Low Comp. Readings

[RagTop69GS]

Here's what I have, 69' GS 400 stock engine with 68,000 miles. freshly rebuilt carb, dwell & timing set to Fact. specs and I get low Vacuum reading .
When I advance the timing to I'm guessing 15-20 deg. I get 16" of vac but hard starting and spark knock. I can find no Vac. leaks anywhere. Vac. guage was slightly jittery. I did a compression check and here's what I found.


DRY DRY wet
150 150
145 125 155
140 130 170
180 155
F

I only wet checked the two lowest cyl. which happen to be next to each other. I know this indicates poor ring seal. Is there anything I can do to make this last the season before I do a rebuild in the fall ?

The car idles great, no smoke but has no power. When I step on it it dosen't bog but seem to lack any power.

Any ideas on whats up with this engine. It ran good last season except for stalling when I stopped after about 2 or more hours of driving. Didn't stall till it was good and hot.




Thanks Jay :confused:

[cray1801]

Jay, I'd suggest a leakdown test, this will help get the whole story without as much speculation.

[RagTop69GS]

Thanks Craig, :TU:

I'll be doing that this weekend. I'll post what I find.