#
It is currently Mon Sep 01, 2014 1:31 am


Post a new topicPost a reply Page 1 of 1   [ 8 posts ]
Author Message
 Post subject: hitachi su carbs(spl311)
PostPosted: Mon Oct 11, 2010 7:59 am 
User avatar

Joined: Tue Apr 20, 2010 1:07 am
Posts: 135
Location: philippines
what seems to be the problem on this, the engine idles good and revs smoothly but is having a flat spot around 3800 to 4000 rpm and it can't rev further than that, it already got new fuel filters, fuel hose and a cleaned up tank and lines, any help and input would be appreciated :)


Top
 Profile  
 
 Post subject:
PostPosted: Tue Oct 12, 2010 6:49 pm 
User avatar

Joined: Sat Feb 10, 2007 5:23 pm
Posts: 297
Location: Napa Ca
Check to make sure your distributor is pulling full advance, I bet its not. If it is, you might be going a little lean on the mixture, fatten the mixture up by turning the fuel adjustment on the underside of each carb.

You want to be at 16 degrees at 750 rpm, 36 degrees 4500.

Will

_________________
1969 Datsun 2000 (track car, driven daily)
1959 Alfa Romeo 101.02 Sprint (big project)
1969 Alfa Romeo 105.51 GTV (R.I.P)
'87 BMW M3


Top
 Profile  
 
 Post subject: Vacuum Advance
PostPosted: Fri Oct 15, 2010 9:21 am 

Joined: Tue Dec 25, 2007 11:44 am
Posts: 157
Location: Rancho Palos Verdes CA
The roadster used two different methods of hooking up vacuum advance to the distributor. First one was a simple striaght tube system joined to the rear SU with a simple vacuum hose jumper. The later system used a flared attachment with the nut on the vacuum line. If you have the early version, check to make sure that your vacuum hose hasn't dried out of indeed may be missing. Flair? Check that it is still connected.

_________________
MikeRL411


Top
 Profile  
 
 Post subject:
PostPosted: Fri Oct 15, 2010 9:57 am 
User avatar

Joined: Tue Apr 20, 2010 1:07 am
Posts: 135
Location: philippines
thanks for the replies, i've checked the timing advance and the vacuum lines and its all good, i did fatten the mixture and it slightly got better but it still eventually getting a flat spot, i think its having some fuel shortage or something


Top
 Profile  
 
 Post subject:
PostPosted: Wed Oct 20, 2010 12:42 pm 
User avatar

Joined: Wed Oct 20, 2010 11:28 am
Posts: 41
Location: Neuchâtel Switzerland
I seem to have a similar problem with my engine. The next things to check for me will be the needle valve in the float chamber and whether there are air leakage at the carbs at high rpm. I hope it could help you.

_________________
1973 euro 240Z


Top
 Profile  
 
 Post subject:
PostPosted: Wed Oct 20, 2010 12:43 pm 
User avatar

Joined: Wed Oct 20, 2010 11:28 am
Posts: 41
Location: Neuchâtel Switzerland
I talk about the needle valve because of the important notice written in this webpage: http://www.teglerizer.com/sucarbs/techtip6.htm

_________________
1973 euro 240Z


Top
 Profile  
 
 Post subject:
PostPosted: Thu Oct 21, 2010 8:22 am 
User avatar

Joined: Tue Apr 20, 2010 1:07 am
Posts: 135
Location: philippines
mitx wrote:
I talk about the needle valve because of the important notice written in this webpage: http://www.teglerizer.com/sucarbs/techtip6.htm


thanks for the link :)


Top
 Profile  
 
 Post subject:
PostPosted: Sat Oct 30, 2010 11:58 am 

Joined: Thu Feb 08, 2007 7:40 pm
Posts: 74
Location: Maryland
take off the air cleaner and rev it up to the flat spot. Place your hand in front of the carb (blocking that air) and see if it goes higher. If so, your needle is bent.

_________________
Mark
Maryland


Top
 Profile  
 
Display posts from previous:  Sort by  
Post a new topicPost a reply Page 1 of 1   [ 8 posts ]


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 © 2000, 2002, 2005, 2007 phpBB Group
610nm Style by Daniel St. Jules of Gamexe.net