'88 Paso 750 starts on one cylinder only. Spark good.
Posted: Tue Aug 29, 2023 6:29 pm
I have a 1988 Paso 750 that was a non-runner. I am attempting to resurrect it from the desert where is sat outside with a tarp cover. After a few months work and recovery I got the bike to run. However, I found it only starts on one cylinder (vert). The horizontal does not fire.
The spark is the first thing I checked - good there. The compression is the same in both cylinders. The fuel delivery is good.
I now have a small tank set up on the bars and fuel runs directly into the Weber carb. The Weber is a 44 DCNF 107 that has been rebuilt by me. I thought I did everything right, and am now checking things again. On the first rebuild I ran air through all the vents and made sure the jets were clean.
If I squirt some starting fluid down the intake, the bike fires like a demon. It will not draw fuel from the regular feed into the one intake. No air leaks that I can find, and like I said - it does fire on fluid.
Looking at the carb the second time, the only odd thing is that the float level was very high - doesn't look like the way I re-assembled it.
Also the four hole gasket on the carb base was wet in the rear where is covers the two slanting grooves.
Before I get flamed by all the experts out there - I HAVE looked all through this forum and found some good articles on jetting and total carb operation (from the "show pictures of your Weber" posting). But I still am lost on why one intake does not work. The jetting I can look into after the bike starts and runs.
I am probably missing something very simple and just need a nudge in the right direction.
Thanks to all. I've enjoyed this forum for many years, and received some good advice on my first 750 Paso long ago; it was my first Ducati and got me started on ownership of various Ducatis over a long period.
The spark is the first thing I checked - good there. The compression is the same in both cylinders. The fuel delivery is good.
I now have a small tank set up on the bars and fuel runs directly into the Weber carb. The Weber is a 44 DCNF 107 that has been rebuilt by me. I thought I did everything right, and am now checking things again. On the first rebuild I ran air through all the vents and made sure the jets were clean.
If I squirt some starting fluid down the intake, the bike fires like a demon. It will not draw fuel from the regular feed into the one intake. No air leaks that I can find, and like I said - it does fire on fluid.
Looking at the carb the second time, the only odd thing is that the float level was very high - doesn't look like the way I re-assembled it.
Also the four hole gasket on the carb base was wet in the rear where is covers the two slanting grooves.
Before I get flamed by all the experts out there - I HAVE looked all through this forum and found some good articles on jetting and total carb operation (from the "show pictures of your Weber" posting). But I still am lost on why one intake does not work. The jetting I can look into after the bike starts and runs.
I am probably missing something very simple and just need a nudge in the right direction.
Thanks to all. I've enjoyed this forum for many years, and received some good advice on my first 750 Paso long ago; it was my first Ducati and got me started on ownership of various Ducatis over a long period.