Ptero Posted June 26, 2021 Share Posted June 26, 2021 (edited) Found the engine to be stumbling a bit so I'm trying to dig into what the issue is. L28 with an E88 head. Pulled each sparkplug wire individually with the car running and there was no change when I pulled the wire leading to cylinder 3. Placed the wire close to the sparkplug and I could hear it sparking so I know it's hot. Got a new set of spark plugs, no change. Tried another wire, no change. Cleaned cap & rotor, no change. Adjusted all valves cold to .008 for intake and .01 for exhaust, no change other than running smoother overall. I didn't adjust them when the engine was hot. Next I did a compression test with the following results: 1 - 133 dry / 141 wet 2 - 135 dry / 140 wet 3 - 135 dry / 142 wet 4 - 136 dry / 143 wet 5 - 140 dry / 148 wet 6 - 144 dry / 153 wet According to my spark plugs (which are black & sooty), I believe I'm running rich. Carb setup is round top SU carbs which I tuned last summer. I barely drove it last summer, but I'm thinking it was stumbling then as well. While I search for the next step, I'm also looking for suggestions on what to try next. Edited June 26, 2021 by Ptero Quote Link to comment Share on other sites More sharing options...
rossman Posted June 27, 2021 Share Posted June 27, 2021 What you mean by stumbling? Does it idle smoothly? Quote Link to comment Share on other sites More sharing options...
bunkhouse Posted June 27, 2021 Share Posted June 27, 2021 The next thing I'd check is the float levels. The fuel level should be 3/8" below the carb bridge. That's 9.52 mms. The nozzle adjustment screw raises or lowers the nozzle 1 mm per turn. Remove the domes and pistons, raise the nozzles up to the top and lower them 9 1/2 turns. The proper fuel level should be at the top of the nozzle give or take a half a turn. Quote Link to comment Share on other sites More sharing options...
Ptero Posted June 27, 2021 Author Share Posted June 27, 2021 17 hours ago, rossman said: What you mean by stumbling? Does it idle smoothly? Cold start: Operating temp: Quote Link to comment Share on other sites More sharing options...
Ptero Posted June 27, 2021 Author Share Posted June 27, 2021 Noticing a fair amount of smoke from the exhaust on that 2nd video 😬 Quote Link to comment Share on other sites More sharing options...
rossman Posted June 29, 2021 Share Posted June 29, 2021 Seems to me that it's probably running way too rich. Have you tried leaning out the carbs? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.