289 running rough once warm

[GLENN 70]

If you blocked the top of the carby it should stall ,if not it has to be sucking air from somewhere . And I see it doesn't have points

[Husky350]

If you blocked the top of the carby it should stall ,if not it has to be sucking air from somewhere . And I see it doesn't have points

                                                                                                                       Not completely covered, and that's when I left the idle screws 1.5 out which is what I normally run. Once I riches up the idle covering up the carb won't improve the idle

[evan]

The engine will hold it's idle better if I cover up the carb, or richen the idle screws, which to me I would think would indicate a lean condition. I was thinking more along the lines that the fouled up plugs may be due to the plugs not firing when they should, which could riches the mixture in the cylinder, but appear lean at the carb......if that makes sense.

You didn't accidentally knock off a vacuum hose or maybe lose a plug off a blocked vacuum port on the carb or manifold??

Evan.

[GLENN 70]

I'm running out of ideas . 

[evan]

Glenn's run out of ideas??? You're stuffed!! 

Evan.

[Husky350]

Ha ha, everyone's been a good help, always good having different ideas. I'm going to replace the dizzy next, it did get water and possibly coolant on it so I'm hoping that is the relation to the sudden poor running.....hey, you can always hope 

[GLENN 70]

Evan that is so funny I nearly wet myself .   

[evan]

Evan that is so funny I nearly wet myself .   

Funny but true Glenn. Between you & Shaun, we've got round the clock professional support. Gotta be happy with that!!

Evan.

[GLENN 70]

Thank you   

[Husky350]

Well, splashed out and bought a mallory 8352 with their coil…..spent the morning putting it in…..and……..still the same problem

[griff]

Well, splashed out and bought a mallory 8352 with their coil…..spent the morning putting it in…..and……..still the same problem

why am i not suprised!!
borrow a holley carby from someone, throw it on when motor is warmed up and has been misfiring or whatever its doing.
if that doesnt work, wind the drivers window down and toss in a match! 

[Husky350]

gave it another going over with some carby cleaner, and did notice i am getting a a bit of a leak at the throttle shaft. Is this normal?

[shaunp]

gave it another going over with some carby cleaner, and did notice i am getting a a bit of a leak at the throttle shaft. Is this normal?

That's ok I'm not sure how those carbs work, but if they are like a Holley they will have 4 air bleeds in the top of the air horns, these allow air into the metering system as the fuel is sucked out of the jets, smash some carb cleaner down them. One set is for idle one set for high speed, make sure they are clear. Base timing is set at 6-10 with no vac connect yes?

[Husky350]

I set base at 14, anywhere below 12 it feels pretty rough.

[GLENN 70]

You need to try another carby ,and I recon problem solved .  Even tho I don't know the summit carby they still look like the dud Holley with the lift off top . Once you try another carby and find that was the problem ,go buy a Holley 570 vac sec street avenger . Shaun might still have one 4 sale .

[GLENN 70]

14 base ,are you talking timing .  14 in ok as long as it starts hot and your total is at say 32 deg .

[shaunp]

You need to try another carby ,and I recon problem solved .  Even tho I don't know the summit carby they still look like the dud Holley with the lift off top . Once you try another carby and find that was the problem ,go buy a Holley 570 vac sec street avenger . Shaun might still have one 4 sale .

No mate I have a new 670 and a 450 that need a rebuild left. 14 is a bit of advance on a mild engine, this will give it more vacuum and make it richer, more vac the more fuel it will pull from the jets.

[Husky350]

yeah 14 base, it starts fine. Its actually the same base timing it ran best on before this issue also

[GLENN 70]

14 is a bit high ,I run 16 in mine and most of my mates run anywhere from 16 to 20 deg ,but all performance engines .

[Husky350]

No mate I have a new 670 and a 450 that need a rebuild left. 14 is a bit of advance on a mild engine, this will give it more vacuum and make it richer, more vac the more fuel it will pull from the jets.

I tried to run it at 8-10 but it was really rough, even playing with the idle screws did sweet all.
Before this drama, when i set the timing, I remember it didn't like under 10 base. At 14 base(plus 16 vacuum advance) she ran perfectly, right up until 3 days ago

[Husky350]

Well, Im all out of ideas. She can sit there and be a pain in the ass while we take our holiday off in Vanuatua 

Thanks to everyone so far, I'll give chris a call at sms performance when i get back and see if he can diagnose the problem(or undo my f-ups  )

[Husky350]

maybe take out in the back blocks & give it a "Good-ole-rev-tune ""

if it was drivable i would 

[GLENN 70]

I'm still thinking its a carby problem . When Holley brought them out years ago they did have some problems ,but were sorted out . I never bought one just didn't like the look ,did not look like a Holley . Yours is the only one that I know of , but they are around . When I go to the USA , most cars run edelbrocks then performance cars seem to run holleys . I haven't seen a summit carby on anything yet .

[shaunp]

I'm still thinking its a carby problem . When Holley brought them out years ago they did have some problems ,but were sorted out . I never bought one just didn't like the look ,did not look like a Holley . Yours is the only one that I know of , but they are around . When I go to the USA , most cars run edelbrocks then performance cars seem to run holleys . I haven't seen a summit carby on anything yet .

Till now Glen Look like trouble to me,

[GLENN 70]

The only good thing about them was you could change jets by taking the top off ,no having to drain the fuel from the Bowles . They did have a heat problem on some engines if the exhaust passage was not blocked  off on the intake  ,common with alloy Holley s  now . A  half inch heat spacer fixes that if your not running an air gap intake .