I've got a build thread running on there...There are guys on 2strokeworld.net with 2T for blood. They would be who I would go to for 2 stroke tech assist.
Interesting, thank you. We're still scratching our heads here. More anon.My '76 RD400c had 110 both sides. Both before and after crank rebuild/resealing.
Thanx Teazer, I tried another test wet and the psi raised to 40psi, so the gauge is not peaking out at 35 but still not entirely trusting the calibration/operation.I used to have 165psi on a GT750 and dropped that down to 155 after raising the exhaust port a little more.
30 PSI is not a real number... Try a different gauge and/ or try it again without pipes or carbs just to be sure one or other isn't blocked. Ebay cheap compression testers often show that sort of number. I threw one out and so did my neighbor. Different ebay sellers but the same crap dressed up to look like a decent tester.
I'm not relying on the gauge, following many replies and stated figures. However, a dirty CDi loom was spotted and it fired up after 2-3 stabs on the starter. How it runs on the road is another matter, but it runs for now,The lowest compression I've seen factory spec was on my 1984 JS550 twin Kawasaki Jet Ski. 115+/- 10 psi.
It ran pretty good with 105psi and 87 octane.
You have BAD compression.
If I saw 95psi, I'd probably try to get it started by turning it over quickly and seeing if it' would take. Otherwise, freshen her up and get it into the low-to-mid 100's.
maybe, I missed off 100 psiI have 135 on my decked RD350
Well, your bad contact suggestion turned out to be the cause. The threeway from gen to CDi unit was dirty and loose....I had only thrown it together to see if it ran. All cleaned up and tightenedThats a bit of a bugger Colin....especially as you're so close to done!
Bear in mind it was half a lifetime ago that I last worked on a 2 stroke but I'd have thought it unlikely the seal would just go abruptly....more likely there'd have been symptoms before....hard to start/poor idle?
I did at one time build Suzuki 250 single race bike engines and we used to pressure test the crankcase to check seal condition.....by blanking off inlet and exhaust ports and pumping some air in through the plug hole.....only a few psi though!
Other thought is something I used to come across a lot on smallish bikes.....though uncertain if it applies to yours or not.....though they seemed to spark ok at the plug I found that dirt/damp etc on the contacts on the back of the ignition switch (or sometimes kill switch) caused tracking problems (sometimes you could actually see a mark joining the terminals) and once the plug was back in the engine the spark must have been very weak.....
Maybe worth a look?