engine won't start

[Marine]

i am open to any suggestions. i have set points, cleaned carbs, i amgetting fire at the sparkplugs, i have plenty of fuel, but engine just turns and turns over. i rode the bike for about 1 hour , came home and parked it next day nada NOTHING WILL NOT START. battery is ok plugs are fairly new tire are still round, whats going on please help. obtw the mischevious bike is a 1977 r75/7. thanks

[From MARS]

Fire; check. Fuel; check. Compression;? Pull the plugs and stick your finger over the hole if you don't have a compression gauge.

Tom

[coon]

I’ve used the basic info given to me by a tech at Pratt & Whitney several times.
All internal combustion engines have to do four things.
Suck, Squeeze, Bang and Blow.
My Last experience was it wasn’t Banging even though I thought I had set the points right, I hadn’t.
Drop back and look at each.
Good Luck.

Dave.

[Bill Burke]

The starter relay is under the tank, on the main frame spine, left side forward. Remove the starter relay and re-insert. Do it once again. And once again.
Now try to start it. Corrosion on the red wires at the starter relay can cause the problem you're having. This suggestion is based upon a known good battery, and no failure of the battery cables.

[20774]

I'd recheck the static timing to make sure it's firing when it should. You said you're getting spark and have fuel...maybe the firing is not at the right point.

You cleaned carbs...is there fuel in the float bowl? Petcocks on...choke on?

Kill switch?

Be sure all the simple stuff is correct.

[edwarddieck]

Getting spark so I assume the engine turns over. Change the condensor. Even though you are getting spark it may not be enough when under pressure.
That took me 3 months to figure out.
Ed

[Guenther]

"...new tire are still round"

Ah, that's it...they should be square!

Now a little bit more of the story might help. Did you do all the checks/changes after you rode her for an hour or before?

Since you seem to get a spark and fuel it should make a fart of some sort. I can only add another blind suggestion: check the valve clearance.

/Guenther

[AnnapolisAirhead]

IF you are confident that the timing is set properly, have you set the valves? They should be set with a stone cold engine.

[jamesdunn]

i am open to any suggestions. i have set points, cleaned carbs, i amgetting fire at the sparkplugs, i have plenty of fuel, but engine just turns and turns over. i rode the bike for about 1 hour , came home and parked it next day nada NOTHING WILL NOT START. battery is ok plugs are fairly new tire are still round, whats going on please help. obtw the mischevious bike is a 1977 r75/7. thanks

Was it running before you did the above? It makes sense to check your most recent work. As others have said; points set right, timing? Have you set the valves recently? If it is a condensor a substitution is best way to check (Are points blackened?).

[pmdave]

You didn't happen to "gas up" with diesel during the last ride, did you?

pmdave