Annual weber adjustment?

[Scott R]

I do run my 911 over the winter, mostly at idle to keep the battery up when it's been on the tender too long. But last weekend was pretty nice here in Colorado so I drove it a few miles.

It seems like my carbs may be out of adjustment after sitting. I have a bit more decel popping then I remember, and my idle seems to be a bit rough at times. Other times the idle is fine, but it dips every few stops.

Should I be going in and adjusting again? I would have thought nothing had changed over the winter without any driving. Also this is new gas, old was drained and used in my snow blower.

BTW, performance is still amazing at WOT and it still pulls very hard.

[JP911]

The carb bodies should be cleaned. I would pull them off the car and wash seafoam through the passages and jets. You may also want to flush out the fuel filter. Also, low-pressure compressed air (either from a compressor or keyboard cleaner) can be used as an extra step to clear all the junk out.

[Forza]

From a mechanical standpoint, the carb setup, linkage, etc. shouldn't go "out of adjustment" as a mere consequence of storage. Unless you have a really, really crappy linkage setup, which I doubt. How old are the Webers? There might be some mild deposits here or there--maybe a can of Seafoam and an Italian tune-up are in order!

It could also be that weather conditions, etc. are somewhat different now than when the car was originally stored, but I had twin sidedrafts on a BMW 2002 here in Boulder and never had any problems across seasons or altitude changes, other than the expected rise in engine temps (within acceptable limits) as altitude climbed. Also, various posts here give the impression that Webers can be a bit finicky on 911s (relative to PMOs).

[RWebb]

sound like it might be too rich

before anything major, I'd [a] run something thru it with the carbs in situ, [b] see if the popping was at higher altitude than you remember (less air, right?), [c] change spark plugs, check timing/dwell, [d] run the H out of it to "clear the tubes" via an "Italian tuneup"

[Matt Monson]

Could it be because we're still on winter gas here with higher than usual ethanol content?

[Scott R]

Webers are a fresh rebuild from last summer. The linkage is suspect now that I think about it. Everything is from PMO, but I think I need to check the return springs and possibly add a spring on the rear link. I'll have a peek at that tonight.

I've not done anything to clean them as Randy suggest however. I didn't look at the filters and as far as I know there was a few months of dust on top of everything when I took it out.

I'll check the timing, change the plugs and give it another try. Thanks guys.

[rgrimm]

I haven't messed with the carbs on the '68 for at least 10 years. The mechanical linkage really should go out of adjustment once it's set.

Mine always stumbles when I first take it out, other than at WOT. It takes at least a take of gas and an "Italian tuneup"...then it runs like a top.

The idling over the winter probably does more harm than good in terms of fouling things up. I just let mine sit. The other thought is that if it's anything like mine, carb'd engines really don't like cooler weather, which may have some impact on what you're experiencing. It's been an early Spring, but it's still not that warm...

[Scott R]

Originally Posted by rgrimm

I haven't messed with the carbs on the '68 for at least 10 years. The mechanical linkage really should go out of adjustment once it's set.

Mine always stumbles when I first take it out, other than at WOT. It takes at least a take of gas and an "Italian tuneup"...then it runs like a top.

The idling over the winter probably does more harm than good in terms of fouling things up. I just let mine sit. The other thought is that if it's anything like mine, carb'd engines really don't like cooler weather, which may have some impact on what you're experiencing. It's been an early Spring, but it's still not that warm...

I should also add that yes it was only about 60 deg F, and my 911 runs COLD even on the hottest days in the summer. And when I say "cold" it never breaks the 1/4 mark on the temp gauge, and most always sits around the 1/8th. Probably not the best environment for carbs I suppose.

[teenerted1]

replace the filters
and blast some carb/brake cleaner through the jets and you should be fine.

maybe check the plugs/points just to be safe.

[911pcars]

Run some FI cleaner through the fuel system (tank). Could be fuel deposits that have developed from sitting in storage.

Do the simple stuff first. Spray carb cleaner through available orifices (carb orifices that is). Overhaul carbs as a last resort.

Sherwood

[RoninLB]

start up carbon on plugs never being cleaned off

imo

[red 2.7]

I had the same symptoms here in cold Montreal and just swapped plugs and filed the points and then she runs fine. Spring start up is pretty smokey till the car warms up then it's ok for the rest of the summer. don't take them apart till you try the simple stuff. I use a set of plugs for storage and start up and put in another set for the season. good luck

[SCOTITUDE]

Stop running the car to charge the battery. i leave mine on the tender all winter with no issues. causes more problems by running it at idle then shutting it down and letting it sit again. old days i was told it would screw up the carbs on my bike. varnish everything up then needed to clean it all in the spring. im sure its the same. i just put on carbs last year so no winter idling to hear the motor in january cause i need a fix.