Well, to put it in real terms, attempting to do stuff differently to prolong the life of a low compression rotary is like trying to do stuff differently to prolong the life of brake pads that are nearly to the backing. Not using them is the only way to delay the inevitable.

In both cases, it is quite literally that material is missing, and nothing you can do will put that material back without actually replacing parts.

An upgraded/new starter will help mask the hot start problem, but not for long.

 

So those numbers do indicate low compression, and I'm SOL?

 

Those numbers indicate 'A' compression. Without the RPM, we don't know if they are low or not. If your starter speed was 200rpm, those are actually pretty good! If your starter speed is 300rpm, then your engine is FAR below spec.

Yes, the RPM is that critical to knowing what the numbers mean.

We can hope or assume that they are normalized to 250rpm, in which case you are right on the edge before failing, but again, it's just a guess.

 

Initial numbers should have read 250 rpms for test

 

You previously mentioned that he said "750rpm", so the RPM is still a question in our mind.

It's rare that a compression test is actually performed at 250rpm, as every starter is different. There is a normalization calculator (Foxed.ca - Rotary Compression Calculator) that the dealer's use to normalize to 250rpm. Not every dealer does this, some just give you the numbers as they are.

 

Here's a picture of rotor 2 test compression on my 2004...

Mazda Canada changed the motor last june with 64500km original kms (40k miles) on my 8!

I don't think your motor's that bad!...
I'd try to remove the injectors and having them cleaned first?

 

^ again, as I noted, it all depends on his RPM. Your numbers ARE indeed terrible at 275rpm

 

There you go.

 

He came back and said 750 was a typo. It was tested at 250. I've got them testing the starter now.

 

Most recent email
The no part number concerns me a bit.

 

Just take the car back and buy the starter yourself. Every time you post a communication from that dealer I am less and less impressed. Well, I was never impressed to begin with so perhaps it's more accurate to say I'm more and more disgusted.

You can buy a new starter for about $380 from Mazmart and they will be sure to get you the right one. Replacing it is 1 clip, 1 12mm bolt for the power cable, and 2 14mm bolts holding it to the housing. There is nothing blocking it, can access it easily. No point in paying these guys a dime more.

 

there is a sticker on the starter with a part number, but i think it faces up, its not legible with the thing in the car. installed the new updated starter looks like the old one, so its not like an obvious difference

the starting and charging system might be fine, but Mazda does have an updated faster starter, and the fact that they don't seem to be interested in looking for that bulletin (and selling you one!) is a bit disappointing.

 

If your starter is putting out 240+ I dont see a need for a new starter... the ONLY way you will know if it needs a starter or engine is by them supplying proper RPM numbers or retesting with RPM numbers.

Been a early model, have you never had the starter replacement?

 

I just put in a new starter yesterday (and busted my head on the underside of the car trying to get that stubborn bolt to come loose). And I'm in like flynn. Started up smoother than it had in years... wait, that's a lie. I definitely had a misfire and it wasn't happy on the FIRST startup with it. Which scared me a little, but the starts following it were just fine. So I guess my quote has changed, I'm either going to drive it until the wheels fall off, OR the engine drops out... whichever happens first.

 

I just went thru the same thing and my starter was a month old Denso unit. I slapped my buddies R3 starter (upgraded and different design) on and it starts like a champ. This is why I keep preaching a proper diagnosis. People automatically assume hard hot starts are low compression and that is just not true. Glad you got it sorted.

 

New starter from autozone for 100 bucks ( 07' rx8 6 mt starter ) solved all my issues, no more hard starts when warm and starts up faster then ever before better than new

 

Cant wait for my starter to get here....

 

you never replaced the battery.

Simple test. Take any battery out of a car. Put it in and see what happens.

Also, are you sure the plugs are put in the correctly. There are two different types.