HI all..I hope you are well after covid and still having fun in your rotary engined cars..
I've had a lot of fun in mine..
I've had 3 of these cars and rebuilt a few engines..
I used to be a mechanic but I'm a pen pusher full time now.
I've had my Current rotary engine rebuilt professionally..
and I've ironed out a lot of issues..
Its a Full de cat and goes like stink.
it only gets driven monthly...
It was off the road for two months during covid..
It has developed a strange problem..and I think I know what's going on but I would like some feedback from the knoweldge base here before I attack the problem..
I am well aware of how the hot start issues manifest..
Housing expands when hot...tips don't reach...when worn no compression etc
my issue is thus..
I start the car when cold...perfect...
Runs until hot...
Turns off...won't start again until it cools..
Then after that..in that day...it will start all day when hot ..
No matter how much I heat the engine up..
It starts very very well...within a second or two..
its just that iinitial cool down hot start causes an issue.
the engine spins with.no compression..
then after that..its fine...
The car lies up a lot..
4000 miles since rebuild...regular oil changes ..
I add 2 stroke..
Mineral oil only..
My feeling is that the rotor tips are sticking in a retracted position..possibly from deposits from the two stroke oil..
because of lack of use..
once its heated and cooled again the tips unstick themselves..
I've already replaced the ssv trigger solenoid..
(White one).
Installed an oil catch can ...
and an improved radiator...
The engine is very healthy...
Just this one strange problem..
As I said once itts heated and cooled once its fine..
but its annoying..
ive scrolled through the forums and ive seen people remove the manifold...and then work the rotor tips back and forward with some sort of degrease or decarbon spray...
maybe carb cleaner...
Might be harsh on the viton seals tho..
im lookng to narrow this down for unnecessary part removal..if I can avoid removing the manifold would be great..as it's an absolute pig to remove..very little clearance..
(I've had it off for various jobs)
Thanks everyone..
Happy sideways motoring

 

Just to point out, you've put "engine is very healthy" and "spins without compression" in the same post. I don't think the theory about apex seals remaining retracted makes a ton of sense, but let's do this by the book.

- what are the actual compression numbers?
- when it's in the no-start situation, is the engine itself turning, or is only the starter? There's a mode of failure where the starter doesn't engage the flywheel.
- the correct 2-stroke shouldn't leave deposits, that's the whole point of running it, but which 2-stroke are you using? most deposits you find in any engine are from fuel.
- there are many ways to decarb that don't require removing the manifold. water or Seafoam are a start, but nothing beats and old fashioned italian tuneup.
- can you pull the spark plugs and check for signs of coolant, excess oil or fuel?

 

It's blowed up mane.

 

The starter motor engages with the flywheel
the compression numbers are healthy after one heat and cool cycle..
theres no coolant leaks... ...this isn't ny first rodeo..
Ive done all those tests I thought I made that clear .
the engine has been rebuilt 4000kms ago...and has been lying up periodically for long periods...
as usual posts on this site are full of negativity...
I've never had any useful advice from this site about rotary engines....every fault i fixed was through a process of eliminatation...and was never...
complete seal failure...which is what I'm told every time I post here..
I bought 2 cars with a worn rotary engines. .I rebuilt one engine...and had the 2nd rebuilt...so I know the symptoms of a worn engine..
continual hot start issues which is what mine is not
last time i posted here i was told i had a blown engine ..
it turned out it was sucking oil residue in from the oil filler
as there is constant vacuum..
The time before that i posted I was told.ihad a blown engine...
When what was wrong was the bearings in the omp pump position motor had seized...
I then completely stripped the omp pump posituon motor and replaced the bearings.quite.cheaply...
so no ....my engine isn't blown this time..it wasn't blown last time and it wasn't blown the timw before that...
thanks for less than helpful input guys...
waste of time as usual...

 

Well it sounds like you have all the answers then, good luck.
If you do decide you need input, answer the questions asked. We're not mind readers or magicians.

 

I've taken it out 3 days in a row ...
revved the nuts of it and its starting perfectly...
something is sticking after it's been left lying up