Need your Help

unkleg · 09-11-2011, 06:58 PM

Hello all,

I need your help I have a Mazda 13b motor in a Manx. I think the motor is a 1985 but not sure is there any way of telling what year it is.

Now the reason I ask is, it's been running really poor and I thought it needed a tune up so I did that and still running bad so I asked on RX7 site and they said it's a carb. problem so I over hauled the carb. WELL GUESS what it still runs bad.

So I did a compression test and the front rotor has 0 yes zero pressure. So I think I need to rebuild it.

Any help would be great

Thanks in advance.
Greg

FerociousP · 09-11-2011, 07:22 PM

Post detailed pics and your question will be answered within a few hours!!

and if it did read zero you would definitely need a rebuild. What was the compression of the other rotor?

jfaplanet · 09-11-2011, 08:20 PM

Unkleg, what kinda help are you needing, if you do indeed have 0 compression on a rotor, then you do need a rebuild. If you motor is an 85 13b it is from a GSL-SE and the last year that they built that style of motor. There are options but we need to know what type of engine mounts you are using. Post up some pics and someone is sure to help.

Where are you located may be helpful also.

unkleg · 09-11-2011, 08:55 PM

Quote:

Originally Posted by jfaplanet

Unkleg, what kinda help are you needing, if you do indeed have 0 compression on a rotor, then you do need a rebuild. If you motor is an 85 13b it is from a GSL-SE and the last year that they built that style of motor. There are options but we need to know what type of engine mounts you are using. Post up some pics and someone is sure to help.

Where are you located may be helpful also.

The other Rotor had 65 psi on T and L. I live in Temecula Ca. between San Diego and Riverside.

Pics coming.

unkleg · 09-11-2011, 08:56 PM

This is what its in.

unkleg · 09-11-2011, 08:58 PM

Here is the motor. Hopefully these help its hard to get a good pic. there's not much room.

dream36realms · 09-11-2011, 09:49 PM

looks like the gsl-se oil pan on there Thats all I can add

FerociousP · 09-12-2011, 09:03 AM

I does look like a 13b from a 1st gen... I hope you were premixing... and that the timing is/was set right.

unkleg · 09-12-2011, 09:19 AM

Quote:

Originally Posted by FerociousP

I does look like a 13b from a 1st gen... I hope you were premixing... and that the timing is/was set right.

Premixing???? WHAT no one told me anything about having to premix. As far as timing I never touched it so I hope it was right also.

You are making me rethink this motor rebuild and going to a newer one instead.

FerociousP · 09-12-2011, 10:59 AM

Quote:

Originally Posted by unkleg

Premixing???? WHAT no one told me anything about having to premix. As far as timing I never touched it so I hope it was right also.

You are making me rethink this motor rebuild and going to a newer one instead.

The oil injection has been removed on that engine. Its common practice, especially in custom applications and when modifying/ changing carbs, etc. An arguably standard amount is 1 oz. per gallon of 2-stroke Tc-w3 added to the fuel. Your internal metal seals (apex, side, and corner seals) were not being lubricated (comparable to piston rings). Yo uprobably have quite a bit of internal wear and may be better off getting an entirely new motor. For simplicity sake I'd recommend staying with a GSL-SE block so you won't have any fitment issues.

unkleg · 09-12-2011, 11:41 AM

OK, so now after reading that I guess I am looking for a GSL-SE block if anyone knows where to go to get one.

Please let me know and this time I will make sure to add oil to the fuel.

I am looking in my area on Craiglist but found nothing so far.

I really want to thank you for all your help.

unkleg · 09-14-2011, 05:51 PM

I have another question.

Is this rotary a 6 port or a 4 port

730RWHP12A · 09-16-2011, 08:33 AM

Quote:

Originally Posted by unkleg

I have another question.

Is this rotary a 6 port or a 4 port

its a 6 port, and those are really good motors.

unkleg · 11-11-2011, 11:21 PM

Good news all I was able to rebuild the motor had to buy new rotors and housings. The apex seals looked like they were playing around in there for a while(did not look pretty)
Now new problem.
I installed the motor turned it over and fired right up (smoked so bad wife got pissed and had to shut it down) now it will not start again and just floods. I have tried clamping off fuel and just shooting in a little at a time and still will not fire. I thought maybe plugs so bought new ones and still nothing. Any tricks I can try?

eprx7 · 11-21-2011, 10:18 PM

Disconnect the fuel pump wiring or just pull the fuse for the fuel pump, remove the spark plugs and crank the motor to get excess fuel out of the motor. Then put the plugs back in and make sure that they are clean and dry. Make sure that your timing mark is right, check the FSM for instructions on setting timing. After that it should fire right up. Then after you let it warm up (without your wife around) and the check the timing again. That sould get your electrical side work out, then you may need to adjust the carb.

BTW I pre-mix my RX-7 with synthetic 2 stoke oil (Royal Purple) it cost more that normal 2 stroke oil but it doesn't smoke or smell like a chain saw. I have been running it for about 5 yrs now no problems, I use 1oz.per gal. Good luck and nice car by the way.

09-11-2011, 06:58 PM	#1
unkleg The Newbie Join Date: Sep 2011 iTrader: (0) Posts: 10 Rep Power: 0	Need your Help - Mazda 13b motor in a Manx Hello all, I need your help I have a Mazda 13b motor in a Manx. I think the motor is a 1985 but not sure is there any way of telling what year it is. Now the reason I ask is, it's been running really poor and I thought it needed a tune up so I did that and still running bad so I asked on RX7 site and they said it's a carb. problem so I over hauled the carb. WELL GUESS what it still runs bad. So I did a compression test and the front rotor has 0 yes zero pressure. So I think I need to rebuild it. Any help would be great Thanks in advance. Greg

09-11-2011, 07:22 PM	#2
FerociousP I-had-a-bad-experience... Join Date: Feb 2008 Location: M'boro iTrader: (2) Posts: 1,046 Rep Power: 18	Post detailed pics and your question will be answered within a few hours!! and if it did read zero you would definitely need a rebuild. What was the compression of the other rotor? __________________ '15 Juke Nismo '06 MX-5 GT SOLD '04 S Silver RX-8 GT Track Day Use SOLD '90 Black TII vert w/ Sprint RE stock port/turbo DD dyno (242.6whp@5500rpm @12psi 8psi@redline) and (250ftlbtq@4800rpm @13psi) SOLD '89 GTUs 6p TII SOLD, '87 sport SOLD, '79 SA stock SOLD '91 B2600i 4x4 w/ Rx-8 LSD SOLD

09-11-2011, 08:20 PM	#3
jfaplanet Rotary Fanatic Join Date: Feb 2008 Location: Smyrna, TN iTrader: (0) Posts: 134 Rep Power: 17	re:Help Unkleg, what kinda help are you needing, if you do indeed have 0 compression on a rotor, then you do need a rebuild. If you motor is an 85 13b it is from a GSL-SE and the last year that they built that style of motor. There are options but we need to know what type of engine mounts you are using. Post up some pics and someone is sure to help. Where are you located may be helpful also.

09-12-2011, 09:03 AM	#8
FerociousP I-had-a-bad-experience... Join Date: Feb 2008 Location: M'boro iTrader: (2) Posts: 1,046 Rep Power: 18	I does look like a 13b from a 1st gen... I hope you were premixing... and that the timing is/was set right. __________________ '15 Juke Nismo '06 MX-5 GT SOLD '04 S Silver RX-8 GT Track Day Use SOLD '90 Black TII vert w/ Sprint RE stock port/turbo DD dyno (242.6whp@5500rpm @12psi 8psi@redline) and (250ftlbtq@4800rpm @13psi) SOLD '89 GTUs 6p TII SOLD, '87 sport SOLD, '79 SA stock SOLD '91 B2600i 4x4 w/ Rx-8 LSD SOLD

11-21-2011, 10:18 PM	#15
eprx7 Rotary Fan in Training Join Date: Sep 2008 Location: Copley, Oh iTrader: (0) Posts: 38 Rep Power: 0	Disconnect the fuel pump wiring or just pull the fuse for the fuel pump, remove the spark plugs and crank the motor to get excess fuel out of the motor. Then put the plugs back in and make sure that they are clean and dry. Make sure that your timing mark is right, check the FSM for instructions on setting timing. After that it should fire right up. Then after you let it warm up (without your wife around) and the check the timing again. That sould get your electrical side work out, then you may need to adjust the carb. BTW I pre-mix my RX-7 with synthetic 2 stoke oil (Royal Purple) it cost more that normal 2 stroke oil but it doesn't smoke or smell like a chain saw. I have been running it for about 5 yrs now no problems, I use 1oz.per gal. Good luck and nice car by the way. __________________ 1979 SA F Prepared solo/ Track day car 12a w/Weber carb,RB header and exhaust, Ground Control coilovers, camber/caster plates GforceEng.panhard rod w/ tri-link,Panasports wheels w/Hoosier slicks.

09-11-2011, 09:49 PM	#7
dream36realms Rotary Fan in Training Join Date: Aug 2011 iTrader: (0) Posts: 32 Rep Power: 0	looks like the gsl-se oil pan on there Thats all I can add

09-12-2011, 11:41 AM	#11
unkleg The Newbie Join Date: Sep 2011 iTrader: (0) Posts: 10 Rep Power: 0	OK, so now after reading that I guess I am looking for a GSL-SE block if anyone knows where to go to get one. Please let me know and this time I will make sure to add oil to the fuel. I am looking in my area on Craiglist but found nothing so far. I really want to thank you for all your help.

09-14-2011, 05:51 PM	#12
unkleg The Newbie Join Date: Sep 2011 iTrader: (0) Posts: 10 Rep Power: 0	I have another question. Is this rotary a 6 port or a 4 port

11-11-2011, 11:21 PM	#14
unkleg The Newbie Join Date: Sep 2011 iTrader: (0) Posts: 10 Rep Power: 0	Good news all I was able to rebuild the motor had to buy new rotors and housings. The apex seals looked like they were playing around in there for a while(did not look pretty) Now new problem. I installed the motor turned it over and fired right up (smoked so bad wife got pissed and had to shut it down) now it will not start again and just floods. I have tried clamping off fuel and just shooting in a little at a time and still will not fire. I thought maybe plugs so bought new ones and still nothing. Any tricks I can try?