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Need some help, 1995 MX-Z issue

Need some help, 1995 MX-Z issue

Postby maxiracer » February 5th, 2018, 12:21 pm

Hey, I dusted off my old 95 MX-Z 440 (series 454, RAVE rotary valve motor) to run ovals with again, but am having a problem that I cannot seem to cure on my own and am asking for advice. Problem is on exit of corners I get a bog, that costs me a spot or two every lap, sled picks right back up, and reaches full shift with no issues, except the reoccuring bog, rpm drop on exit. Went through the primary, new spring, rollers, bushings, getting 8250-8300 rpms, down the straights, clutches are warm but not hot, so am not having a belt slip issue, carbs are slightly tilted to compensate for the corners and fuel sloshing away from the mains, piston wash and plugs look good, so I don't think I am too lean on the mains. Anybody else have this issue and found the cure? I think it's something simple I am overlooking, but just can't seem to figure it out.
Thanks in advance!

Max
[b]Bevra Vintage Ice Oval Racing. Old School rules...[/b]
maxiracer
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Re: Need some help, 1995 MX-Z issue

Postby Spy-Guy 74 » February 5th, 2018, 1:15 pm

Maxi I would tend to think you have a carb issue with the information you shared in your post. Have you tried to tilt the carbs a little more than you have them now? Seems your starving for fuel in the middle of corner to exit, most of the time that has to do with amount of fuel in float bowl.

Another question on your clutching are you clutched for a 1 to 1 ratio or are you trying to reach over drive? Many people clutch and gear for over drive or a ratio more than 1 to 1, but it is the easy to get slippage when doing so. When we first started racing I believed reaching over drive with the clutch was the way to go, now I believe it still works sometimes but you'll be more consistant without it.
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Re: Need some help, 1995 MX-Z issue

Postby maxiracer » February 5th, 2018, 2:54 pm

Hi Spy,

Trying to stick with a 1:1 ratio, probably could stand to drop one fang to a 22 instead of a 23, but really had good success with the 23/44 ratio over the years. I am running the non-roller secondary with a HRP black ice 44/40 helix with 17 lbs of pressure on the beige spring, and backshift seems to be good, but I used to run 18-19 lbs in the past so I am hoping that clutching is not the issue. I agree it sounds like a fuel related issue, I am running the baffle around the main jet, should I maybe pull that and try see if that was keeping fuel from the mains? I do have about a 10 degree tilt to them now, go a bit more and raise the float level to compensate?

Thank you for the help!

Max
[b]Bevra Vintage Ice Oval Racing. Old School rules...[/b]
maxiracer
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Posts: 177
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Re: Need some help, 1995 MX-Z issue

Postby Spy-Guy 74 » February 5th, 2018, 6:23 pm

Maxi

I have never tried removing the baffle, if one came with the carb then I used it. But really can't see where it could hurt you either. I guess I'd change the float a little and try more tilt as I feel you have a float bowl issue.
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Re: Need some help, 1995 MX-Z issue

Postby maxiracer » February 6th, 2018, 6:18 am

Thanks Spy! I am going to do a couple of things, going to raise the needles and see if it draws a bit more fuel out of the corner. Doug Flannery suggested putting the airbox back on as the cutaway, needle tube and needle jet were based on the restricted airflow of the air box. I have been running what doo gave me in regards to the needle, cutaway and such, the only real difference is I pulled the airbox and rejetted. Also going to add more tilt to the carbs than the 10 degrees I have going on. I didn't get into the carbs last night, but know I have a 2.5 cutaway.

Thanks for your help, I am sure I will have more updates as we get ready for this weekends races.


Max
[b]Bevra Vintage Ice Oval Racing. Old School rules...[/b]
maxiracer
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Posts: 177
Joined: May 14th, 2001, 1:14 am
Location: Sparta....Cultural center of the universe


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