Only hitting 7860 RPM?????

Snowmaker10 · Dec 26, 2016

I'm only hitting 7860rpm on my CARB M7/800 BB. I have replaced secondary spring with new, bushing on secondary, tried 2 new belts, cleaned PV's, adjusted cables, down to 63g weights in primary, adjusted compression adjuster (06 10") on secondary .59" in and also has shift assist. Possible that it's lean?? Plugs look grey. Any help would be appreciated.

WyoBoy1000 · Dec 26, 2016

Motor mounts shot

Snowmaker10 · Dec 26, 2016

WyoBoy1000 said:
Motor mounts shot

Even on a stand it won't hit over 7800rpm. Mag side is new. Only thing that changed really from last year to this year is adding the big bore. Mounts don't looked fracked or tore. ?????????

WyoBoy1000 · Dec 27, 2016

Power valves not working correct or need adjusted.

mbcat · Dec 27, 2016

Snowmaker10 said:
I'm only hitting 7860rpm on my CARB M7/800 BB. I have replaced secondary spring with new, bushing on secondary, tried 2 new belts, cleaned PV's, adjusted cables, down to 63g weights in primary, adjusted compression adjuster (06 10") on secondary .59" in and also has shift assist. Possible that it's lean?? Plugs look grey. Any help would be appreciated.

Toss that **** assist in the bush and get Mel to cut your sec hub off & replace w steel

Snowmaker10 · Dec 27, 2016

WyoBoy1000 said:
Power valves not working correct or need adjusted.

Power valves work fine, and they are correctly adjusted. Is the shift assist holding back some rpm? Pulls hard and feels like it wants to keep going it's just doesn't.

mbcat · Dec 27, 2016

Snowmaker10 said:
Power valves work fine, and they are correctly adjusted. Is the shift assist holding back some rpm? Pulls hard and feels like it wants to keep going it's just doesn't.

Who's big bore kit? Assist kills 200rpm. You rejet? That white sec spring is prob light too.

Snowmaker10 · Dec 27, 2016

mbcat said:
Who's big bore kit? Assist kills 200rpm. You rejet? That white sec spring is prob light too.

D&D cast 800 cylinders. They say 8200 for peak power. Running the cat orange spring in secondary. Also jetted up 1 main jet size.

Thunder101 · Dec 28, 2016

If they are DD big bore call DD to get everything needed for your carb and I'm sure it needs a timing key. And 8200 on what pipe ?

mbcat · Dec 28, 2016

Snowmaker10 said:
D&D cast 800 cylinders. They say 8200 for peak power. Running the cat orange spring in secondary. Also jetted up 1 main jet size.

8200 w monster pipe timing & fuel

Snowmaker10 · Dec 28, 2016

I'm running a 2* key as well as 100 leaded fuel. Running stock pipe.

Snowmaker10 · Dec 28, 2016

What about this?

mbcat · Dec 28, 2016

Snowmaker10 said:
What about this?

That won't help

Snowmaker10 · Dec 29, 2016

Well, got the motor mount plate off to find both mounts torn, so overnight parts from Japan(countrycat)

bigjb · Dec 29, 2016

Get used to changing them. They don't last all that long stock and adding hp doesn't help much. Also check the adjustable stopper too.

bigjb · Dec 29, 2016

I don't know anything about the carbed set ups but when i bb'd mine i had to add quite a bit of fuel especially up top, i was running twins though. When it was stock i was running 65g to hit 8100 with the twins so I would think 63 would be more than enough to get you up to 8200. I hit that 7800 wall when I did mine, took alot of tuning both fuel and clutching to get rpms up but it was very worth it.

WyoBoy1000 · Dec 30, 2016

Your comment of pulls hard but won't hit rpm is typical motor mount issue. Pulls engine out of alignment and pulls down rpm.

Replace those and buy a Lindemann mount that goes on the top of the mag side.

Otherwise you will never get full power to the track, never!

Thunder101 · Dec 30, 2016

X2 on the mounts and that generation needs help with mounts for sure. I also remember DTR finding the Carb models had less timing stock then efi models. Probably Cat making sure efi sleds were faster then carb sleds.
Also stock pipe with a DD y pipe made peek HP at 7850 on a 700, don't see why it would be different w 800cc or at least very close to it. As Said 8200 with Monster pipe.
I remember running 65gr on a 800 bb.

Snowmaker10 · Dec 30, 2016

Thunder101 said:
X2 on the mounts and that generation needs help with mounts for sure. I also remember DTR finding the Carb models had less timing stock then efi models. Probably Cat making sure efi sleds were faster then carb sleds.
Also stock pipe with a DD y pipe made peek HP at 7850 on a 700, don't see why it would be different w 800cc or at least very close to it. As Said 8200 with Monster pipe.
I remember running 65gr on a 800 bb.

Awesome. Ya, I'm running a 2 degree key, and will go back to the 65gr weights. I have heard at altitude these don't like an aftermarket pipe? If anything the bmp stealth pipe is all I have heard.

Cat800 · Jan 4, 2017

Did the new motor mounts fix your problem?

Only hitting 7860 RPM?????

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