driving my new speedster out for a ride yesterday , it starting shaking and loss of power , still running , like is is running on 3 cylinders , it is brand new only have 250 miles on it , any suggestion what it night be ?
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plug wire off? gotta start somewhere
Plugged idle jet?
With the engine running pull one plug wire at a time from the dizzy cap and see if the cylinder rpm's drop off, replace and move to the next wire, that would narrow the problem .
As Bob has suggested, start with the easy stuff first. Make sure the coil wire and all the plug wires are properly connected (at both ends), spark plugs are tight (check all 4), point gap is correct (if the distributor still has points), the cap contacts are not totally burnt to crap, the carbs and manifolds are not loose, and the linkage is opening both carbs properly. If it's still running like a bag of poop, pop both valve covers and check that a rocker clip hasn't come off (if it has stock shafts), an aftermarket adjuster isn't broken (and not lifting the valve as much as it should) and all the pushrods are in their cups on the rockers. Guys- did I leave anything out?
Just so you know- an engine with a plugged idle jet will run fine once you get it up on the mains- above about 3,000 rpm. It will only run rough at idle/off idle and the lower rpm's. Once the main jet circuitry takes over you won't feel the plugged idle jet.
Hope this helps. Al
PS- What Alan said too.
One thing to think about before you start taking off pugs and stuff.
I was told ( others please chime in if I’m wrong) but if you have electronic points, like a pertronix, taking off the plug wires will mess it up.
Just adding that in.
Good luck!
Thanks guys I will start with plug wires and go from there will keep you informed
Only thing I can add to Al's list is to do a compression check. You can buy a screw in hose compression tester from Harbor Feight $27. If not electrical or fuel issue, it will give you compression readings - like burnt valve, valve not opening/closing (push rod/rocker), broken piston ring, head seal leak. You're looking for all pistons to be close to 120 PSI - one low at say 80# is a red flag.
Problem solved didn't realize the linkage popped off one of the carbs , still learning
I love it when there’s a simple fix!
Happy driving!
CAPTAIN posted:Problem solved didn't realize the linkage popped off one of the carbs , still learning
The journey is just beginning :")
Glad to hear you got it figured out. And....
IaM-Ray posted:CAPTAIN posted:Problem solved didn't realize the linkage popped off one of the carbs , still learning
The journey is just beginning :")
^^^What Ray said^^^
if ur driving and the car just stops check the wire going from dizzy to coil ,ask me how i know, took me 20 minutes along side road for that one.
CAPTAIN posted:Problem solved didn't realize the linkage popped off one of the carbs , still learning
Glad it was solved quickly and easily.
My advice was going to be to start with the easiest thing first and work your way toward the more complicated fixes. It is almost always something easy. I was cleaning idle jets the other day and when I was done it ran worse than before I started to clean the jets. Right side linkage had come off and it took me less than 2 minutes to find it.
I had a VW powered rail buggy back in the mid 90's. I started out to drive it one day and after a few minutes the engine stumbled and then stopped. I walked around and checked all the usual things and found everything in order. I was stranded on the side of the road and decided to try to start it again. It fired right up and drove fine for another few minutes and then the same, the engine stumbled and then stopped. Same procedure more frustrated now and checking over all the easy things I thought it could be but found nothing that was a possible cause. Again after a few minutes It started and ran perfectly few another few minutes and stopped. I finally found the problem. The buggy had a plastic fuel tank that sat up behind the driver and passengers heads, it had a vented cap with a rubber tube of about 12" coming off of it. The vent tube got bent in half somehow stopping the tank from being able to draw in air as the fuel was sucked out causing a vacuum that was actually collapsing the sides if the tank and finally starving the carb. While I was stopped and looking for the issue the tank would slowly draw air through the kinked vent tube until the tank was back to normal ready to run and start the process all over again. I laughed out loud at the simplicity of a kinked vent tube and the trouble it caused.
I agree, in my experience it is 99.9% of the time a very simple reason for a good running engine to stop running or start running bad.
I can't figure out why everybody is cleaning idle jets all the time.
DannyP posted:I can't figure out why everybody is cleaning idle jets all the time.
Floats disintegrating from ethanol.
In my experience, they last about 3 years, then need replaced. If I just do it, I don't need to rebuild anything. If I try to go a season too long... the idle circuit and transfer ports need soaked and sonic cleaned to get cleaned.
Hmmm, I've never changed mine since 2002. Spanish Webers.
DannyP posted:Hmmm, I've never changed mine since 2002. Spanish Webers.
You're fortunate. Perhaps Weber phenolic floats are better then Dellorto phenolic floats.
Don’t think so. I certainly had to replace mine a couple of times. The black rubbery coating on the floats would start flaking off after a bit.
I haven't noticed any issue with my Weber floats in 6 years. Maybe it helps that I add StarTron every time I fill up.
No ethanol in mine. I either run Avgas or Sunoco race fuel. I think all of our pump gas in Nebraska has corn squeezins in it. Maybe the 91 octane premium doesn’t. I need to check that.
Fpcopo VS posted:No ethanol in mine. I either run Avgas or Sunoco race fuel. I think all of our pump gas in Nebraska has corn squeezins in it. Maybe the 91 octane premium doesn’t. I need to check that.
Yeah, almost all of our gas now has corn juice in it too. Usually if there's ethanol in the pump gas the premium will have the least amount. I know here we have Chevron in Regular (87 octane), Chevron Plus (89), Supreme (91) and Supreme Plus (94). The Supreme Plus is the only gas with no ethanol.
Be Careful running Aviation fuel. The way they calculate the octane rating is different and the fuel is very different than the fuel made for automotive engines.
They sell full leaded 114 octane blue racing fuel out of the pump at many gas stations here in Indiana the racing capital of the country. It has a sign for off road use only but I have and countless others have pulled their cars up to the pump and filled up. I would read up on using aviation fuel to check what I am saying. I don't need to run race fuel now that I have a Subaru powered Speedster but I do use the highest octane leaded fuel I can for the same reasons others have mentioned less ethanol or no ethanol.
Jimmy V. posted:Be Careful running Aviation fuel. The way they calculate the octane rating is different and the fuel is very different than the fuel made for automotive engines...
Aviation fuel was popular (due to costing substantially less than legitimate race gas) with the offroad racing VW crowd a number of years ago around here and I've seen more than a few toasted engines that obviously weren't getting the octane numbers they required. I remember someone saying something about it not being designed for the pressure changes of higher rpm's. It was always a shame to see a nice, strong 2 liter with big valve heads reduced to junk... Al
My car would absolutely run better on the race gas, but there’s absolutely no way I’m going to do that. I like to drive my speedster anywhere I want, not be tethered to a specific gas station where I can get race gas or even ethanol-free fuel. It’s pretty hard to drive any distance from home if that’s your plan.
E10 requires different (fatter) jetting then ethanol-free fuel, so it is just something to be dealt with. Complaining about it and railing against it does not change a single thing, but we’re all prone to do it anyway. It’s sort of like grumbling about the weather.
Regardless, E10 is here to stay (unless we move to E15). If I change the floats occasionally, I don’t have any problems. If I let it go too long, the float start flaking apart.
It’s just not that big of a deal.
My engine is jetted to run on 93 octane E10. Timed for it too. runs great, no problems.