back firing thru the carb

[barefoot11]

Hello! I for some reason thought it was a good idea to buy an 88 supra comp, even tho I knew about stringer problems. but anyway I was tring to barefoot tonight and when running wide open it starts to slow down then if you dont get off the throtle it cuts out and starts back firing thru the carb???? Also after that happens there is oil sitting in the lip of the valve covers????? any thoughts would be great!!

Kory

[OUI]

Here's what I think.

1. Your advance mechanism on your distributor is broken/rusted/sticking or just not working. You can try to get it working again by spraying WD-40 in the little holes on the side. But, I would just by a new and compete ignition set from www.partman.com it comes with a new distributor, coil, electronic ignition, cap, rotor and plug wires for less than $300.00 -- it's a great deal.

2. If you have a Holley carb you need to replace the Power Valve. My suggestion would be to get an entire rebuild kit through www.skidim.com for $80.00 it's cheap and easy.

3. Oil on the valve covers, that's hard to say what that might be -- other than try tightening the bolts on the covers or get some new gaskets for a couple of bucks.

Hope this helps -- good luck.

PS To keep your (new) advance mechanism moving smoothly in the future always spray some WD-40 into those holes while the motor is running every spring and fall.

[DKJBama92Mariah]

A backfire indicates retarded timing as OUI said or a lean condition. Since it only happens at WOT and it stop when you back off, i'm thinking fuel supply issue. Change the fuel filter/water separator and make sure your fuel tank vent line is not clogged.

[barefoot11]

I just got a new fuel filter, was reading in the old posts and saw that (had the canister style)

I got a tune up on it befor I put it in the water and they put new plugs, wires and new distributor cap on it.. do you still think i should spray wd 40 in it?? (dont think the even cared about my old boat)

Talked to a mechanic and he said a valve might be sticking/leaking and pressure is building up in the valve covers and thats why oil is leaking..(seems to be coming from the bolt head and not leaking from the gasket?!? and on both sides) any thoughts about that??

I'm a first time boat owner so I glad to have any advice on this!! Thank you!

[OUI]

Pull the plugs and check the compression with a compression gauge. If one of the valves is stuck you'll get little or no compession on that cylinder. Spraying WD-40 in the holes on the side can't hurt so give it a try. Keep in mind, if you have a Holley, once the carb has backfired you have plown the power valve and you will loose performance.

One other thought, take your boat out with a friend loosen the bolt on the distributor open it up and advance the timing, if you gain speed it's your advance mechanism. You could also check it with a timing light.

[barefoot11]

what compete ignition set did you order from partman.com?? when I looked at it the only one they had was for gm motors??

Thanks

[OUI]

I have a GM motor, I didn't check for Ford. Give them a call and ask them.

[SupraTom]

I have an 85 Comp and had a similar problem. Here's the fix:

New distributor
Carb Rebuild

When rebuilding the carb I found that both the Power valve and secondary diaphram was shot. MAKE SURE YOUR KIT COMES WITH THE SECONDAY DIAPHRAM!!!

Like OUI stated the spring was broke in my distributor I'm guessing you have the same or similar problem. Either way electronic ignition is the way to go.
I went with the blue and silver Mallory distributom through skidim and noticed an slight increase in top end it runs amazingly!!! Much better for barefooting!

Don't forget to reset your timing after all of this.

Before I caught the prop it did 41mph!

[OUI]

If partman.com doesn't have the parts for a Ford check with skidim.com