July 21, 201214 yr comment_616868 Hey guys I've just out a 5k in my 26 that has had a little amount of work done to it at some point, put new carbies on there and got it running. Only problem is that cylinder 1 doesnt do anything! So far I've figured out that compression is good, I've got spark (at the plug), valve springs and push rods are fine and I have fuel as its on the plug when I pull it out. As I'm a novice mechanically what else could I be looking at? I'm assuming a valve problem? Edited July 21, 201214 yr by RA28GT Report
July 21, 201214 yr Author comment_616926 Ok making progress with this its almost defiantly a fuel/carby issue. First cylinder kicks in at approx 2000-2500rpm under load, so I'm thinking its blocked, or its just ramming in too much fuel possibly. Report
July 21, 201214 yr comment_616944 Ok making progress with this its almost defiantly a fuel/carby issue. Only if it is a leak into the manifold at #1, otherwise surely a fuel issue would affect all 4 cyls. If its twin carb then it would affect 1 & 2 cyls the same. Do what Trev says to start with and see if the misfire follows the plug or lead. The compression test should show up any valve problem, so there is not much else that can be causing it. What were the compression readings? Report
July 21, 201214 yr Author comment_616946 Tried swapping the plug and lead? Yep lead and plug makes no change, both cylinder 1 and 2 are very weak at idle, no change in 1 with the lead removed and a tiny change in cylinder 2 with the lead removed. Its twin Dellortos so I'm thinking an issue with the front carby. They were rebuilt 6 months ago and have sat until this time, so never been run. Report
July 21, 201214 yr comment_616953 pull the plug off while running and hold it to the head and see if your getting spark Report
July 21, 201214 yr Author comment_616963 pull the plug off while running and hold it to the head and see if your getting spark Defiantly spark. Was one of the first things I done. Report
July 22, 201214 yr comment_617005 Sounds like carb as you say. I think its Dellorto's that have the chokes come loose in the body, so check that and then it will have to be a strip to check float level and dried out resin or dirt on the needle and seat.. Report
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now