SU Dash-Pot Oil

[CaptDon01]

Recently I removed the dash-pot cap on my TR3B and added oil to just below the top. The car now won't start, turns over, has spark, just won't even stumble like it's trying to start. Even tried some starting fluid in the air cleaners, and nothing. Did I possibly over fill the dash-pot's and this is causing a problem? Thanks.....(I'm still learning)....

Don

 

[Dave Russell]

Hi Don,
If you added oil to just below the top cap, it's way overfilled. The oil level should be about 1/4 inch below the top of the inner tube which you can see as you look down into the top. Might need a good light to see it. If you can feel hydraulic resistance when inserting the dampers/caps as they near bottom, there is enough oil in them.

I really can't imagine this situation being so bad that it won't even fire, but there is a first time for everything. I would be suspicious that something else happened during the process.

If overfilled enough, the oil "could" work it's way through the intake & foul the plugs.

Another slight possibility is that you interchanged the caps/dampers on the carbs & the dampers are binding the pistons/air valves. You could try swapping the dampers if things are binding.

First, reach in through the air intake on the carbs & lift the pistons with a finger. You should feel a bit of spring resistance & some hydraulic resistance from the dampers. When released, the pistons should drop quickly & hit bottom with a click. The dampers are a one way valve & they don't delay closing. Raising the pistons will push any excess oil overboard. You may wish to later remove the chamber tops & clean out the excess oil. Don't interchange the tops or pistons between carbs.

Pull the sparkplugs & if they are oiled, clean them with spray brake cleaner. Crank the engine over with the plugs out to clear excess fuel or oil, put the plugs back in, & give it a try.
D

 

[bluemiata90]

Just a thought, what kind of oil did you use. If it's regular motor oil or some other heavy oil. It my be keeping the carb pistons from lifting. Just something to consider.

 

[Paul Johnson]

[ QUOTE ]

Pull the sparkplugs & if they are oiled, clean them with spray brake cleaner. Crank the engine over with the plugs out to clear excess fuel or oil, put the plugs back in, & give it a try.
D

[/ QUOTE ]

Don't forget to pull a coil primary (small wire) lead before cranking to prevent lots of sparks flying around as fuel vapor squirts out of the plug holes.

 

[John75]

If you need an extra set of hands /ubbthreads/images/graemlins/hammer.gif or eyes drop me an email. I'm also a newbie to this group and we live in the same town /ubbthreads/images/graemlins/savewave.gif(Olathe). I've got the Haynes Carb book if you need to borrow it.

John
75 Spitfire

 

[CaptDon01]

Thanks to all you guys for the advice. I used oil I got from Victoria British for the SU carb's. I'll try the cleaning solution and see how it goes. John, I live between Mur-Len and Blackbob on 124th Circle. Are you a member of the KC Triumph club? Are you going to the "All British Car and Cycle Show" at the airport over the Labor Day weekend?

Thanks again to all for the advice!

Don

 

[John75]

I just picked up my Spitfire a couple of weeks ago and made contact with the local club a couple of days ago. I also had some carb problems that this group helped me with. My son and I are going Saturday during the day to the "All British Car and Cycle Show." I live on Sleepy Hollow Circle (love that name around Halloween time), between Ridgview and Mur-Len. Send me an email off list.

John
75 Spitfire

 

[vettedog72]

If the SU's dash pot is simular to the ZS's, then my $0.02 bet is that you lost the spark some how. Not much will keep the starter fluid from igniting except no spark. Whenever I have over filled my ZS's they just shoot the excess out of the small breather holes on top of the carb, close to the dash filler protrusion when under full acceleration. The over fill never seems to interfere with starting; but then, that ZS's.

 

[Simon TR4a]

I don't think the level of oil in the dashpots is too critical; a well-known builder of Mini engines in Britain, Bill Richards, advocates filling them and letting the excess drip out.
I have noticed different throttle response and popping from the exhaust on the overun when the oil is low, but neither c ondition should prevent the engine from starting.
Simon.

 

[Geo Hahn]

Good morning Capt! I too first suspect ignition when I get no firing at all. Likely culprits include:

Broken wire connecting the coil & dizzy, possibly white w/ black stripe. Can break inside where you can't see it. Any old wire will do in it's place for now.

Broken little black wire inside the distributor, this is a special flex wire and if broken should be replaced with same.

Points gap lost... can happen, esp if the car has sat awhile and the points were not tightened down well.

Failed component -- coils and condensors can fail totally and w/o warning.

I like one of these for checking to see if I have spark though the usual way with a screwdriver etc works and can be exciting too:

https://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=4424

BTW I have often over-filled the dashpots -- just consider that an upper cylinder lube. Never caused a problem though low oil will surely give me a miss under acceleration.

 

[Cain]

The local LBC mechanic told me that if you overfill the dashpots then the worst thing that can happen is you will have to clean the oil off the floor.

 

[CaptDon01]

Well, I sucked some of the oil out of the dash-pot and pulled the plugs. I turned the engine over and checked the spark-plug gap for the heck of while they were out. I put everything back together, and started her. She started to hit and finally started up and ran great, (well, like she normally does anyway). I believe I had badly flooded the engine while trying to get it going. My carbs arn't adjusted the best, and I've been running VERY rich. I leaned the carbs a bit and test drove it. I came back and pulled the plugs to check their color. 1 & 2 were still indicating rich, and 3 & 4 were ever so slightly rich. I adjusted them again, and after a nice run, 1 & 2 were just slightly rich, and 3 & 4 were perfect,( the plug was a light brown color). After another adjustment to the front carb, all the plugs were a nice light brown/tan color after a 40 mile test drive. The car ran GREAT too....and it's never idled so nicely either.

By George I think I got it!!!

Thanks to all.....

Don

 

[Adrio]

Good for you. I wish I could get my plugs light brown/tan. I only seem to manage black, even when all the other signs point to the correct mixture.

 

[Geo Hahn]

Plug color can be affected by gas formulation. Summer-recipe, non-California gas is about as good as it gets down here. Not sure what formulation is used north of the border.