[Zed7]

Welcome aboard. 🍻
If the bike revs freely above idle I suspect a good and proper carb cleaning will fix it rather than looking at the ignition. The idle circuits are the first to clog.
(BUT, it wouldn't hurt to check both ends of your spark plug wires. Check for corrosion and that they are firmly screwed onto their contacts. I had one wire not even touching the screw inside the boot yet somehow it was still firing though it wouldn't have for long.)

Another thing to check are the valves. Getting out of spec causes starting and running problems.
My money is on the carbs though. It wouldn't be the first time a mechanic didn't do a good enough job.

 

[Zed7]

Yes please update. It helps us all. Carburetors are great but it doesn't take much to mess them up.

 

[Zed7]

I rebuild my carbs in one of those large rectangular foil pans that you buy at a dollar store. It's great for keeping parts from rolling off into oblivion. Plus you can scrunch up the sides of the foil pan to support the carbs.
Don't forget those tiny o-rings on the pilot screws. Easy to overlook.
Looking good. It's satisfying cleaning the carbs to get your engine running right.

 

[Zed7]

Yeah u right, next time i will buy a pan or a tray, now i had to improvise lol. Yes i took out the o rings. They were in a very good shape so i kept them.

Years ago I saved some pans left over from a party so I had them on hand or I may not have thought of it. Now I use them for everything with small parts, especially springs.
My pilot screw o rings were in good shape as well so I reused them (and also mainly because I forgot to order them when I ordered the other gaskets and float bowl o rings, which were probably able to be re-used).
At the same time I adjusted my valves, which were way out of spec, and that helped most with easy start up and running.
It would be a good time to replace the small o ring in your vacuum petcock.

 

[Zed7]

That tube is what supplies air to the clean air system so I'd just leave it in. The exhaust gas passing by the other end is what causes a suction. Leaving it out of the air box opens the tiny possibility of sucking in dirt or bugs which could wind up on the exhaust valves.
The oil on the bottom of the airbox could have been caused by an overzealous oiling of the paper air filter, which you're supposed to do.
There should also be a complete and intact foam gasket on the air filter. If it's not there then over time it has been sucked into the cylinders. If their is an incomplete foam gasket then only part of it has been sucked into the engine. Some of it may be lying on the bottom of the filter box.

That frame can be saved. The 7 is worth it. It is one of the most overlooked and underrated bikes of modern times. It's supremely comfortable and quick enough.

When I rebuilt my forks I spent the extra dough to get the Traxxion Dynamics damper rod kit with springs for my weight. The bike actually handles well now, worth every penny to me.

 

[Zed7]

I would leave it in, but my concern is that the inside is a bit oily (engine oil). Also i am concerned of the all grime on the floor of the box - would it be sucked in to the carbs?

The grime won't be sucked into the engine because it's outside of the filter. I have yet to open an air box and not see at least a little of oil residue. It's from the crankcase breather. Yours looks like more than usual IMO. So maybe it's from over oiling the filter as well.
There's a catch bottle for the air box down the lower right side of the bike. Did you see if it's full?

Also- Was the foam gasket intact?

 

[Zed7]

First, there are two gaskets at the air box. One is a rubber o-ring that should be fine. Just clean it and re-use.
Then there is a foam gasket that is glued to the filter itself. When they get old and dry the foam breaks apart then either drifts down into the bottom of the air box or gets sucked into the engine. Or a little of both.

As for the crankcase breather, it is there to suck the oil fumes and byproducts of the combustion process that slips by the rings. You can't leave that caustic vapor in the crankcase or you will get oil sludge everywhere in the engine and acids eating away at metal parts. (All cars and trucks have them as well.)
And the stuff is nasty. If you've ever took a whiff and breathed in that vapor while cranking over the engine you'll swear you burned the hair in your nose and just took ten years off your life. It is bad. You won't do it again.
In fact you can tell the condition of your rings while cranking the engine with the spark plugs in but no wires hooked up. If you're getting a lot of pumping out that hose, that means compression is getting by your rings excessively, meaning your rings are worn.

If you look in at your engine from the left side of your bike you'll see a little fat hose that comes out of a round cover then immediately turns in to the bottom of the air box. That is where the engine sucks in the crankcase vapor then burns it in the cylinders sending it via the exhaust pipe into the atmosphere to destroy the ozone layer and end life on earth.
You'll also see a small rubber hose next to it which is the hose to the catch bottle. I suspect yours is full and needs emptying.

Just clean out the airbox and make sure the drains are clear. If your filter is old, get a new one and make sure the spongy foam gasket is in good shape.
The main air gets into your airbox through that wide flat snorkel. It too has a foam silencer that should be removed because that foam disintegrates too.

 

[Zed7]

I think i kind of got the idea - the tube that goes from inside of an airbox (previous page pic circled red with number 1) it sucks air from the airbox same as carbs, am i right?

Make sure you read my post #27.

But that 3/4 inch hose you pointed out in the air box is to add oxygen to the exhaust system to help combust any unburned mixture before it leaves the muffler.
As the exhaust gas is drawn out of the exhaust system, by the Venturi effect, it draws fresh air from the airbox which washes over the exhaust valves and the hot gases ignite any unburned fuel mixture. It is the burbling sound you hear on deceleration.

 

[Zed7]

Well alright. 👍
If you can, post up a pic of where you fit the fuel filter.

 

[Zed7]

If you had your valves checked at 15,000 miles and they were within spec, then at 20,000 miles some may well be out of spec.

 

[Zed7]

Agree I am adding it to the todo list. I am just happy it runs so well after sitting for three years.

I bought my zr7S a year and a half ago as a winter project. I always liked them. It was in good shape by eye with 19,000 miles. It had been treated well except for the fact that I believe it never had any regular maintenance including never having the valves adjusted. It's hard to believe but when I pulled the cam cover there were no witness marks anywhere. No evidence that a wrench or socket ever touched those bolts. No gasket sealer blobs. Nothing.
All the exhaust valves were way out of spec or too tight to get my thinnest feeler gauge under.
All the intake valves were out of spec. I adjusted them all to the loose end of the spec.

I wound up rebuilding the carbs, new carb holders, rebuilt the brakes, new tires, rebuilt and modified the forks. You name it. It now starts, idles and runs as new. Love it. It's not fair to say it's my favorite bike but last summer my other bikes gathered a lot of dust. It's such a nice mellow bike, I can't wait to get back on it.

 

[Zed7]

Turbofish.. Outside of an adv bike or a cruiser, I can't think of a bike with more room than the zr7S. It's pretty roomy. (My inseam is 33 inches).
I had a 650 Versys that was maybe roomier and I once rode my friend's 2002 Yamaha FZ1 which also had a lot of leg room.
Ok, so I just named two bikes with more legroom so that negates my first statement.
Here's one more, my old Kawi KZ1000P police bike. My brother has it now because of his bad knees which he can ride comfortably because of the floor boards. He can't ride my ZRX1200 or my z900 because of the foot peg location but he did find my zr7S comfortable (for a short ride).

 

[Zed7]

Are you saying the carbs overflowed gas into the engine? Easy to find out.
First off, the oil level in the sight glass will be over the limit even on the side stand. If you remove the oil fill plug, take a whiff and there's no mistaking the gas smell coming out.
Simply change the oil, put oil in the cylinders as they've been scrubbed clean from the gas. Crank it over a bunch with a rag over the spark plug holes because it's going to spew out.
Then change the oil again.
Make sure you tell your mechanic to check valve clearance.

I think to fit a fuel filter you must first rotate the tee between carbs 2 and 3 downwards so that the fuel hose comes around the bottom of the carbs thus making more room for a filter.

 

[Zed7]

Good one Obo, I forgot about the explosion. ⚡💥

 

[Zed7]

You don't need to rebuild the engine because of gas in the oil if it was not ridden under extreme conditions for a long time. It is more common than you think.
How many miles on your 7?

 

[Zed7]

I see. Have a good mechanic take a look at it. Check the valves and do a compression test. These engines are pretty tough.
If you do need a new engine it usually cheaper to buy a good used one than to have one rebuilt by a pro. But I'm betting a low mile engine are tough to come by.
Then there's always the option of buying a new bike either for parts or to ride keeping your bike for parts. Make one good bike out of two.

 

[Zed7]

I don't even want you tell you how long it took me to scrape the old gasket from my engine. It was brutal.