82' 750 Resurrection

I found with my '81 Seca I had to give a lot of attention to the stock connectors. If they didn't do with a thorough disassemble and cleaning I replaced them with new, or just soldered the joints with heat shrink. Also replace the stock fuse box without a doubt. I personally used in-line fuse holders that have an LED that lights up when the fuse is blown on that holder. Prior to that I was constantly chasing random electrical problems. Since. Few to none.

 

Looks like I was a little late on this reply. New to the forum.

 

Meant to get an update up last week but here we go!

Forks are done! Won't post all the details but will share pics of which parts get replaced in a basic rebuild kit from Chacal. I decided to block off my Anti-Dive valves and got the plugs to do so.



Also if you did not know where the Upper Cushion Gasket goes, it is above the air joint, below the triple-tree bracket:


Onto the tank and fairings!

Here is some of the solder work I did on the tank:



Sanded flush and no more pinholes or leaking.

Removed more rust from the outside of the tank and need to finish it up with some 600 grit before applying bondo.

Rear headlight housing was sanded, primed and sanded again. It is ready for paint.



Side covers were also sanded down and then primed. Still need to wet sand before they are paint ready:



Rear fender/license plate holder was taken apart, rust removed from metal parts and then painted. That is ready to go back onto the bike.




My paint order arrived yesterday along with other supplies. My goal in the next day or so is to fully prep the tank for painting. Still need to finish sanding and then apply bondo and well sand again. Hopefully by the weekend it will be time to spray paint and clear!

 

Mail call and paint update!!

Got my new battery in from Len along with some other small items. I will get it installed once it's fully charged.


Painting is complete! Very happy with how the tank and plastics turned out. First time using body filler and you can't even tell there the dents and dings were.

Paint was supplied by ColorRite and I used 2K clear.



Still need to wait about one more day before wet sanding the clear down then onto polishing and wax. I have all the parts for the tank re-build so that will also be done before going back on the bike.

Here is a semi-first look of the bike with tank and plastics on

 

Looking good so far!

 

Like that look.

 

Shes ready!!

Wet sanded, applied compound and polish to tank and plastics!



Installed the new petcock kit, and gas cap from Chacal



Now I am no professional but really happy how the paint turned out. Could use a little more sanding to get that mirror finish, but will do that another day.



Threw the new battery in, connected the tank, primed and she fired right up! Few minutes to settle the idle (still need to fully tune the carbs) but sounds great!

I did notice one thing with the gas cap, pretty sure it is suppose to vent the fumes but it's not...major pressure build up. The gas cap pops when you go to open it.

Any ideas?

 

Rebuild the cap.... the ball vent and/or air filter are clogged

 

It's brand new from Chacal...should I dig into it?

 

Contact him..... in the unlikely event you either got a bad one, or accidentally got one for a california model

 

Chatted with Chacal and after taking apart the cap and cleaning it very very well, I believe the issue is resolved. Tank no longer keeps pressure in and is venting out the cap.

Seems the aftermarket cap had a different design with 2 ball bearings vs 1 with the OEM cap.

Below this "seat" there is a smaller bearing which I guess had some debris in there which was stopping the air flow.



Still going to keep an eye on it.

I will get some better pics of the bike outside to really show off the paint

 

Took her out for a spin today! Still need to tune the carbs for smoother throttle. Love the way she sounds!



Good thing I was not far from home as I realized the battery was dying (tried to start up after taking pics)...running some tests indicated that my headlight draws some serious power when the bike is off. About 0.01 v per second with the bike off....possible lemon battery? (hope not)

Charged the battery back up and ran the bike. Sitting idle I read about 14.5v at the battery, which I believe is about where it should be. Revving up to about 2k and its pushing about 14.8.

Bike off and I let the battery sit for an hour or so and its reading 12.55v. Going to see what it's at in the morning but considering it has sat in the garage and fired right up I don't think there is a voltage drain.

As for the headlight, I will probably go the route of getting a handlebar switch to turn the main low beam on/off. This would save power and only use the headlight when needed.

 

It would be best to keep it stock with the headlight relay that is already installed. The headlight will illuminate when the bike is started. The relay does latch, so if you shutdown with the kill switch of side stand while in gear the headlight will remain on until the key is turned off. Installing a switch is creating a hazard as the headlight needs to be on for daytime driving for your safety and the switch introduces the opportunity to forget.

 

My headlight has a set of LED DRL's which I will keep on all the time, BUT if I find the battery is just bad a switch may not be needed.

Voltage on the battery showed 12.44v this morning, so that is a drop of .10v overnight. I am going to perform a draw test to see if any current is being pulled with the bike off. Otherwise I may need to reach out to Chacal about the battery.

 

Confirmed that battery is old/bad and working that out with Chacal.

Gave vacuum syncing a shot today and really couldn't get it dialed in.



I take it the main concept is to get all the cylinders about even with vacuum. Is there a certain number to aim for when at idle?

All my fuel screws are set for ~2.5 turns out, which I did not mess with. I have a colortune on the way and figured that needs to be done first before trying this sync again.

Bike idles ok-ish. Sounds like one cylinder decides to come to life every few seconds or so. This causes major bogging when riding until you open the throttle up a good bit.

 

Doesn’t matter what number they’re at.....you want them to be even with each other.

you may have issues with colortuning or syncing......I wiener back through your posts, and I’m not seeing where you took the carbs the rest of the way down to do the throttle-shafts seals.... they’re old—very good source of potential vacuum leak

 

That will get you a ticket. All motorcycles in the U.S. post-1978 are required to have the headlight on whenever the engine is running, DRL's /Angel Eyes or not.

 

Yup did that (page 5), as it was a early suspicion of mine that they needed to be replaced. I'll check for a leak though with some carb spray.

 

Noted. Not going that route now since full headlight functionality will be good with a fresh battery

 

Spent some major time on the bike today.

No signs of a vacuum leak. Used start fluid around the boots, carbs, etc. and no change in RPM's.

I was able to track down that no. 3 was the one that kept dying and coming back to life. Given this I decided to pull the rack and thoroughly clean no. 3, ultrasonic and all.

Performed another bench sync (twice actually) to try to get them in the ballpark.

Cleaning seemed to solve no. 3 from being finicky. First start jumped to 2K and I dialed it back down to just above 1k. Lowering it more causes some "chugging" where doing a colortune sync then vacuum should solve that.

Happy with how the idle is now and my (cheap) gauges needed to be tuned themselves during my check. So all are pulling around the same vacuum, nice sewing machine sound.

 

Idle speed is 1,100 RPM (minimum), but they tend to idle better closer to 1,500 RPM (which also makes cold starts easier). Set idle speed when she's fully warmed. You may need to adjust it a tad during a ride, but don't lower it too much or you'll have it set too low when cold.

 

Been a few days since an update, was waiting on my Colortune and worked on my exhaust...also got a new toy...

Bike was pretty loud and I figured it may be time to re-pack the mufflers...turns out there was no packing left which then made sense.

Ordered 2 "MuffPack's" off eBay which includes steel mesh, steel wool and fiberglass layers.



Pretty straight forward to perform the repacking. This bike came with aftermarket slip on's which are Cobra F1R's.

Removed each side from the collector and separated at the clamp. Tapped out the baffle with a wooden dowel, these were pretty rusted in there (little heat helps).



There was some left over packing on one of the baffles (like one fiberglass chunk), that was it....cleaned them up on the wire wheel and removed rust present on the inside of the muffler where the baffle sits.

Onto the packing. First was the steel mesh wrap, followed by the steel wool. This was then bound together with provided metal wire. Final step was adding the fiberglass. Layers of steel wool and fiberglass needed to be trimmed to fit the length of the baffle and leave enough space for the baffle taper to fit.



Everything was pushed back into the muffler carefully and aligned/tapped back into place. Back on the bike they went and WOW what a difference! Just by the sound in the garage it cut the noise down by almost half.

Now it doesn't sound like I am crazy revving it up even when it's just at idol.

Alright, onto Colortune and another round of carb syncing. All carbs set to 2.5 turns out and were tested. At idol all are burning that nice Bunsen blue. Blipped the throttle and saw it flashed yellow and a gradual increase remained blue.

Given first time doing that I believe that is all correct...left all of them at ~2.5 turns out.

Back to carb syncing, I dialed in each gauge on one cylinder first to make sure they were all reading the same. Hooked all 4 up and 1 and 4 where off a little. So synced 1 and 2, 3 and 4 and then 2 to 3. All 4 are now pulling same vacuum at idol and when revving up to above 2k.

Took her out for a spin and I think I still need to adjust my idol speed a little higher, she bogs down until you give a good amount of throttle. Response at 1500k is wayyyy better and she just want to go. I'll mess with it more this week and keep riding around.


New toy added to the garage this past weekend as my buddy and I finally got our lift! Harbor Freight 1000 lb lift with the Pittsburgh wheel chock mod. Wish I had this thing a while ago.

(On the bench is the XV750 Virago engine which has compression and electrical issues. Need to buy a used front cylinder head unfortunately, bolt snapped off and we have been unable to remove it. Ebay it is! )

 

And after you do that, then you can do the starter repair.........the first time of many———

 

Yes the XV is a Box O Rocks for sure. Even though its the "newer" gen starter

 

Well, solved my issue getting her tuned in....

Broken spark plug...I have no idea how but during another colortune session cyl No.3 ran a whole lot better with the colortune plug in it. Looking at the spark plug I noticed powder falling from the insulator and then it literally separated from the bottom part of the plug..



So there's that. New plugs all around and I will keep the other ones as spares. I take it cyl No.3 was running intermittently since it couldn't produce constant spark.

Dialed in the tune to have the mixture screws to 2.25 turns out. After riding around I think I will lean them in a 1/4 more since idle wants to rise up still (even after adjusting during ride).

My choke actually works properly now on a cold start and when warm causes idle to rise vs bogging it down.

Only able to cruise around at about 30 mph (in neighborhood) but good throttle response and in 3rd gear I can quiet her down a bit to just about 1k RPM.

Added a new key chain because why not. Pretty proud of this build as it's my first and have more plans ahead!

 

I would not adjust them leaner. It may take awhile of fine tuning the idle speed. As it get warmer outside, it may tend to raise the idle, so back it off in ever tiny amounts til you’re happy. As colder weather approaches you may have to ever so minutely bump it up a bit. I keep mine right where it idles how I want it in the 75-85 temp range if it real hot it may go up a bit, in cold weather as it drops lower than I like — I just keep a very slight load on the throttle.

Sounds like you’re getting sorted though!!

 

i concern myself with the idle speed for exactly how long the red light lasts

 

Been a while since I've posted but here is a video link to taking her out for a short ride!



Trying to figure out my cheap speedo's gas gauge. Settings are either 2 wires or 3 wires, which this bike only has 2. On setting 2 it reads nothing, but with 3 it reads half tank when empty. So added 2 gallons and it shows roughly 3/4 full.

A little annoying since now half tank is technically empty and I am not sure if adding resistors would help. Reading 145 ohms with 2 gal in, which is accurate. Thoughts?

Eventually going to swap this one out for a Acewell but would like to get this one more accurate for now.

 

maybe add your own ground wire then flip flop wires

 

Ok figured it out with some trial and error using resistors.

By setting the speedometer fuel sensor setting to "2" on this particular unit and adding a 120 ohm resistor I was able to finally get proper fuel level readings. Added about 2 gallons and got half tank reading, emptied tank until reserve is needed which leaves 1 bar. If the gauge starts flashing it means your reserve is low.

I take it this gauge reads a lower ohm threshold than the stock 25-300 ohm unit sends.




In addition poking around on some more info on this gauge, even though I have it set for a 4 cyl engine, the reading can be off. Switching it back to 2 cyl my RPM's read much better and actually it was off by about 500.

So now my warm idle reads about 1200 RPM where before it was reading under 1K and I kept bumping it up to get to the 1100-1500 range where it really was sitting close to 2k (LOUD).

Working on my buddies helmet cam set up but I will get another ride posted to where you can actually hear the engine without wind noise.

 

Thanks for the ohm resister information, I am doing the same thing to a Seca. I guess I can do that as well, but I was going to just use the trip mileage gauge. As far as the RPM's going , that gauge looks to be the same as mine, off Amazon. It is not very responsive and I do not think it is very accurate. Again, thanks for the great info and good luck with the rest of your project.

 

Try setting menu 3 back to 2. It's actually the number of coils not cylinders as I found in my research. My tac is pretty responsive and with what my idol is set to now the bike runs very well. Still dialing in the tire circumference setting as my speed jumps all over the place and so far it has not been able to read over say 45mph.. Circumference of the 100/90-19 tire is 2081.62, I just reset it to this number and need to go for a ride. True tuning will be with a GPS for speed and adjusting up or down.

 

the magnet has to pass over either end of the pickup, not the middle. the closer the better, i'd say 5mm max

 

For the speedo I did the mark the tire and floor measurement. Mark the side of the tire and mark the floor, roll the bike until the tire makes one full turn. Measure that distance, change it to metric and put that in the speedo. Worked great for my BMW project, it was right on.

I will swap that over to the coil number instead and see if that makes the change. Thanks for the info.

 

I have a magnet triggered speedo on my KTM. Best way is to put a dollop of mustard on the tire and roll the bike through a revolution.
Then measure the distance between the mustard spots. Ketchup looks too much like another grease spot, yellow mustard is best LOL!

 

Nice flag.
Cheers, 50gary

 

Hey guys! Been a while since I've posted but here is a first ride video of this build!

She's a little boggy on the low end in 1st gear, my sync is not perfect and waiting on a YICS tool to come in for assistance with that. Overall she ran great!

 

Hey you didn't tell us it was "R" rated - stupid bridge

 

Only straight roads??

 

Warmer weather is upon us!

Took the bike out a few times and back on the lift for further work. First was oil change and now onto final phases.

Tires need to go along with what I assume are the stock bearings...fully stripped the wheels as they will be going for sandblasting and powder coating.

Bearing puller made easy work as well as a tire changing kit.



New Dunlop 404 tires from 2Wheel.com. Got them to me the next day.

(Virago 750 motor was rebuilt over the winter, fixed compression issue in front cyl and she now runs. That bike is going to be a large project which I will eventually make a new post about.)



New wheel bearing kit for front and rear which I'll install after power coating.



Among my list of to-do's is strip and paint my front fender to match new paint color and replace the OEM shocks.



Also need to order a new front MC (TC Bros) due to the cheap one I originally got does not handle dual brakes really well. I've bleed the brakes at least 5 times and can never get firm pressure. Overnight zip tie method didn't help much. Brakes do work but not where they should be.

Looking forward to riding in warm weather for once!

 

Ok time for me to ask for help yet again.

While my wheels are getting powder coated, today I went over the bike again specifically checking on Cyl 4 for oil consumption.

Pulled plugs and 4 was super oil fouled. Other plugs looked decent, 1 was a little carbon fouled.



Decided to run a cold compression test and see what we got:

Cyl 1 - 128 Psi
Cyl 2 - 135 Psi
Cyl 3 - 135 Psi
Cyl 4 - 140 Psi

I feel 4 has the highest due to oil in the cylinder and I am kind of surprised at 1 for being the lowest.

I acquired a jug set a few months ago that is in way better condition than the current one on the bike:



I guess my main question here is should I just tear the top end apart now and swap jugs? Could get this done in a day or so and I am already waiting on wheels. Not sure what further troubleshooting or suggestions there are to solve the oil eating/low compression. Cold start is super rough still as in it takes a few min of starter, throttle and choke to get her to stay running and warm up.

Plus side from today's work is my front fender is now painted and cleared. I'll let it fully dry before wet sanding/polishing.

 

Update!

Went ahead with the jug replacement and glad I did. Major difference with this set than the previous. Bike starts easier and overall sounds better running.

Shoutout to Len as always for the new gaskets and other parts!



Ran the bike on the lift a number of times and measured my valves again. Ended up swapping 2 shims with each other and all others are within spec!

Had to replace one of my cam caps from the intake cly 2 side as it looks like I torqued it too much last time. Noticed at idol there is a slight tapping noise coming from right side, which research shows could be related to the new cap and its clearance with the cam. No big issue...I hope. Noise goes away when revving up/at speed.



My wheels just came back from power coating (took over a month). Installed new bearings and fresh Dunlop 404 tires! Added new rear shocks and lowered about an inch.



Oh my does she look good...



At this point I believe this rebuild is complete. There are still things I want to do on this bike but I will share in new threads (i.e. Speedo upgrade, M-Unit). Time to get on the road and break these new tires in!

 

looks good!

 

I hope you let the bike go overnight cold after running before checking the valves. If you run it even as a “fire it up, shut it down, then measure....”, you’re gonna have inaccurate results.

 

Yup measurement was done via cold engine

 

Nice work! Looks and sounds great, makes me want to go rebuild my bike again hearing that sound.