MikeD's 1974 GT-750 project

[rngdng]

I run 75-90 gear lube (cheap stuff from Auto Zone or Wal-Mart) in my transmissions. It never fails.



Lane

[MikeD]

Tried to fire the bike up last night. Some fuel weeping slowly from the non-OEM float bowl nut (13247-31210, $3.50, discontinued, $13 on fleabay, crap, don't want to spend money on these carbs...)

As expected there was fuel in the oil. Drained the case well - but what a mess it made underneath, some of the wiring runs right next to the plug so of course the oil followed the path of least resistance. Cardboard caught all of it. Will address all that when the motor gets pulled for cleaning/polishing and wiring updates. Then measured out 2200cc in my ratio-rite mix cup and poured it in but nothing out the weep hole while bike is on the center stand. hmmm.... Added another 200cc, still nothing out the weep hole. Figured I had more then enough new 30wt in there so I buttoned it up.

Then found that the battery was pretty knackered after a few attempts. So off to grab a new one last night and filled it with acid, decided to let it sit overnight to let the levels stabilize when the garage temps hit 30*f/-1C - seemed like a good time to come back in the house and call it a night at that point. Currently about the same temps outside this morning, need another hour or 2 before getting back to install the new battery and have another go at getting it fired up.

[MikeD]

It's Alive

It fired up. Didn't run great, but this should help explain why



Puking fluid from the middle cylinder. Thankfully I'd left the cardboard from last nights oil change on the floor to catch any lingering drips. Going to put an old dish tub that I use for cleaning underneath the middle pipe split connection to catch as much as I can along with more cardboard to get it cleaned all the way out.

Went out and grabbed some new 5/16-8mm clear fuel line. I was trying to make some old kart fuel line work, and it cracked in the cold at the carb fuel inlet point. One of the float bowl connector lines is weeping too so I guess I'm resigned to pulling the carbs again and going back through them. Meh

More to come

[rngdng]

If you need carb parts for BS40s, let me know.....I have a few that I will never use.



Lane

[MikeD]

If you need carb parts for BS40s, let me know.....I have a few that I will never use.

Thanks Lane, let me see what I need and I'll def be in touch about this, appreciate the offer. Thinking right now a float and the bolt at the bottom of the float bowl, but let me get the beast fully on its feet first and more will become known then.

So went back out and fired it up. L cylinder not firing, pipe is cold and as it warmed up the bike started to run worse, bogging. Not crisp on the throttle at all. Killed it and pulled the plug and grounded it and hit the starter. No spark. Pulled the coil pack out, going to clean it all up. Some green corrosion on the plug wire off the L coil where the plug cap screws in. Will cut it back a bit and reinstall the cap after checking the ohms on it. Tomorrow

Happy New Year to all

[Alan H]

I always fit no resistor plug caps to my bikes. Every little helps!
If you're just running in the garage, put some 1 grade hotter plugs in 6s instead of 7s (NGK), they're ok for a run around the block too, but not long distance.

[MikeD]

Finally got it running on all 3 cylinders, and have heat in all 3 pipes. Had to do some plug juggling that, for some reason, solved the L cylinder not firing even though it had spark. :shrug:

The L cylinder white wire off the points to the coil was the problem. It's a horseshoe style connector (just like the one on the condenser) and one of the legs was missing and it wasn't attached well to the points so there was no connection, so nothing happened when the points opened. As I was tracing the wires between the points and the coils it took me more than a few seconds of staring at the wires in the area under the L side cover to figure out that the 3 wires coming off the points to the connector there had no male connector body - the spades were just plugged into the female plug "... wth, this just doesn't look right.... <pause> oooooohhhh, huh <note to self that this will get cleaned up with the rewiring>"

Carbs are still lean on the idle circuit at 1/4 turn so it bogs out and dies after a few moments off the choke. Idles cleanly for a minute or 2 till it leans out and dies off. Carb tuning day tomorrow.

Did a compression check - L: 100, C: 115, R:105

Baby steps, baby steps

[MikeD]

While I've been quiet for a few days there has been a bunch of progress.

Now that the GT is proven to run I've moved the R1 down off the bench and moved the GT up. The stock pipes are off getting ready to be sold off to help offset the cost of new Jemco's. Pulled off footpegs, shift arm, and the swingarm.

Have had a roller 92 GSXR750 in the way in the garage for 3 years that I'm finally getting to use as a donor for the GT. Got the swingarm pulled out of the roller, and have it installed into the GT, needed 2mm cut down off of each pivot boss face - dirty work. Going to reuse the skinny GT pivot bolt and going to machine the fatter GSXR pivot bolt as the adapter sleeve, brilliant idea I thought.

Need to get the sprocket face cut down on the donor carrier quite a bit to get the chain to clear the frame. The sprocket on the carrier right now is somewhat offset so that will help. Once I figure out how much offset I have with the carrier face cut down I'll need to find a source for offset front sprockets. Planning on running the 3 spoke alloy wheels for the time being to get the suspension shaken out, then look into the spoke setup in phase 2.

Front end is coming off later today, need to see how close the 92 steering stem is to fitting and either have it adapted or have the GT stem pressed into the 92 triple. Ernie my machinist is going to be busy.

Tank is finished with its electrolysis bath. Used regular baking soda instead of the washing soda, seemed to work ok. If not I can run it through again. Coated the inside with about 200cc of 2 stroke oil that is sitting in there now that I roll around in the tank when I walk by it now and again. Came out ... ok. The fuel filters will tell the final story once it's on the road after running a few tanks of gas through it.

Built a list of socket head bolt sizes that I'll need for the engine cases to try to order in A2 stainless through the local Fastenal store.

Currently thinking that the paint is going to be Lexus Jade Green. Had the color on a 92 SC400 and loved it, hoping it will work well on a bike, we'll see. Everybody does that blue which looks great, but I'm looking for something different.

Put an email message into Autocar about sources for a Newtronic ignition, we'll see if I get a response. Found the guys at http://www.motorcycle-ignition.com.au/m ... ei_kit.htm" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false; who sell the Newtronic, they've got the ignition kit for $296 AUD (212 USD) + $28.25. Any other places to purchase at? I see Marcel at classicsuzukiparts.nl has a unit for $199 plus €19 shipping as well

Hoping to get the Jemco pipes and electronic ignition ordered this week.

[jabcb]

I do like Jemco’s nickel finish. Are you getting the 3-into-1s?

Here is a pic of mine with the nickel finish — they blue up a bit that looks fine too.

[MikeD]

I do like Jemco’s nickel finish. Are you getting the 3-into-1s?

n, 3 into 3, but unfinished. will clean them and then do the MopNGlo treatment

[MikeD]

This thing is coming together fast, but I still have a sense of the 90 10 rule, just not sure where it will show its face yet.

front end is off, roller ball races driven out. AllBalls steering head tapered bearings placed on order tonight and should be here Thursday I hope. Anybody need front end parts?

I'll be soooo glad to be done with all the rust and grime and dirt and grease and oil spread everywhere on this bike that ends up on me, the workbench or the floor. I must go through 8 pairs of the blue nitrile gloves a session. The sooner this frame goes to the media blaster the better.

Jemco's go on order tomorrow morning, still hoping to get the electronic ignition ordered this week. Took a closer look at the seat, not sure if the foam up front has degraded or if it's just the way the cover was put on.

That's it for tonight, will get some new pics up soon

[tz375]

With the appropriate Allballs bearings, those forks should slide straight in.

For ignitions, I have used a Newtronics and it was OK. I laso used a couple of custom DYNA S triple ignitions which work really well and this time around I bought a Accent ignition from Germany for a lot less than a Brit unit via Australia.

Several people on this site have used the Accent and swear by them. Much better build qiuality than Newtronics and no Black Box to worry about.

Here is a post about it. http://oldjapanesebikes.com/blog/2012/0 ... on-system/" onclick="window.open(this.href);return false;

I emailed Uwe at his web site and ordered one and it arrived shortly after.

http://accent-electronic.de/ELZ2Coil.html" onclick="window.open(this.href);return false;

[MikeD]

With the appropriate Allballs bearings, those forks should slide straight in.

For ignitions, I have used a Newtronics and it was OK. I laso used a couple of custom DYNA S triple ignitions which work really well and this time around I bought a Accent ignition from Germany for a lot less than a Brit unit via Australia.

Several people on this site have used the Accent and swear by them. Much better build qiuality than Newtronics and no Black Box to worry about.

Here is a post about it. http://oldjapanesebikes.com/blog/2012/0 ... on-system/" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

I emailed Uwe at his web site and ordered one and it arrived shortly after.

http://accent-electronic.de/ELZ2Coil.html" onclick="window.open(this.href);return false;

just dropped an email to Uwe, hopefully he'll catch it before closing time

[MikeD]

it doesn't appear that the ELZ2Coil supports individual cylinder timing does it?

[tz375]

Correct, but in the real world that is not an issue unless your crank was rebuilt by a monkey who could not get it correctly phased. On a stock street motor timing is not as critical as people might have you believe