Can QL77JC4 cause missing? 95 115 60o

[jgrisham02633]

Can QL77JC4 cause missing? 95 115 60o

Recently replaced regulator cause tach didn't work, tach now works but motor cuts out at 4900rpm, i don't think it's a fuel thing plugs all look the same,compresion 130 on all, recently decarbonized, but did find out the plugs are not the recomended ones, could this be causing the top end cut out? runs well below 4900 just seems like 1 missing above?

 

[jgrisham02633]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

$$

 

[OBJ]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

J....the QL77JC4 is the recommended plug with the QL16V as an alternate. When you say cuts out, do you mean misses, stops, loses power?<br /><br />What's the engine temp like when running at high rpms? If the engine is runningat an elevated temp at high rpms, it could be causing the pack or some other part of the ignition system to fault.

 

[walleyehed]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

QL78YC is the recommended plug for the 95 60deg looper...

 

[jgrisham02633]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

Thanks for the post guys, I know i've been running the wrong plugs but could they cause the cutting out above 4900?, When I hit 4900 rmps will drop 400-500 untill I back off then they kick back in and so on. Thanks

 

[walleyehed]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

sounds more like an Ignition component failure to me....the plugs wouldn't make it "cut-out" at 4900...

 

[jgrisham02633]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

I have a manual on the way to help with the diagnosis, but is there a component that typically would be the cause of this problem?Coil, powerpack, stator? Thanks

 

[walleyehed]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

coil and/or powerpack would be my first thoughts.<br />Problem is, do we have a high temp issue causing something else.

 

[OBJ]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

Looks like my Part Smart is part dumb....the change in plugs didn't show up there.....

 

[seahorse5]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

For motors '96 and older, refer to bulletin 2292 revision #1. <br /><br />The only factory recommended plug chart is published each year in the official J-E Parts and Accessory Catalog.

 

[walleyehed]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

My Champ book says eagle series, '95-'98-QL78YC.....Maybe it's wrong, not yours???<br /><br />EDIT: My john-rude book says QL78YC for 60 deg 90 and 115 from 1995-up.

 

[rabidfish]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

My understanding was for all VRO equipped (QL78YC)

 

[walleyehed]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

seahorse, it appears we were typing at the same time above...so what plug is called for, I'm confused..

 

[seahorse5]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

QL78YC gapped at .030"<br /><br /><br />The factory made it easy, ALL looper motors, 40hp and up, use the QL78YC plug.

 

[OBJ]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

Yep....Seahorse is spot on..... <br /><br />A "Q" (supressor plug) is recommended for all VRO equipped engines.

 

[walleyehed]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

Wanted to make sure I wasn't giving bad info, thanks.

 

[OBJ]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

Me too Kenny. Guess I'm gonna have to copy the P&A book Spark Plug app's chart and take it home with me....

 

[clanton]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

Look for coil arcing from coil to metal plate between the coils and power pack.

 

[jgrisham02633]

Re: Can QL77JC4 cause missing? 95 115 60o

Re: Can QL77JC4 cause missing? 95 115 60o

Just thought I would let everyone know what the problem was, --wrong plugs! I was very glad when I got up to 5600 without a skip on my trial run after I put in the recomended (QL78YC)'s I am actually surprised because the plugs I had in were also Q's but I guess the longer electrode makes the difference. Thanks for the input everyone