Won't run after baseline carb adjustment

Started by amanley, March 22, 2019, 10:18:19 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

amanley

I have an HS4 that was running rough (and I never could start it without using starter fluid) so I've recently replaced a number of components (gaskets, choke springs, conversion from waxstat jet to normal jet, new jet adjuster, red piston spring, fresh dashpot oil) and it will run on starter fluid but once it's run out it dies. I ordered a new needle (it was showing signs of wear but wasn't bent) but have not yet replaced the needle.

I have fresh fuel that is getting to the jet. Fuel pot is clean but I didn't replace the fuel float or fuel needle as those looked ok. However the float is completely plastic and rests at about 3/16" from the lid when full instead of 1/8". Since I couldn't adjust this I left it. But I'm wondering if the float is keeping the fuel too low for where the jet is set.

After a bunch of no starts I went through the process of adjusting the carb to baseline to get it ready for tune (adjusted jet nut two full rotations down from flush with bridge and idle setting to 1.5 turns).

I've checked the spark too. All plugs are new, gapped, and are sparking under crank. The contact point is correctly gapped as well. I have not however adjusted the timing since I haven't gotten it to run steady. Battery is new as well.

I think it's a fuel issue but I thought I'd see what you all recommend. Should I continue lowering the jet until I can get it to run steady? I also wonder if bad timing had something to do with it. Unfortunately my choke cable seems to be bound shut but the above had all been done with choke fully disengaged. Sorry for the long post and thanks in advance for the help.
1978 BL mini 1000
2005 MINI Cooper S JCW
2013 MINI Countryman All4

MiniDave

#1
Try something, the big breather hose that's connected near the dome, take it off and block that pipe on the carb and see what it does. I had the same symptoms on my test engine stand, plugging that pipe it ran perfectly!

Also make sure the piston can move up smoothly in the dome.

Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

94touring

Manually engage the choke after you've gotten it to run on starter fluid and see if that keeps it going.

amanley

I've been trying to just get it idling for a tune so I haven't run the air filter or vacuum lines but I'll try blocking the breather hose and see what that does. thanks

I guess I need to take out the choke cable anyway to see why it's stuck. Might as well do that and clean it up and see if I can give it more choke once I get it going.
1978 BL mini 1000
2005 MINI Cooper S JCW
2013 MINI Countryman All4

amanley

Update - I got it going after a few tries with starter and then pulling the jet down. I was able to hold the jet down and keep it running but as soon as I let it up it would die. This was the case with the vent plugged or open. So right or wrong I lowered the jet a couple of full turns until I was able to get it running without holding the jet down. I then played with the idle adjustment and raised the jet back up until I got something I liked. I still need to do a legit tune but I feel much more comfortable about it now. Unless you have other thoughts I'm guessing it just needed to be enriched a little and warned up some to get it to idle. Still doesn't want to stay without starter fluid so I have some more work to do.

Thanks for the help. I'm open to suggestions as well as I'm still learning. Thanks
1978 BL mini 1000
2005 MINI Cooper S JCW
2013 MINI Countryman All4

94touring

Once you get it running well enough to move it on the road, bring it to the shop and I'll help fine tune.

amanley

That would be awesome! Thank you. My goal is to get it on the road before the cook out so I can come out then.
1978 BL mini 1000
2005 MINI Cooper S JCW
2013 MINI Countryman All4

amanley

Somewhat successful today. Got it warmed up with the choke and was able to keep it running with no choke once it was warmed up. Set the idle by ear to maybe 900-1000? and then backed out the jet one flat at a time and subsequently raised the piston with the spring pin until I got close to a steady idle with piston raised slightly. It turned out to be something just over two full revolutions of the jet adjustment nut but the exhaust smelled and sounded a little too rich so I turned the jet up a couple of flats which seemed to be better.

Once it was warmed up I checked the timing and it was extremely retarded! No joke maybe 25 degrees?! I couldn't even see the timing marks in the inspection window! So i took the valve cover off, the spark plugs out, and the distributor cap off and rotated to TDC just to verify what I was seeing and that everything matched up. It all looked ok so I went back to the timing and started advancing the time while also keeping an eye on my idle adjustment. I now have what I feel to be around 900 rpm and 10 degrees btdc at idle.

Currently I'm installing a tach as I wasn't sure how I could set the all-in timing without a tach. That's about as far as I got today but should be able to adjust the all-in timing once the tach is in place.

I'm surprised the timing was that far off!
1978 BL mini 1000
2005 MINI Cooper S JCW
2013 MINI Countryman All4

amanley

#8
So I got the tach installed and working and went to finish my timing adjustment as I started to see light wisps of smoke and the smell of something burning!

So I started looking around and turns out the exhaust downpipe is just about resting on the pot joint boot! I really am not sure how this hasn't come up during the last two gallons of test fuel and tinkering. I don't know how close these are supposed to be and I'm not sure what exhaust / downpipe is installed but somethings got to be off. I'm guessing the exhaust is misplaced somehow.

I obviously won't be running it until this little setback is fixed and I'd love to try and bring it to the cookout in a few weeks. So I'd love any insight you guys have. Google search isn't helping much on how it should look and clearance between the two.

There's a lot of oil there too but i hear that's normal... Let me know if you want this posted in a new post.
1978 BL mini 1000
2005 MINI Cooper S JCW
2013 MINI Countryman All4

MiniDave

#9
I see you have plenty of "English rustproofing" - aka leaking oil under the car!

Yeah, you need one of those Center long branch exhausts that only have one pipe at that point.....

http://www.minispares.com/product/Classic/Exhaust_and_manifold/Exhaust/Exhaust/C-STR816.aspx?110201&ReturnUrl=/search/classic/lcb%20exhaust.aspx|Back%20to%20search
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

94touring

I have one barely used you can have for $50. Needs the next exhaust section cut off as it's on mega tight and I couldn't seperate them.  Better suited for a 998 and not rough looking like what you have.  So long as what you have isn't touching or rubbing, you're ok to get around.

amanley

Thanks guys, I think I will loosen things up and try to finagle some more clearance here first. Then wrap up the timing and carb adjustment. Thanks for the help!  4.gif
1978 BL mini 1000
2005 MINI Cooper S JCW
2013 MINI Countryman All4