XJ650RJ Seca Build

Chacal has been great in helping to get me the correct parts to replace those busted carb boots. Hoping it was just a bad batch. I’m contributing it to my “luck”.

I’ve got the carbs rebuild and floats set, and brake calipers rebuild. Unfortunately this weekend won’t contain any orogrsss as I’m out of town, but next week everything should go back on the bike.

Fingers crossed that my hard work pays off. I’m also going to be replacing the exhaust / header gaskets at the motor as I realized these were overlooked during my rebuild.

 

So the weather in san diego started to get good, only to start raining again. I've managed to get a little work in. I'm still having some issues with the front tire bead holding air. I broke the bead seal to try to correct the issues the other day. after a few days i'm not noticing any loss of air pressure, so we will see how long it holds. Worst case, I will just have to put air in the tire twice a month.

The good news is that after the final carb rebuild with an ultrasonic cleaner, the bike runs a lot better. I did a quick vacuum sync yesterday and got the bike in a manageable range. I plan to (weather permitting) to use the colortune to dial in the air fuel mixtures. I was at 2.5 turns and felt that it was a tad lean. So i turned each one around 1/8 of a turn and feel that i'm running a little rich now. I've noticed a little more of a gas smell from the exhaust.

The main issue i'm trying to resolve now is a slight hanging idle after a rev. It takes about 3-5 seconds for the bike to return to idle after raving up to around 4-5K.

 

You have a vacuum leak somewhere.

 

I’ll take another look but my last few attempts to trace any source of a leak down have been unsuccessful. Every possible location or part failure to cause a leak has been replaced through Len

• New oem manifold boots & plugs
• Vacuum line to petcock
• Rebuilt petcock
• Throttle shaft seals with washers
• Airbox to carb clamps (rubber sleeves are still good)

I’ve tried with propane and all sorts of sprays. Any other recommendations or thoughts to check while I go over it all again?

 

How did you attach the new manifolds?
No gaskets?
Just gaskets?
Gaskets coated with a gasket sealer?
(the latter is highly recommended)

Vacuum leaks can sometimes be difficult to find. How are you checking?

 

that ain't good enough, if it ain't right it's wrong

 

Just the manifold and gasket. I’m checking with propane and slowly moving the gas around in specific areas to see any increase. Focusing on throttle shaft, manifolds and airbox boots. I’ve also repeated this with sprays. The only area which I’ve gotten any result in was if I sprayed around the lip of the airbox lid. But you had previously mentioned that it isn’t the cause of a leak.

 

So after a 15 minute ride to get the bike warmed up, this is my "benchmark" the idle is returning quicker than it was yesterday. Its not terrible, (its a lot better than it has been), but its not as perfect as it can be.



I quickly hooked up my color tune. Unfortunately I wasn't able to actually adjust any air/fuel mixtures at this time. Simply a reading of what each plug / cylinder was doing. While having the color tune hooked up, cylinders 3 & 4 would get white burst while some slight backfiring was happening. This was not replicated when the colortune was removed. What does this correspond to?

 

sounds good, is the cable hanging up maybe?? cause its idling smooth.

 

Vacuum leak. Could be that the copper crush washer on the colortune needs to be replaced. Could be that you have an intermittent vacuum leak elsewhere, which would explain why you haven't found it yet. If the leak was at the intake manifold flange it could be sealing up as the bike warms.
Another possibility is the vacuum port caps. I think you got those from Len, but it's still possible that one or two aren't sealing properly. Did you get new clamps for them as well?

Most of the times that I've run across this problem it was solved by using a gasket sealer on both sides of the intake manifold gaskets. Even though the mating surfaces were clean and flat, and the gaskets new, there were still enough small imperfections to allow leaks.

Permatex makes a spray-on copper gasket sealer that has been good for me.

 

Worst case, you can just sell the bike to me and be done with it

 

Yes I bought new clamps and caps from Len. I will try and remove the intake manifolds and use the gasket spray. Hopefully I can keep the same gaskets which were installed a few weeks ago. I know I’m lens catalog it says they must be replaced every time, but we’ll see if I get lucky. Then I can rule that out as a possible source. I think I have a can of that exact spray on gasket material.

I’ll look into another copper crush washer for the colortune if I can find where to source some.

I’ve also got an old set of the rubber caps, if the problem persists after replacing the gasket seal, I’ll start swapping the caps to see if that solves the problem.

 

The gaskets should be fine to reuse (with the spray), unless they tear.

 

So I was able to reinstall those gaskets per your suggestion and this appears to have helped.

After building an aux gas tank I was able to do a proper carb sync and colortune on all for cylinders and she runs the smoothest she ever had since I bought her. I ran out of sun light and didn’t want to ride in the dark. So I’m saving the test run for today. But signs are looking good.

 

Onto the next issue -___- at least the silver lining of this is that after all of this is done, I will know this bike inside and out. haha

So Cylinder 1 is no longer firing. After pulling the plugs, I see that the plug is covered in gas. I've verified that I get spark, and that compression is even across all 4 cylinders. So this leads me to a fuel issue. So I will be pulling the carbs to double check everything. I did a fuel level check on the bike and noticed that the level was a tad low if anything. So I will pull the carbs and re-go through them to ensure that nothing bad made its way through the fuel line into the carb.

 

Well, I figured out why after getting the bike synced and running, cylinder 1 decided to stop. I found this inside of the float bowl when I took it out to inspect something. No wonder cylinder 1 was drowning.

After re-installing, I finally got all 4 cylinders to fire. Tomorrow will be for re-tunning everything. Fingers crossed this will be the last one.

 

I make my own intake gaskets...I have a roll of thick gasket material, a fine tip Sharpe marker and an xacto knife with a new blade, use manifold as a template trace around , and cut the gasket material to shape. The home made gaskets have worked great I put a smear of grease on both sides , if I have to pull manifold will come off easy . Your bike is coming along good.

 

todays activies:

• Carb sync
• Colortune
• Carb sync
• Oil change

After today’s activies the bike runs much smoother. I noticed a hint of gas in the oil. I’ve verified that my petcock is not leaking. So I’m hoping this came from cylinder 1 being flooded with gas while the jet came out. I plan to put some miles on the bike and then do another around round of colortune and another sync. After that it’s time to buy some new rear shocks to replace the factory ones.

 

Hagon shocks are a good upgrade but are not cheap.

 

Is it safe to assume if while the bike is idling, i fresh down on the sync screws and the idle drops that my butterfly plates are not properly set / sealed? Or is this back to the never end cycle of chasing an air leak?

 

Removed the card and reset the butterfly plates on the carbs. I noticed 1 had a little more light shining through than the others when the rack was broken. So I reset that. While I had everything in the bench, I rechecked the fuel levels and noticed 2 were just outside of spec. So I spent some time to get all 4 exactly at 3mm.
Over the last few days the bike has run much better. Still not 100% but deffinetly close.

 

What are you using to sync the carbs? spray starter fluid on the carb body where any leak is possible and on manifold boots to make sure everything is sealing properly. If it shoots up in rev that's where the leak is or around. Go slowly and make sure all excess fluid is wiped up.

I use a pair of hagon shocks on my bike an di am happy with them. Being 6'1" at 235 they work well.

 

So after some time I’ve gotten the bike dialed in. After a few additional minor updates to the carbs the bike is running the best it ever has. Took it out for a 100 mile ride over the weekend. She did great even on the freeways, and especially great during some backroad detours.

 

I picked up a complete XJ900 oil cooler setup. I plan to get that installed on the bike here shortly but needed some confirmation that I wasn’t able to find so far.

My understanding is that with the XJ900 oil cooler on a stock XJ650 the mounting hardware won’t line up. That’s fine, I plan to build some custom brackets anyways. I eventually plan to upgrade to the spin on oil filter, but until then, am I able to use the XJ900 oil filter as I have the complete XJ900 setup that includes the oil distribution plate, and the oil filter cover assembly. And then at a later date then I can swap out the filter housing with the spin on? Or are there issues with using the XJ900 oil filter components on the xj650?

 

Yes!

The XJ900RK/RL components are the same as used on all XJ650/750 models which used the factory cooler. The later version XJ90o's used a different type distro plate which may (or might not.......) work properly on the other models.

Yes!



The only issues that you may run into is the cooler hoses...........those are pretty specific to individual models because of their shape and length, the metal pipe part of the hose assemblies are pretty specifically shaped to fit particular frames and to have the proper length to reach the cooler location. Check your clearances around the exhaust header pipe(s), you don't want the metal tubes portion of the cooler hoses to get to near the header pipes, will defeat the purpose of an oil cooler!


P.S. cool pictures!

 

Thanks for the info. I’ll make sure that the line lengths work out. If not I’ll try to scout out some shorter lines. Fingers crossed.

 

So I got my XJ900 oil cooler delivered yesterday and got to cleaning. Not too bad for a finished result after some degreaser and paint. I did a quick mock-up / text fit and everything should line up. I will need to create a custom mounting bracket. So once that’s done, I can get this installed. The fresh paint should help match the painted engine, as well as replacing all of the mounting hardware with matching new chrome Allen head bolts.

 

Looks good.
If I did that I'd have to strip my whole bike down for restoraton so it'd match.

You will also need to modify the hose keeper, or get the correct one for the 650. The mounting holes are a lot different on the 650, in that there are two of them instead of one. When I ran the 650 Turbo cooler on my 750 I didn't bother using the hose keeper, and it worked out fine, so you might consider that option.

 

Oh good point, I didn’t check the positioning of the hose keeper. I will have to look at that when I build the cooler mounting bracket and see what work I’ll need to do for that. Thanks for the tip.

 

So I attempted to install the oil cooler today. Unfortunately I ran into a few fitment issues. Due to the bike having wrapped pipes from the PO which I initially liked the looks of, once I got the plate installed between the engine and the oil filter, I realized that I would not be able to get the oil filter on/off without removing the exhausts. Since I don't really want to remove the exhaust pipes every time I have to do an oil change, I realized I would have to wait until after I pick up the spin on oil filter conversion. But the good news is that the hose keeper positioning works out perfectly. So one day after I get the spin on oil filter, I will attempt to re-install the oil cooler. For now, it goes on the shelf.

But first, i still need a new set of rear shocks. Been looking at the progressive 412-4008B/C shocks. They are the same spring rate as the 12.5 shocks, but 13 shocks. I'm leaning towards this as my rear wheel gap as decreased due to my custom seat pan, as well as me being over 200lb's when i'm on the bike it could use with a little extra travel.

So future projects for the seca:
1. Re-wire the hand controls (the moto gadget m-button is acting up due to interference and giving me false turns signals)
2. New rear shocks
3. Spin on oil filter
4. Install oil cooler

Until then, at least I can enjoy the bike.

 

A few updates have gone into the bike over the last few months.

I've re-wired a portion of my custom wiring harness with the Motogadget m-unit. I have been experiencing some issues with the m-button that allows you to run 6 wires for all of the bar controls in a single wire. There was some interference from the coils as the wire has to run right by it. I was able to find a solution to resolve my turns signals from randomly turning on/off. This was a huge safety hazard as I constantly had to look at my gauges to see if my signals were on. Plus, a portion of the wiring harness is MUCH cleaner than it used to be. Using some multi-pin Molex connectors, and some heat shrink tubing I've made a nice custom wire harness for the hand controls. Next step will be to re-do the other half of the wiring harness to clean up everything a little more too. I might wait until I upgrade the battery to a lithium ion so that I can move the smaller batter, and the m-unit into the battery box.

I was able to source a spin-on oil filter. This allowed me to install oil cooler setup which I recently purchased. The install went well, after making a custom mounting plate since the XJ900 has a different setup than the XJ650. I'd recommend both of these items to anyone thinking about them. Oil changes are now that much easier, and the oil temp on the bike is now better managed with the oil cooler installed.

I'm also going to be removing the pipe wrap which came installed on the bike. This might come back to bite me, as I'm unsure of the condition of the pipes under the wrap. But the wraps are extremely dirty, and do not compliment the bike now. So hopefully the pipes will be in a decent condition. Worst case, I can re-do the wrap.But i'm hopeful that the headers should be in a decent condition as the exhaust pipes are in relatively good condition.

I'm still working to dial in the carbs to their perfect point. I've gone through this whole thread and re-read all of the comments. I've realized that I've overlooked a few pointers which people were addressing on my colortune issues. I will be checking how the colortune is effected when using the enrichment circuit. This is a test that I have not done yet. The issues I'm running into when trying to colortune are that some of the cylinders will not get a proper spark, or it is intermittent. I also feel like when using the colortune the bike does not want to idle as well compared to when the bike without the colortune. On my next wrenching day, I will setup my go-pro and record all of my results in case there are still any issues so that I can share with everyone here for some feedback as all of the info is greatly appreciated.

My main symptoms of the carbs are it takes a little longer to warm up than i feel it should. And even after it is fully warmed up, if I'm sitting at a light at idle, I have to constantly give the throttle some little blips to keep it from dying. So i'm hoping if I can get the colortune to actually read proper results I can get all of the air/fuel mixtures setup correctly and resolve this issue. I've bought some replacement copper washers to use on the colortune to see if this helps with the issues I've had. I'm trying to get my MPG above 25 which i'm currently averaging after 3 tanks.

 

When using the colortune plug I had number 3 cylinder was intermittent on the plug , I took off the cap and trimmed wire and threaded back on ,problem solved. I just went through mine went for a 180 mile ride ,when I filled up.and ended ride I had went 87 miles and fuel indicated on Atari 3/4 of a tank ....so was pretty happy with mileage . 3 of the plugs are brown number 2 gray so might be a little lean but want to put more mileage on to see what it looks like.

 

I was able to spend a few minutes today and trim back the wires on the coil wires to rule that out. While I was trimming the wires, I took a reading of the secondary side wires of the coil (without the caps) and I have a 15.5K resistance on both coils which is way outside of the acceptable range. I did test all of my caps and I have 5.2K on all of the caps. So this is putting me around 5k over the "ideal" resistance of 21k as I am at 25.9K. And around 1k over the upper limit of the coils and the caps combined of 25.2K.

With too high of a resistance, this would effect the quality of the spark. I assume that I should get this situated before continuing to any other steps? I will check and see if I can source some coils from an xj650 parts bike. I had made the jump to an aftermarket cb750 set per some recommendations here, but it looks like this batch may not be the best solution for me.

 

9-21 update: I am now a year old, and thus wiser. haha

I am looking into a few options to purchase another set of coils as my coils are over the allowable tolerance. I've sent out a few PM's here to get some test readings on them to see if they are good. Otherwise, we'll have to check eBay. While i'm waiting, I've tested my pickup coil to confirm that everything is in spec, and thank goodness it is. Upon a closer inspection of my TCI box, I snapped this photo. Do these solder joints look "OEM"? or does it appear that someone has been in here before?

 

It looks awful. There's as lot of green circuitry missing, too

 

That's not kosher.........

 

Anyone have an extra 650rj TCI (TID14-08) laying around they want to part with?

 

It looks to me like it was painted over after the soldering was done. I've seen similar sealants used on control boards from a different sort of machinery.

 

Use an ohm meter to check continuity on the traces. I suspect that everything's fine in there.

 

Yeah.... Gotta agree. I can see it better on my iPad.

 

Okay thanks. I’ll check it out tomorrow and see what the verdict is. Fingers crossed it’s still good.

 

I do not like the solder on the 4th one down from the top, though. Looks waaay overheated

 

So I tested all 9 pins from the side of the TCI to the solder posts (?) inside. All tested with perfect continuity. However, 1 item which I noticed was that pin 4 (from the top, the one which hog fiddles noted looked too hot and also cleaned up after with some work) which is associated to the Red & white wire for the coils (12v) and pin 5 & 6 appear to all be common (pin 5 is unused, but 6 is for the black wire which goes to the pickup coil, which I believe is the ground). I had around 1K ohms of resistance between pin 4 & 5/6.

info at https://xjbikes.com/forums/threads/what-does-each-wire-do-thats-from-the-tci.24035/

from the photo included; pin 5&6 are Pickup coil ground.

I'm not sure if this is expected. Any one else with a TID14-08 able to verify? Ultimately looking to see if I need to spend around $100 on a another TCI, or if this is intact still good.

 

Found a new/used TCI on eBay which had a better circuit board than mine. So in a week we’ll see if that helps with the problem. Now I just need to find a good set of used coils.

 

What gas tank did you use? Looks great. Doing the exact same build to a 1982 xj650 turbo.

 

It’s the stock tank off of the Seca xj650rj. If you’re looking for 1 in the US, hey are rare since the bike was only brought here for 1 year.

 

New coils and new TCI came in the mail today. Tested them, and the. Threw them on the bike. Instant startup as opposed to a second or 2 with the old setup. I let the bike idle for a few minutes. Over the next few days I’ll take it out for a ride to fully warm up and then see how the colortune reads.

 

Personally, I went with a brand new ignition box over a used one.

You are still replacing one 35 year old circuit board with another 35 year old circuit board. No telling how long it will last.

 

So frustration update:

I've moved and now have access to a real garage, so I've set up the bike in a spot where I can really go through everything. So I've been determined to fix my hanging idle issue. After some intense searching for an air leak, I noticed a small leak after spraying starter fluid on 3 & 4 carb intake boot. So I remade manifold gaskets, sprayed with copper gasket maker, and then for extra assurance, put some RTV around the edge of the boot, gasket,head.

Unfortunately I still have a hanging idle after the bike is warmed. I took it for a quick 10 minute ride after letting it warm up on idle and when pulling back into my garage the bike idled at over 4K.

I've verified that my field levels are all in spec at 3mm, all jets are cleaned, and I cannot trace any additional air leaks. I'm at a loss of what to do now.
- Valves are in spec (when I last checked them about 100 miles ago)
- Compression is good across all cylinders (don't have the specs in front of me)
- Carbs are re-built with all new parts.

 

Adjust the idle speed when the engine is fully warmed.
Can you get it to drop down to around 1100 - 1500 RPM?