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Kick


Hauling
Posts: 149
posted August 03, 2003 12:12 AM



I am new to this whole rotary motor thing. Here is the story for today.
While I went and picked up my rotary pickup on Friday, I cleaned it out today and it run good. I didn't have any problems with it at all. Well here is what happened today, I let my dads buddy drive my little pickup. None of us have driven a rotary pickup ever so this is 100% new to us. I was going to change the plugs, oil, oil filter, plugs wires, rotor, and cap, sometime this weekend. But my dads buddy and me took off to have a little fun and have him see what those little rotary motors could do. We took it down the street, and turned around. When he turned around he dropped the clutch and did a nice burn out. Then we shot right buy my house and turned around, I said hey lets do one more in front of them out side. So we did one more, it was almost a block long and didnít hook-up tell he hit 3rd gear. We went back down the street, and turned around and after that it started to run rough, like it didnít have power at 2500 rpm. We got it home and were thinking maybe a fuel filter. But after he left I went to turn it around so I could look at it some more, it did the same thing, it would idle fine tell you took off. I am worried about the motor; I am thinking maybe I did something to one of the seals. :(

I have no idea what to do from here right at this point. I changed the spark plugs, thinking maybe I failed them. But that didn't do anything. As of right now I have a 74 rotary pickup that runs fine at idle, but when you go to take off or have it get up there to 2500 rpm, it sounds bad, runs rough. My dad was thinking maybe it was something with the distributor, but I have no idea.


Here is what itís doing...
Runs fine when idling, not going anywhere, just at a stop. Then after you get it up to 2500rpm it seems like it doesnít have any power, sounds kind of funny also, has like a low sound to it. If you try to drive it, it wants to die, but you can keep it going and drive it along. Just runs ruff and wants to die when driving it. But itís fine when itís idling.


What does a rotary sound like when its messed up, when a seal or something else in the motor is gone?
Does it still idle good when something is wrong in the motor?

____________
1972 Rx2 - no enigne or trans
1974 Repu - runs and drives
1976 Rx4 - no engine or trans (klaus42 old 4)
1977 Repu - Parts

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ovquick


Redlining
Posts: 253
posted August 03, 2003 11:57 AM

RE: May have Broke It

Look at the easiest, cheapest stuff first. Since it's been sitting a while you might have simply sucked up some crud from the bottom of the tank, check the fuel filter first, then make sure the line from the tank to the pump is clear, if thats ok, then move on to a fuel pump volume and pressure check.

       
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Jeff20B


Moderator
Posts: 661
posted August 03, 2003 01:36 PM

Yeah, replace your filter first.
____________
'74 REPU
'76 Cosmo
'77 MG Midget 13B
'81 RX-7

       
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roaddancer


Hauling
Posts: 127
posted August 03, 2003 06:22 PM

Check for a blown off vacuum line, could make that low sound, and gut the performance. Not that easy to blow a rotary, so look for other causes. Worst case is something got to the carburator jets and your secondaries ar dead. Doubt it though. Still simple enough to fix. Good luck!

       
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brad


Rotorhead
Posts: 1671
posted August 03, 2003 08:14 PM

what rpm

did you guys shift at? If you have a full pan of oil 7000rpms is ok. Over that iffy. Over 8500 not enough lubrication and bearings wear quickly plus apex seals chatter.
____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge

       
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Klaus43


Rotorhead
Posts: 1259
posted August 04, 2003 10:18 AM

If your oil is clean and fresh and full...

...and everything else was 'proper' enough to run well, you shouldn't have damaged anything below 8 grand... if your fuel filter and pickup tube--and fuel line, and carb. inlet, and float bowl (!) are all clean and happy: which distributor are you running? Could be an ignitor going out on the electronic ign., but more likely is a crappy electrical connection. That is, if you have ZERO vacuum leaks... if yours is like mine, there's a ton of stuff removed and blocked off. Each is a potential vacuum leak. Only a matter of time... Then again, there's a lot of potentially 'iffy' places in the aging electrical/ignition system... might be time to get out the meter and test it out for continuity/drops in voltage, etc... Might just be a loose connector! Spirited driving will help find those...
Might wanna lay off the one-wheel burnouts until you've given everything a good once-over... including D&R your trans. & rearend with the likes of AmSoil gear lube...
Get yourself some electrical contact cleaner/restorer from an electr. specialty place, and when everything's proper and clean, and you've done a full tune-up, get some AmSoil Power Foam, and clean out your motor. But only after it runs as well as you can get it to, first!

       
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wankel_dreams


Redlining
Posts: 293
posted August 04, 2003 10:42 AM

looks like the basics are covered

yeah sounds like might be lack of fuel to me too.
check:

fuel filter.

fuel pump. remove the fuel line at the carb and make sure you are getting ehough fuel to the carb. also if your REPU does have alot of stuff blocked off, check that the gas tank hasn't built up excessive vacuum.

junk in the carb(look in the sight windows to see if fuel levels are correct).

if it idles fine, ts probably not blown.


AND THATS WHY ONLY I DRIVE MY ROTARIES!!!!!
____________
74 wankel panther
77 REPU
79 rx7
89 Vert

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Kick


Hauling
Posts: 149
posted August 05, 2003 01:55 PM
Edited By: Kick on 5 Aug 2003 14:14

I picked up a new cap, new rotor, new plug wires, and plugs. Turns out, my distributor is from an '83-'85 Rx7. Maybe the motor is from that year, I really don't know. I also bypassed the fuel filter which didn't help any, it still ran wired after all this. We were looking down in the carb while it was running, and it looks like it was just dumping fuel in insted of a nice stream, I am thinking maybe its flooding out the motor when it needs more fuel. Could something like that happen? I was thinking maube I should rebuild the carb. It is a Holley 4bl carb setup, and it has sat for sometime before I got the truck. Is there any way I could tell what year the motor was built?
____________
1972 Rx2 - no enigne or trans
1974 Repu - runs and drives
1976 Rx4 - no engine or trans (klaus42 old 4)
1977 Repu - Parts

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brad


Rotorhead
Posts: 1671
posted August 05, 2003 02:45 PM

quote:
I picked up a new cap, new rotor, new plug wires, and plugs. Turns out, my distributor is from an '83-'85 Rx7. Maybe the motor is from that year, I really don't know. I also bypassed the fuel filter which didn't help any, it still ran wired after all this. We were looking down in the carb while it was running, and it looks like it was just dumping fuel in insted of a nice stream, I am thinking maybe its flooding out the motor when it needs more fuel. Could something like that happen? I was thinking maube I should rebuild the carb. It is a Holley 4bl carb setup, and it has sat for sometime before I got the truck. Is there any way I could tell what year the motor was built?


Like others have said, you just sucked some crud from the fuel tank all the way into the carb. I bet the needle and seat is plugged OPEN and just overflowing the float bowl, dumping fuel down the chokes.

Carb Rebuild Time! Not to worry.
http://racingbeat.com/FRmazda1.htm
Holley Gasket Kit
Part Number: 16643
Retail Price: $27.00
Qty:
Holley Gasket Kit
A Holley Gasket Kit is the quick, easy way to be sure you have all the necessary gaskets when you rebuild our 465 CFM and 600 CFM carburetors. The kit includes the primary and secondary bowl gaskets, the primary metering body gasket, eight float bowl bolt gaskets, and two transfer tube O-rings. The kit does not include the throttle body gasket, which is not normally disturbed.


Bypassing the fuel filter would contribute to crud in the carb. Put a new filter before the fuel pump and another before the carb. Fram G12 works fine for me.

As for what year the motor was built, unless the builder tagged the motor, you got receipts, or can contact the builder, no way to tell.

Do the rotor housings have the big all capital letters MAZDA on it or lower case mazda. Latter is later rotor housings, former are original old school seventies housings...


____________
-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge

       
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Kick


Hauling
Posts: 149
posted August 05, 2003 03:18 PM

Anyway I could tell if it's a racing beat Holley or just a regular Holley? The carb is still on the stock intake from what I can see. It has an adaptor so the Holley can bolt on the stock intake. That is what it looks like to me anyways.

Would that Holley kit work on any Holley carb?
____________
1972 Rx2 - no enigne or trans
1974 Repu - runs and drives
1976 Rx4 - no engine or trans (klaus42 old 4)
1977 Repu - Parts

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wankel_dreams


Redlining
Posts: 293
posted August 05, 2003 04:34 PM

quote:

Like others have said, you just sucked some crud from the fuel tank all the way into the carb. I bet the needle and seat is plugged OPEN and just overflowing the float bowl, dumping fuel down the chokes.

Carb Rebuild Time! Not to worry.



or the float is stuck or full of fuel. yup sounds like a carb rebuild is in order.
____________
74 wankel panther
77 REPU
79 rx7
89 Vert

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wankel_dreams


Redlining
Posts: 293
posted August 05, 2003 04:38 PM

quote:
Anyway I could tell if it's a racing beat Holley or just a regular Holley? The carb is still on the stock intake from what I can see. It has an adaptor so the Holley can bolt on the stock intake. That is what it looks like to me anyways.

Would that Holley kit work on any Holley carb?



I would hope that if someone spent the extra $$$ for a Racing Beat modified Holley, that they would also get the Racing Beat Holley intake manifold. So i'd guess that its probably not a Racing Beat Holley, but who knows.


____________
74 wankel panther
77 REPU
79 rx7
89 Vert

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Klaus43


Rotorhead
Posts: 1259
posted August 05, 2003 05:30 PM

If'n ya wanna diagnose it first...

...just get into that carb, and see what you find. I'll bet a bunch of varnish and crud... but that way, at least you'll know if you need a float as well, before you go get the kit. I like Berryman B-12 chemtool spray cleaner, but beware--it's nasty powerful stuff; dissolves blacktop...
While you've got the fuel line off the carb, might as well test for delivery volume, if not pressure...
'83-'85 distributor, fine, and good..but those years rx-7's had 12A's, not 13B's!

       
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Kick


Hauling
Posts: 149
posted August 22, 2003 04:28 PM

Well I am glad I am able to get back on this forum.

I took the carb off and was able to get it all apart, after doing that I noticed that someone had put a bolt were the power valve should have been. Maybe this is why it was running like it was. I am almost done putting it all back to together with a new kit in it.

I plan to run two new fuel filters also, one just before the carb and one were itís in the back,
Ill let you all know how it goes, thank you for all your help here.

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wankel_dreams


Redlining
Posts: 293
posted August 24, 2003 09:52 PM

[quote...I plan to run two new fuel filters also, one just before the carb and one were itís in the back....



alot of people run 2 fuel filters like that. I run 3. one right before the fuel pump, and two right before the carb. I know its overkill. Then when changing filter, i remove the rear one (dirtiest), rotate the front ones back one position, and install the new one right before the carb.
____________
74 wankel panther
77 REPU
79 rx7
89 Vert

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Kick


Hauling
Posts: 149
posted August 24, 2003 10:30 PM
Edited By: Kick on 24 Aug 2003 22:31

I put two that are see in to them, that way I know its getting fuel to them.

I am very happy to say, it's alive. :D
My 74 rotary pickup is back on the road. It turned out to be the carb.

I would like to say thank you to everyone here that gave me help and info about what to look at next.

Thank you,
:)
____________
1972 Rx2 - no enigne or trans
1974 Repu - runs and drives
1976 Rx4 - no engine or trans (klaus42 old 4)
1977 Repu - Parts

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Klaus43


Rotorhead
Posts: 1259
posted August 25, 2003 08:55 AM

Glad to help!

...if indeed all my blah, blah, blah was useful... BTW, fuel-filter overkill is not a substitute for a clean tank/pickup tube/fuel line, and pump...

       
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Kick


Hauling
Posts: 149
posted August 25, 2003 01:55 PM

Cleaning the tank/pickup tube/fuel line, and pump, will all be done when I take off the bed so my father can do some body work on the back.

:)
____________
1972 Rx2 - no enigne or trans
1974 Repu - runs and drives
1976 Rx4 - no engine or trans (klaus42 old 4)
1977 Repu - Parts

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