1982 KZ750 N1 SPECTRE Bobber build

Been working on this bike for about a year now. Its an '82 KZ750 N1 Spectre edition. Most of the pieces were not with the bike when i bought it so I decided to turn it into a bobber. Let me know what you think about my progress so far... Any tips are appreciated as well as this is my first bike build.
*The Idea of this build was to make a BUDGET bobber. I am currently a college student and money and time are very hard to come by, so progress on the bike is slow but this is mostly just a hobby I work on in my free time. My goal is to build a custom bobber for as little cash as possible. Right now I have about $200 invested in this bike and its nearing completion. I hope to finish this entire project for under $400. That's including the price of the bike itself!! I picked it up for $175. I didn't know if it ran at the time but after a few months of this and that I got it to fire up and idle with no problem. Engine seems to be in good shape...Oil looks clean, compression is good, trans shifts nicely and all gears are strong. I changed the oil and filter, new spark plugs, rebuilt carbs (WOW they were bad), and replaced one coil. Here it is so far...

Maybe someone can help me out with a couple things...

The Engine will start and idle with no problem at all. It seems to idle very well now that I took apart and cleaned the carbs. It will rev to about 3000 rpm without a problem but anything over that it acts like it is starving for fuel. If i give it full throttle it will cut off every time. I checked the float levels and they all seem top be correct. Also voltage at coils is around 11.5 - 12 volts.

What could be causing this? Sticky slides? low coil voltage?

Sorry, not much help with engine diagnosis, but I love what you've got so far. Love the shaft drive and the angle cut on the frame. Sweet tank and man that things on the ground, I like it.

Nice look bike.

What do you have for air filters? Exhaust? It looks like you have a 4-1 instead of the stock system. You'll need to rejet for sure if you haven't already.

82SPECTRE wrote: ...Engine will start and idle with no problem at all...will rev to about 3000 rpm without a problem but anything over that it acts like it is starving for fuel. If i give it full throttle it will cut off every time. I checked the float levels and they all seem top be correct. Also voltage at coils is around 11.5 - 12 volts.
What could be causing this? Sticky slides? low coil voltage?

Hello, 82SPECTRE, and WELCOME to KZr!

Might possibly be fuel starvation caused by an insufficiently vented fuel tank.

Could test run with cap open to see whether it makes any difference.

But be careful to prevent allowing any gasoline to touch that handsome paint job.

Would also check for obstructed petcock or in-line fuel filter.

Good Fortune!

Here's a little more info...

*Im going with POD air filters as soon as they come in the mail.

*The exhaust is Vance&Hines 4 into 1 header. The rest of the pipe was never found so the header is all that im left with. I did some research and it appears that this is the stock system so I am unsure whether the main jets are correct since it came from the factory with this system. If it did not come stock this way which may be the case as well then I am sure that i need to increase my main jets.

* The frame was cut with a simple grinder and I decided to cut them at real sharp angles so that the cut metal would not show. It also looks better in my opinion and gives the bike a real sharp look.

*The shocks/struts were removed and and pair of welded rigid struts were added. I did this because I wanted that really low stance that is essential for a bobber look. The struts are 8.5" from bolt to bolt if anyone ever wants to make their own.
***Question*** Is there any issues that I might run into using these rigid struts?? I have heard good and bad about them and I just don't want these things falling apart on me down the road. It doesn't matter to me if its a stiff ride, I just want it to last. The bike will be a Sunday cruiser and nothing more.

As for the engine issues.... I do not believe it is fuel starvation. There was no cap on the tank at all when the engine ran before and there was a free flowing line between the tank and the carbs. No fuel filter or anything that may restrict fuel flow. And still it has this issue.

*I have a new battery coming in the mail this week because I suspect the old one may be bad. Maybe this will give some more power to the coils and solve the problem.

I'm not sure about the 4-1 being stock... I thought that was only on the GPZ models, but I could be wrong. If you have no air filters and a header with no baffle or can at all there is no way it will run right with stock jets. Even if the pipe was stock and it was jetted properly, it needs to have air filters...unless it was a drag racer in it's previous life.

apbling wrote: I'm not sure about the 4-1 being stock... I thought that was only on the GPZ models, but I could be wrong. If you have no air filters and a header with no baffle or can at all there is no way it will run right with stock jets. Even if the pipe was stock and it was jetted properly, it needs to have air filters...unless it was a drag racer in it's previous life.

That makes sense. Like I said I bought the bike not running with little original parts and anything may have been done to it before I came along. I also figured that I was trying to tune the engine a little too soon. I'll wait for the POD filters to arrive before I try to tune these carbs any further.
**Since I have 4 into 1 exhaust (with NO baffle), and POD filters, what jet size would be ideal for this setup?

the spectre i had came stock with a 4n1 kerker all black. without an airbox or filters the jetting will be way off my 1100 wouldnt run without the airbox vacuum slide carbs need something to direct the air

As for jetting with with the no baffle and POD's... I have no clue. If someone doesn't answer here, I'd go over to wiredgeorges forum and search around there or even post your question. I think I found some decent info for mine when I replaced my mufflers with a more free flowing slip on. At a minimum you'll probably find a starting point to work from.

As for the stock 4-1, ya learn somethign new everyday!

Still working on this project a little bit at a time. Have not had much time lately to do anything but I continued to tear it down. The wiring harness has been removed completely. I am re-wiring the bike with just the bare essentials. I found a diagram online for this and it is extremely simple. I got the tank permanently mounted with a gas cap and a petcock.

Next on the list is to fabricate a seat pan and make a battery box that will also house all the electrical. Still need POD filters, headlight, tail light, ect. But once the seat and battery box are done it will be rideable.

Does anyone have any suggestions on some type of metal box that would be the correct size to use as a battery box? Ive seen that some people have used old ammo boxes but what else would work?