Bombsquad's 1993 GS500e refresh

[bombsquad83]

I bought some xylene and some MEK.  $35 bucks later, I went home and poured a little into a bucket and plopped in a big flake of the old coating to test.  The xylene by itself did basically nothing.  Added the MEK and it maybe softened it up a bit, but nowhere near dissolving it.  I'm getting a bit fed up with this thing...I might as well try these solvents in the tank since I have them.  I'm going to wait until I get the old petcock from vasama and then seal the stuff in there for a long time for maximum effect.  If that doesn't work, then I might try a paint stripper again.

[bombsquad83]

Engine is back in the bike now.  Old chain is ground off.  Gotta get this tank done.  It's killing me not be able to ride.  It was 65 here today.

[bombsquad83]

Put carbs and muffler back on and attempted to fire her up with a bottle as a temporary tank.  Jumped it from my car (without the car running).  She would only run on the right hand cylinder.  I switched the plugs and still the same issue.  I didn't have time to get into it any more than that.  I got at least some spark with the left plug up against the frame.  Anyone want to help narrow it down for me?

[bombsquad83]

Well...here is the plan.  I don't have a compression tester, so I will have to save that test for later if I can't figure it out otherwise.  I already pulled the carb and adjusted the left side float height a bit.

1. Clean all electrical connections to make sure that I'm getting good current flow.
2. Switch coils from one side to the other
3. Electrical diagnostics tests.  Not sure what all is involved here, but I have the Haynes manual so I'm sure I can find some good tests there.
4. Clean out the carbs once again (did all new seals and jets last fall, and drained the fuel from the carbs during the winter, so I doubt this is the issue)

Any other suggestions?

[bombsquad83]

I cleaned some electrical connections and switched the coils.  At first, still the same result.  It was only running on the right hand cylinder.  I messed with the idle screw a bit, and it eventually started running on both cylinders.  I even got it to idle for a moment on just the left hand cylinder after it warmed up.  Revving slightly up to 5-6k and she came back down a pretty slowly to idle.  Could be because I didn't have the airbox on the bike...  Also, I might have a slight exhaust leak since I didn't replace the header gaskets when I put the exhaust back on.  Also, the choke seemed to have almost no effect on the rpms. 

<venting>
I'm so flipping paranoid with this thing.  I'm also worried about my valve job not being right after all the pulling the cams on and off.  I think of anything and everything that could go wrong, and I can't seem to attack things one by one.  I'm all over the place and frustrated.  Between the tank and carb and other issues...ugh.  It kills me every time I see a bike out riding.
</venting>

[ninjeff]

I cleaned some electrical connections and switched the coils.  At first, still the same result.  It was only running on the right hand cylinder.  I messed with the idle screw a bit, and it eventually started running on both cylinders.  I even got it to idle for a moment on just the left hand cylinder after it warmed up.  Revving slightly up to 5-6k and she came back down a pretty slowly to idle.  Could be because I didn't have the airbox on the bike...  Also, I might have a slight exhaust leak since I didn't replace the header gaskets when I put the exhaust back on.  Also, the choke seemed to have almost no effect on the rpms. 

<venting>
I'm so flipping paranoid with this thing.  I'm also worried about my valve job not being right after all the pulling the cams on and off.  I think of anything and everything that could go wrong, and I can't seem to attack things one by one.  I'm all over the place and frustrated.  Between the tank and carb and other issues...ugh.  It kills me every time I see a bike out riding.
</venting>

Tell me about it man! It was freaking gorgeous here today, and i saw a number of bikes out. Hell, even in my parking lot there were 4 bikes out from winter storage. I even got a message on MY bike from another tenant asking if i would sell it!

I can't ride right now either cause of the carb issue and i havent registered it yet. So, instead i sat on it and made vroom vroom noises. 

[bombsquad83]

The more I have thought about it, I think my issue could have been mostly due to old/bad gas.  I need to figure out whether the coil wire that pulled out of the coil is an issue as well before I get it completely ready.

In other news, my friend tried some kind of soy-based paint stripper that he uses in his woodworking business on a flake of that old coating that is hanging on in my tank.  He said after 4 hours the flake got very soft and started to fall apart.  This might be the ticket to get the tank cleaned out before the new coating.

[bombsquad83]

Progress!  I used this soy stripper that I got from my friend, and I've got it all stripped off the inside after letting it sit in there for a whole day (24+ hours).  Still have to get some big chucks and small flakes and a few random BBs to get out of the tank before moving on with the POR-15 process.  Pics to follow tomorrow.

[willi777]

 After seeing the junk on your petcock, i would suspect some of it got into the carbs and is blocking one of the jets. Might wanna take off the float bowls to see if there's any evidence of it there.

[bombsquad83]

Everything in the carb should be pretty clean.  I cleaned it up and replaced all the jets at the end of last year when I was trying to get the bike running better, and I drained the carbs completely for the last 3 months.  Only ran the bike with the gas tank on a couple times, and wasn't having the same issues then.  I will be giving them another once over if I still have the same issues with some new gas.

In another note, after doing some more research this old coating is definitely POR-15, just applied very poorly by a PO.  They left large pools of the stuff in the bottom of the tank in some areas instead of draining the excess, and from everything I've read you shouldn't have the non-adhesion and flaking issues with POR-15 coating unless you do something wrong in the process.  This stuff should be a "lifetime" coating.  No wonder it was harder then heck to get out!

[bigbad1ton]

Great progress. I hope to go through my bike after this season. Hit the left carb with some carb spray or starting fluid. If it starts hitting then you know if it's fuel or fire.

I have been fighting carb issues for awhile now. And after reading a thread here found I was missing the vacuum O-ring beside the diaphragm.

[bombsquad83]

I have been fighting carb issues for awhile now. And after reading a thread here found I was missing the vacuum O-ring beside the diaphragm.

Yeah, that is a common problem, which I've already dealt with before.

I've made more progress with the tank.  The soy gel did great.  After rinsing it out with water several times and once with acetone for good measure, I loosened the last few big chunks of the old liner manually with a long steel stake.  To get them out of the tank I took advantage of their sponginess and stabbed them with a drywall knife and yanked them out with needle nose pliers.  Now there are just a few little sections of the old coating hiding out in the crevices and corners of the tank.  I'm not to worried about those.  If they haven't come out by now, the new coating should hold them in and seal around them.  Now some pictures!

Here is my homemade way to block the petcock hole.  Just a piece of wood cut to size and holes drilled in the proper spacing.  Then fold up some aluminum foil tape for a gasket.  Worked great!


Here's the tank after the soy gel was rinsed out.  Still has some big chunks to get out.


Had to do some tank some tank drying to get the last few flakes (and the remaining bb's that were hiding out stuck in the crevices) out with some more gymnastics.   A shopvac in a blowing configuration worked great.  I supposed you could use it in suck mode too?

Here you can see the biggest chunks that I got out with the drywall knife stabbing method.

I even borrowed a cool flexible camera tool from a coworker to check those corners of the tank you will never see.  Yeah I know...I'm anal retentive.  There are still some old flakes of liner in the corners.  I'm over it at this point.


Lovely rust ready to be treated and sealed off forever


I boiled some water and mixed it in Marine Clean for the next step in the process.  It's diluted about 2 or 3:1.  I'm agitating and rotating the tank around every hour or so until bed time and let it sit overnight.  I put a light metal chain in there along with some random screws.  No more steel BBs!  Those things were kind of a pain to get out... Tomorrow one more rinse with the last of the Marine Clean, and on to the Metal Ready and the sealer!

[cbrfxr67]

Fzantastic job on pics!  (applause)  Bosch videoscope,..nicenessss!  I love my Visual Optics videoscope.  It's one of those things that is great to have when you need it.  Shopvac idea is a good tip too!

[bombsquad83]

Took apart the carbs and soak the bodies and the float bowls in carb cleaner for an hour or so.  Couldn't have hurt anything at least.  I also confirmed that the new needle valves that come with the K&L rebuild kit are indeed shorter than the ones that were in my bike when I got it.  Not only that, but the valve seat is also slightly different.  The new needle and seat would not close properly even with extreme adjustment to the float height.  When check the float height with external gas line to the carb drain, the gas level would be much higher than it should be.  I ended up using the new seat with the old valve needle.  I was able to get the gas level correct on one carb, and just slightly above the gasket on the other.  Seems like whatever i do with the tabs/float height, it doesn't seem to have the proper effect on the actual gas level.  If this set up doesn't work out, I'm going to order new OEM needle valves and seats.

I also started the acid step on the gas tank.  Going to be turning the tank and letting eat away the rust that is left, then hopefully sealing tomorrow!  More pics coming soon.

[bombsquad83]

Here are some pics of the carb cleaning process.

Dipping the carb in cleaner

What all the parts of a carb look like, other than the body of the carbs themselves


Back to the gas tank sealing process.  Here is picture of the tank still wet after the last metal ready acid step.  Still some rust in there...hoping it will be ok underneath the sealant.


I had some trouble getting that stupid chain out.  It got wrapped and knotted around the water drain tube, and also one end got deeply stuck in a crevice of the tank.  I finally got it out, had to really yank on it.  Had to beat on the corners of the tank to get all the screws and remaining flakes of old liner out of the crevices. 

Here is a picture of my drying set-up.  Two C-Clamps and the shopvac.  Worked great, about 3 hours later the tank was definitely bone dry.

Dry tank


Put in the sealant next.  Rolled it around to cover all the sides, then drained as much as I could.  I'm letting it cure up side down so that the thickest coating will be on the top (unlike what the PO had done before).  Cleaned out the threads on the bottom q-tips. I will have pics of the finished job later in the week. I think it's looking pretty good.

While I was waiting for the tank to dry, I had a couple other things to take care of.  I needed a spacer on the CRF250X petcock to put it in a more reachable position, and to lock it in place.  I made this spacer/adapter out of wood and a screw that a ground the tip and the threads off the end.  It matches the little nipple that comes out of the stock petcock to keep it in place on the mount.  I painted it black.


I had to use a longer bolt, but it mounted up really nice and tight.  Now the petcock doesn't move around when you try to use it, and it's in a great reachable position.

Fuel lines still run nicely behind the frame.


I also sanded down my old rusted, battery acid corroded battery box.  Then I treated the rust with some CLR and rinsed it and hit it with some acetone and alcohol.  Then I sprayed it with some flat black rattle can I had laying around.  Came out alright.

[cbrfxr67]

This is going great.  Really liking your thread sir!  Applause for pics!  I got a 900rr tank that I'm going to have to do something like this to.  Another way I like to dry out my tank is put my heat gun on low and set it up to blow right into the opening.  And 'why not' use a piece of wood?  Makes sense,....hmmm

[bombsquad83]

Thanks CBR.  I would use a welder and drill press if it had access to them at home, but hey, why not wood?

[bombsquad83]

Installed my battery box and routed the wiring harness.  Used some nice thick weather strip to pad the battery box.  Gave both ends of each connector a squirt of WD40 (I assume this would help get a better connection?).  I also realized that my neural light is apparently burnt out all of a sudden.  Add another part to order to the list...

[bombsquad83]

Looked into the tank tonight with the videoscope.  Here are the pictures.  I think it came out ok, but you experienced POR guys tell me if this looks ok or if something is wrong.  I think it looks ok on the bottom, but the sides and top are not completely silver and have some texture to them.  Please give feedback if you feel necessary.






Alright guys, done with the tank (hopefully) and moving on.  Got some other things done tonight.

Replaced my burnt out neutral light.  Lucky that I had a bulb laying around that was a similar size.

Bought 12 new stainless steel socket cap head bolts for the carb.  Replaced all those horrible JIS bolts.  Just a dab of blue threadlock on each of the bolts that went in the brackets holding the 2 carbs together.


I mentioned that I routing the wiring harness on the left side of the bike.  I'm not sure that it's correct...  Take a look at this picture and please let me know how this is supposed to be routed. Nevermind, I found some good pics that BaltimoreGS posted.


I put the carbs back on and the airbox and fired her up.  Now...here is the issue.  It was only running on the right hand cylinder again to start!  Once it warmed up, or if I revved the engine, the other cylinder would kick in.  At first it needed the choke just to run, then after it warmed up the choke didn't seem to do much.  In fact, it seemed to kill it a little.   So, what do you guys think?  I have already switched the plugs and the coils independently to no effect, so that is out.  Here are some possibilities I'd throw out and please add or subtract from the list if you can help.

1. Need to sync the carbs
2. Air mixture screws (3 turns right now)
3. Planning on replacing exhaust header gaskets (not sure they are bad, just old and the header has been on and off)
4. Float Heights.  I have been having trouble with getting the fuel level right no matter what I seem to do with the tabs.  I think I might have to bite the bullet and order OEM float valve sets.  I know it's right on the right carb, but might be just a bit high (1/8" higher than the gasket) on the left.
5. Electrical issue other than plugs or coils
6. Almost forgot compression test.  Can I borrow a tester from autozone or something?

[bombsquad83]

Synced the carbs...didn't help at all.  I also checked the float heights using a tube on the drain method.  They were both fine. 

EDIT: Here are some picks of the carb syncing device made from aquarium stuff just like the $5 dollar plan from the wiki. It was really $12.  Call it inflation.


Had to stretch the tubing a bit with some needle nose to fit them on to the carbs

This the gang valve (actually a dual gang valve, but I'm only using 1 valve), along with the 2 T connections.

The water in the tubing on both sides.  Basically just get these level with the engine warm and idling at around 1750 by adjusting the carb sync screw on the throttle linkage.  Started with the gang valve open for coarse adjustment, and then closed it down slowly for finer adjustment.



I think something bad is going on with that left cylinder.  I borrowed a compression tester from autozone, but it didn't have the right adapter for the threads (too big).  I did a quick thumb compression test on the left and I couldn't hold my thumb over the hole, so I assume there is at least some compression there. 

I realized that once it is warmed up, the left cylinder will only run when the choke is OFF.  This is why when I turn the choke on the rpms don't change that much.  It goes down to running on one.  I also messed with the mixture screw on the left all the way up and down and nothing seemed to help. 

1. Need to sync the carbs - This is out
2. Air mixture screws (3 turns right now) - Didn't improve
3. Planning on replacing exhaust header gaskets (not sure they are bad, just old and the header has been on and off) - Don't feel any obvious air leak, and I don't think this would cause the issue I'm having.
4. Float Heights.  I have been having trouble with getting the fuel level right no matter what I seem to do with the tabs.  I think I might have to bite the bullet and order OEM float valve sets.  I know it's right on the right carb, but might be just a bit high (1/8" higher than the gasket) on the left.   I checked these, they were actually fine on both sides.
5. Electrical issue other than plugs or coils - Could be?
6. Almost forgot compression test.  Can I borrow a tester from autozone or something? - Still need to get the right adapter

What do you guys think?  I need some help here!