hopefully draining the carbs and getting the tank off.

I'll try that address for the screws again, think it may be an issue with my address. I'll try again using the hotmail one.

Thanks fellas.

Faighaigh.

 

any chance those drain plugs fit the mikunis?

 

Finally got them on 5/25.

 

P----d off good and proper, wife is wearing her smug told you so smurk and the cat (her familiar) won't come near enough to recieve a blessing from my boot.

Managed to get just one of the drain plugs out today and found why they are so hard to move, the bloody things are rusted in! Decided to leave well alone.

The new stainless steel one's I ordered are ;ook really good but they are about 0.5 inches to long, they others I bought that took so long to get here are far to small, wrong size altogether. Not very pleased with the firm I got those from, ordered 4 drain plugs and got 3 ordered 3
screws for the diaphragm covers and got 4.

But so far the petcock repair kit I fitted seems to be working.

Faighaigh.

 

Faighaigh, the screws were longer than my originals, too, but they do the job of keeping hte gas in the bowls if you can stand seeing the few extra threads.

 

Thanks Oblivion.

We have a house full of grandkids here right now but when they go back to the UK I'll try again.

Faighaigh.

 

Bit of an update on the petcock issue.

Took the bike out today for the promised test ride and the original problem is still there ie: downhill fine uphill no juice to the carbs. Also noticed the tap was very hard to move from one position to another. Stripped the petcock down and realised that most of the components of the kit I bought just don't fit. I should have seen that when I fitted them but things were a bit hectic at the time.

Not having a lot of luck with parts bought on ebay laterly.

Faighaigh.