It is currently Sun May 03, 2026 6:07 pm

Board index » Tech and Fab » Air Cooled Engines

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 36 posts ]  Go to page Previous  1, 2
Author Message
 Post subject: Re: Delorto 40's
PostPosted: Sun Jan 23, 2011 1:12 pm 
Offline

Joined: Fri Nov 23, 2007 11:27 pm
Posts: 496
Location: Chandler Az
Sound like the check valve/ball may not be seated. I'll trade flats of of Bud for them.


Top
 Profile  
 
 Post subject: Re: Delorto 40's
PostPosted: Mon Feb 07, 2011 2:00 pm 
Offline

Joined: Tue Mar 25, 2008 12:08 am
Posts: 234
Location: Ladysmith B.C. Canada
I've cleaned out all curcuits many times now, using spray gun cleanning brushes, solvent and air. I'll try again.
I guess next step is a compression test and re torquing the heads.


Top
 Profile  
 
 Post subject: Re: Delorto 40's
PostPosted: Sun Mar 13, 2011 4:02 pm 
Offline

Joined: Tue Mar 25, 2008 12:08 am
Posts: 234
Location: Ladysmith B.C. Canada
Up date and new questions. Turns out that the fuel was coming from the progression port not the accelerator pump jet. I was given a phone # of some one in California, who was able to tell me straight up that an internal plug was at fault. Followed his instructions and found plug was missing. Guess I left the carbs soaking in cleaner to long :( The other carb was almost the same. Drilled out the plug and the internal one fell out behind it. It now runs on all 4 at idle. Even heat on the pipes. But I may have left some crap behind or have vaccum leaks as it pops at idle. These have been on, off and apart so many times now I could build them in my sleep.

New questions, I don't like the hard phenolic heat pads and the rolling paper thin gaskets. I'd like to use the neopreme anti vibration ones that came with the carbs. However they have distorted, dried out and kind of shrunk. They are n't cracked and are still flexable. Is there some thing they could be soaked in to renew them?

Next, the spring loaded needle valves. Should they be set so spring/pin is compressed when floats are set level? The electric fuel pump, even at only 3 PSI pushes past the needle valves other wise. Thanks in advance, Dave.


Top
 Profile  
 
 Post subject: Re: Delorto 40's
PostPosted: Sun May 15, 2011 2:56 am 
Offline

Joined: Tue Mar 25, 2008 12:08 am
Posts: 234
Location: Ladysmith B.C. Canada
Multiude of issues seem to be behind me now. Between over oiling the filters, ( damd K&N knock offs) and what ever, the things seem to work pretty well. Hav n't been able to really get out and giver, but I 'm getting some popping when decelerating at about 2,000 RPM. Idle mix screws don't do much and am thinking that it's idleing through the low progession ports with the way they are set. Could the idle jets be to small,
( considering that the jets are stock for a 1600cc. I've got a 2276cc.) First guess would be pluged jets, but I've cleaned them out so many times there could n't possibly be anything in there. I do have a good selection of micro bits and could drill em. Any thoughts? Thanks. Dave.


Top
 Profile  
 
 Post subject: Re: Delorto 40's
PostPosted: Sun May 22, 2011 10:06 pm 
Offline
User avatar

Joined: Sun May 20, 2007 2:27 pm
Posts: 66
Location: Wayne, WV
If you have to loosen the idle mixture screws more than four or five full turns then you need bigger idle jets. drill them with micro bits one step at a time. 3 to 4 turns is about what you want. Those are the best carbs for a vw. You could have a bad float valve or need to set the float level. Float level is very important and tricky. If the float is to low the engine will stall after a high rpm decel. It will pop if to high. Also all of the dell rebuild kits that I get have the wrong needle valve and I get those seperate. If the valve does not seal good the engine gets flooded after shut off. Hope this helps........


Top
 Profile  
 
 Post subject: Re: Delorto 40's
PostPosted: Wed May 25, 2011 3:19 am 
Offline

Joined: Tue Mar 25, 2008 12:08 am
Posts: 234
Location: Ladysmith B.C. Canada
Seems that I've scored big then. However, they were rough, the shafts were rusted and the bearings siezed. All new now. Did a shake down run up the mountain the other night, ran great. Still want an expert to check and tune them, or advise what they need. This site is awsome, and thanks to all, as you've gotten me close but it will take hands on, (some one with one of those mercury ball set ups), to get it right on the money . I know of a guy who has the equipment and experience with side drafts. Problem is I can't afford him right now. I just got back to work after being off since late January. ( Hernia ) :(

The Dellorto manual suggests that the idle mix screws be out 2 1/2- 3 turns, un like Webbers which I think are 1- 1 1/2. I've only ever been a back yard mechanic, but sure have learned a lot from building this buggy.

May be this will help your diagnosis. It seems to take the engine quite a while to idle down. More than what I would like. I think I have the floats set some what tight, ( due to the spring loaded needle valves). Any other thoughts? Thanks.


Top
 Profile  
 
 Post subject: Re: Delorto 40's
PostPosted: Wed May 25, 2011 5:03 pm 
Offline
User avatar

Joined: Sun May 20, 2007 2:27 pm
Posts: 66
Location: Wayne, WV
I always use an extra spring.hooked where the cable connects to the the throttle body and where the cable housing connects. the carb spring is probably weak.


Top
 Profile  
 
 Post subject: Re: Delorto 40's
PostPosted: Thu Jun 02, 2011 2:05 am 
Offline

Joined: Tue Mar 25, 2008 12:08 am
Posts: 234
Location: Ladysmith B.C. Canada
I got a big ass spring on the peddle. I think I need to go to heavier springs in the distributor. It will run a fast idle 1,100 rpm for a couple of minutes then suddenly drop 3-400 rpm. So I think thats where the advance wieghts come in. Hav'nt had a chance to test that theory yet.
I actually raced the thing on the week end. Did pretty good, won my entry money back. Should get better with improved tuning and experience.


Top
 Profile  
 
 Post subject: Re: Delorto 40's
PostPosted: Thu Jun 02, 2011 5:39 pm 
Offline
User avatar

Joined: Sun May 20, 2007 2:27 pm
Posts: 66
Location: Wayne, WV
When it is at a fast idle try to manually push on the linkage so it will return to idle position. if the idle slows then you need a spring at the carb end.


Top
 Profile  
 
 Post subject: Re: Delorto 40's
PostPosted: Thu Jun 02, 2011 5:39 pm 
Offline
User avatar

Joined: Sun May 20, 2007 2:27 pm
Posts: 66
Location: Wayne, WV
When it is at a fast idle try to manually push on the linkage so it will return to idle position. if the idle slows then you need a spring at the carb end.


Top
 Profile  
 
 Post subject: Re: Delorto 40's
PostPosted: Fri Jun 03, 2011 1:47 am 
Offline

Joined: Tue Mar 25, 2008 12:08 am
Posts: 234
Location: Ladysmith B.C. Canada
Springs at both carbs.
Trying to post pic, but don't do it often enought to remember how, old timers desise. Can't spell either. Read the other guys post on timing or curving. I've updated where I'm at there.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 36 posts ]  Go to page Previous  1, 2

Board index » Tech and Fab » Air Cooled Engines

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group