What wroung with my engine!!

i have another thread on here saying my problem but nobody is writing back. i took off the carbs and plug the carb #1 hole and put a hose on the brass barb at the top and blew air into it. the air went some were so i turn the engine over and still the air didn't stop so are my valves shot because this happened to all my cylinders. i have a 82 seca 650 engine and nothing else custom harness which looks like it is working right but i never seen it run it just back fires and pops through the carbs

 

If its a YICS Bike, the Air will escape to the other Manifolds.

You need to do a Compression Test of Each Cylinder.

Search: Compression Test

 

ok thanks

 

ok i got around 140 psi is that good or bad

 

At this stage of the game.

That's Excellent!
It's within a few PSI of Perfect.

 

so then what can be the problem i just blew off my carbs from the back pressure and it sounded like it wanted to start and how can i test to is if all my valves are closing all the way

 

If your getting 140 psi your valves are closing. I dont think valves are your problem. Have you cleaned the carbs? Changed the plugs?

 

i have cleaned the carbs a lot but it doesn't seam to get gas into the cylinder and when it does it will back fire then if i open the chokes it will back fire through the carbs. i haven't changes the plugs because they look and fire good but it keeps getting black soot on them.

 

Black soot = to much gas. Go get some new plugs ther cheap and thats what it took to get mine going. It was doing the same thing yours is.

 

ok thanks ill go get some tomorrow you know where i could get some in stockton california thanks

 

ok i found some 2.98 each aint bad. how positive are about this you think this will get it to start

 

ok i got some spark plugs. can someone tell me what they are gaped at

 

ok it didnt start it got more poping with starting fluid but nothing. could it be the coils how can i test them

 

ok i think it is the coils. but i cant afford it so do you think two car coils will work i already tested it and it puts out a very good spark

 

Car coils could work if you get ones with appropriate primary and secondary inductance and resistance. If these values are wrong the results could be weak spark at one end of the range (under-dwell) and blown TCI unit at the other end of the range (over-dwell).

Do you think both coils are bad? If so, why do you think that?

By the way, if you do need coils, I have the old pair (known good) off my SECA 750, that I could sell you fairly cheaply.

 

My home made spark checker. Copied it from one that we used at the boat shop I worked at in Houston.


If you lived around here I'd come by and help you get it going. If its popping its getting some fire. Are you sure you got the wires correct. One coil goes to 1-3 the other goes to 2-4 I think. And your sure you have gas in the bowls. When I did my carbs I had a dee dee dee moment and put the floats in upside down.

 

i think it because it kinda looks weak and if i put gas right into the cylinder it wont pop if i turn it over and i hooked up one coil off a four cylinder car and it sparked alot better than the coils off the bike. how much you want for them.

how you make that and what does it do

 

Spark from XJ coils is anemic at best when cranking. I think you're barking up the wrong tree.

I think you're right, your valves aren't closed when the plugs are firing. It's not a valve problem though (compression rules that out). Your problem is in the ignition system. Your plug wires are either switched around or the coils are swapped where they plug into the wiring harness.

The spark plug wires from one coil go to spark plugs 1 and 4. The wires from the other go to 2 and 3. If it's like that unplug both coils from the wiring harness and switch them around.

 

We've discussed this possibility before... also suggested a timing light to verify that 1/4 is firing when it should...

Scrappy - any news on this front?

 

no i just kinda figure why cant car ignition work since it spark good.

well the orange and r/w coil goes to 1 and 4 because it is small and 3 and 2 go to the gray and r/w because it is longer an because it has the cylinder # it goes to but there is the possibility i switched them on the ignition box(the black box forgot name) because the diagram doesn't say were exactly the wires go just what they connect to

 

Well, a timing light would tell you for sure.

Swapping the R/W+O and R/W+Gr plugs to the coils may also help.

I can't tell you for sure which color goes where because I replaced all that wiring when I swapped to Microsquirt and GM Saturn coils.



If you really want car coils, though, you might want to look into pulling a pair of coils from a Mazda Miata. These have built-in igniters, so you could then rig the TCI box to switch them on and off with pull-up resistors. Dwell may still be an issue, though. At the worst, you'd blow the ignitors, but keep the TCI box.

Another coil I had thought of trying was the one used in four cylinder Subarus. It's basically a pair of two-tower coils in a single package. The main reason I went for the Saturn coils instead, though, was that Subaru uses some kind of weird HV terminals.

Other solutions, like switching to a aftermarket ignition system, will be more expensive.

 

i already hooked up one coil i had and it sparked but i don't have a spark plug wire that splits into two because i was planing on using 2 coils like the original and hook it up the same except place the r/w wire to the positive and the negative to the TCI box for the signal to tell it when to fire. it worked but could check to see if it would run because didn't have that spark plug wire so all i seen was the spark across the top

 

ok i have great news i just fixed it. it was the coil wires i switch them were the coils plug in and that baby fired right up scaring the crap out of me thanks all you guys that help

 

ok now there is another problem number 3 isn't firing and number 4 exhuast fells hotter than the others