1982 XJ650 Hard-Impossible Start - Seafoam & Carb Cleaner

Please note: this bike runs well once it starts, but seems to be a gas guzzler, getting only about 28 miles/gallon. Anyone know what's average?

Here's the trouble: When initially starting the bike it can take upwards of 10 minutes to start. If you block the air intake to the carbs (I put my hand over the number 1 intake) the engine jumps to life immediately. Since I put the carbs back on, this has become a process of removing the seat and jamming a rag into the air intake box to block the airflow until the engine turns over.

The bike runs a little rough for about a minute and then it's fine.

Other things: The idle is naturally high (at about 1800). The screw attached to the carbs that seems to adjust the richness up or down is screwed all the way out.

The above problems happen whether it is hot or cold, but cold seems to be worse.

Work that has been done: Carbs have been cleaned but possibly not so well as not a lot of time was taken. I will be taking them apart and working on them this weekend. I understand that it's possible the main jets have been done but not the idle jets.

Can anyone tell me what Seafoam is and whether it can damage the engine?

Is it safe to spray carb cleaner into the back of the carburettor (where the air intake is) while the bike is running?

Let me know if you can help.

 

From the sounds of things, your enrichment (erroniously referred to as a choke) circuit is haywire. Removal of the carbs and a complete deep clean is necessary (see Rick's How To for the skinny).
SeaFoam is a fuel additive that helps clean and keep clean internal combustion engines. It's use is recommended. An alternative would be Berrymann's B12 Chemtool (though I have not seen it in years). For cleaning the carb, empty out your tank and pour in a mix (50/50 if I remember right, check for this process in the archives) of fuel and SeaFoam. Allow it to get into the carb bowls and then start the bike briefly. This will pull the mixture into the vents and jets. The bike will smoke badly but that is ok. Turn off the bike and let it sit over-night. In the morning, refill the tank with the gas you drained off and fire it up. It will smoke badly as before but will soon clear out. This should get you a good cleaning but it does not replace the task of a proper cleaning.
Pull your carbs.
If you post your general location in your avatar, you might find a local member is close by, waiting to lend a hand.
Best of luck!
I am not "THE" carb guy, there are a few other members who are. I expect they will weigh in and set any errors I've written straight. Do hit the archives, you will find the information you need to perform a complete resurrection of your carbs.

 

Negative. Seafoam is a government experiment on motorcycle owners. Its made with
1 part Girl Scouts.
2 parts Road Gremlin Guts
and a small dillution of Grapefruit Juice

and BTW I agree with Robert that you have a Kinky carb issue

*EDIT* Clean your carbs SPOTLESS before you start any troubleshooting. When you invite me over to dinner, we will EAT off those carbs.

 

Re: 1982 XJ650 Hard-Impossible Start - Seafoam & Carb Cleane

What I learned today was this:
- My carbs were NOT clean. No duh?
- It takes me about 4 hours to clean one carb.
- It will take me the rest of the week to finish.
- It will be totally worth it.

I have some more details but I'll get to those tomorrow.

 

Nice. Take some pictures of your progress, thats what I have done. Ill be posting them later. I just finished the top end of my carbs today, and have only a little more to go on the bottom end. Pics to come soon.

 

I get about 50 mpg and thats driving it pretty hard. Always gunning it at the green light. I don't know I just like getting way ahead of the wolf pack and messing with the local fuzz when you DONT go over the speed limit.

 

Julie:

YOU are my kind of gal!

Be sure you read my Post called: Clunk Test

Don't put those Carbs together without the Diaphragm Pistons passing a Clunk Test!

You are going to get a "License To Tweak", Julie!

An Official "Double-Oh X-J'er"

Don't just Clean the Carbs ... Prepare them for Fine-Tuning.

You GO, Girl!

Rick -- (adding Julie to Carb Cleaners Merit Badge Club)

 

My 650 runs fine, but since I travel for work it can sit for long periods of time. I think it might be good to add a small amount of safe solvent in the gas to help reduce/prevent buildup of varnish, etc. while I'm riding.

But I'm aware some clean carb products can soften and damage rubber XJ carb parts. My Seafoam can says that in addition to being a "carb flush" it can also be used as a normal maintenance additive. (1 or 2 oz./gal.)

any advice from our carb gurus would be most appreciated.

thanks

 

Hey, thanks Rick! I'm not ascared 'o no carbs no more!

I worked from the time I got home yesterday (about 5:00) until about 10 in the bloody freezing cold. It was Clunk Test that got me started on the carb cleaning...I knew that my carbs did not do that. I expect I'll need another 4 hours on them, although #1 was nearly spotless to start with. 2 and 3 were moderately gunky, and 4's needle jet had to be knocked (very carefully) free it was varnished in so tightly.

I didn't take pictures as I was too busy cleaning, and the space I work isn't really large enough to have a camera sitting on the bench. (Soon to be remedied.) I might try this again with a spare set of carbs that I have. Has anybody run a step by step online clinic of this? I'm sure someone must have done. Webcasts of bike repairs would be brilliant.)

I haven't put the carbs back on yet, because I wasn't fully satisfied with how clean I got them. The needle jets are brass again instead of some flat dirty yellow colour. The jet needles are clear silver. I wasn't sure how to get in to clean the idle jets, or if it could be done. Here's what I did, tell me now if I f'd it. If I could not pull the jet out to look at it (as in the case of the idle jets, I think?) I sprayed carb cleaner in and blew it out with canned air.

The plungers passed the clunk test in warm air, but not so much in cold/moist air which is what I'll be driving in until summer. (West Coast of BC) I am prepared to go back in now with polishing equipment. I tried my Dremel but was not comfortable with it, so I went back to polishing by hand. It gets a bit boring. Any thoughts about the soundness of using a metal polish on brass parts and inside the carbs on the aluminum? I tried it a bit and it seemed to get it REALLY clean but I was worried about residue.

 

On the carbs that people send to me ... I use my Dremel with a ScotchBrite Pad to remove the oxidation. Sometimes that's enough to get everything moving again.

But, since they are paying me for the job ... I polish the aluminum so that there a frictionless surface that the Piston rises and falls against.

You will be very happy polishing the aluminum ... although its tough on fingers if you do it by hand. I spend the time using the Flex-wand made for Dremel that lets me get in there and polish the whole Bore.

Don't forget to knock out the Emulsion Tubes.
Remove the Main Jet and Washer.
From the bottom ... tap-out the Brass Center Tube (Emulsion Tube)
There are 16 -20 small Air Holes surrounding the Brass Tube.
Those holes need to be open and clear for your Mid-range and top-end performance.

Use a Cap Screw having the same thread as the Main Jet.
Screw it into the Bottom of the tube and use a hammer to knowk the tube out the top of the carb.

When its time to re-seat the Tube ... thread the Cap Screw into the bottom, again and pull the Tube into place.

 

Emulsion tube = needle jet. I don't know where I got that term any more, but I read jet needle (silver) and needle jet (brass) got mine to actually look like brass again.

Gentlemen with wives or who do their own mending, I know everyone talks about using a single wire from a brush to clear out those holes but sewing pins work as well (but not needles as they are tapered.)

I actually used an allen wrench with the right diameter and gently tapped the tubes out of the carb, by placing the wrench right against the tube on the underside of the carb and tapping gently with a screwdriver handle. I did this VERY carefully as I did not know whether it would actually take that sort of abuse. I did find it was gentler on the emulsion tube than pushing really hard would have been. I felt like an archeologist trying to dig out a dinosaur bone without damaging, we're talking very light tapping.

Damn I wish I'd called you first. Pigheaded wench! Rereading your technique I like it much better as it wouldn't put any dents on the tube itself, and would just be tapping on the end of the screw. It never occurred to me. That technique could probably be put to use elsewhere....hmmm...

Any special tips for getting the bike started again after putting the carbs back on?

I killed my flexwand last year. Time to buy a new one!

 

Re: 1982 XJ650 Hard-Impossible Start - Seafoam & Carb Cleane

Look, Julie gets it!!! Why can't all the other guys think like this????

AND SHE'S INCREDIBLY REALISTIC AS TO WHAT IT TAKES TO DO THE JOB CORRECTLY (4 hours per carb, rest of the week to finish.....).

I like to start off with a cheap-o brake cylinder Hone that you can buy for a few bucks at any auto parts store, and use it BY HAND (rather than chucked into a drill as is normal). Just keep the stones wet with WD-40 etc. and move it up and down while hand-spinning. The stones on the hone will break up the worst oxidation in the piston bore (whether you can actually see the oxidation or not), and then you can get down with the 400-600-800-1000 grit hand polishing (although if you're careful, you can cut strips of the fine grit paper and wrap it all the way around the hone's shoes, and continue to use the hone as the polishing tool).

Most probably, the starter jets in the carb float BOWL are clogged, that's true on about 90% of the carbs that I come across. That's why the "real" choke doesn't work, and your "hand choke method" does. You've got to get those starter jets in the bowl clean, clean, clean......here's a great thread on that subject:

http://www.xjbikes.com/Forums/viewtopic/t=4050.html


The picture titled "starter-jet.jpg" on the post by FinnoAngelo at 4:33 pm on May 02, 2007 is what you're looking for. That picture is worth 1000+ words of true XJ nirvana.............

 

Chacal,

looked on the link but could not find the picture you referred to. Looked further in at a link about FinnoAngelo cleaning carbs. Still couldn't find it. There's lots of great info in there, but that picture would be appreciated. I'll try again.

 

The picture is in that thread linked to above, on page 2 of the thread, about halfway down the page, within the post by FinnogAngela placed May 02, 2007 at 4:33 pm. You may have to end up reading other parts of the thread to be able to interpret that image completely.