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| High rpms http://mudmotortalk.com/mmt_v2/viewtopic.php?f=3&t=26512 |
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| Author: | breakuplandreneau [ Tue Feb 07, 2012 8:24 pm ] |
| Post subject: | High rpms |
So I went run my boat the other day and while running down stream in a pretty strong current my motor was turning 4500rpm's, I had no issues with my valves floating or my engine not running correctly, just a little concerned if I should be turning that many rpm's. Mods include HSR 42mm mikuni carb, roller rockers and billet pushrods, and bps twins, my rev box is supposed to be for 4350rpm's but apparently it's not cutting the ignition at what it's set for. Main concern is if I should be turning that many rpm's with a stock valve train ? Does anybody have any pics on what stock valves look like when they are shimmed ? |
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| Author: | duckduckboom [ Tue Feb 07, 2012 8:25 pm ] |
| Post subject: | Re: High rpms |
what does your prop look like |
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| Author: | craig [ Tue Feb 07, 2012 8:28 pm ] |
| Post subject: | Re: High rpms |
Ever had any head work done? If so...who? If your heads are stock...your valves are floating at those rpm's. |
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| Author: | breakuplandreneau [ Tue Feb 07, 2012 8:32 pm ] |
| Post subject: | Re: High rpms |
Prop is in good shape, no issues with the performance of the motor, as far as I know the heads are stock unless the valves are shimmed, my main question is if anybody knows what stock shimmed valves look like and if they have any pictures. |
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| Author: | craig [ Tue Feb 07, 2012 8:38 pm ] |
| Post subject: | Re: High rpms |
Did you buy the engine used? |
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| Author: | deadbird8 [ Tue Feb 07, 2012 8:47 pm ] |
| Post subject: | Re: High rpms |
| Author: | breakuplandreneau [ Tue Feb 07, 2012 8:53 pm ] |
| Post subject: | Re: High rpms |
Thanks deadbird8 this is what I needed to know, FYI I'm not running dual carbs, it's the single mikuni (BPS setup) that I have |
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| Author: | deadbird8 [ Tue Feb 07, 2012 8:56 pm ] |
| Post subject: | Re: High rpms |
| Author: | breakuplandreneau [ Tue Feb 07, 2012 9:47 pm ] |
| Post subject: | Re: High rpms |
Just pulled the valve cover and clear as day the valves are shimmed with the same shims as in the picture, i could clearly read "this side up", so I guess the 4500 rpm's that i hit earlier wasn't a problem, keep in mind that was running in a very fast current, when i was running in a slow to non-existent current that i was turning around 4300-4400 rpm's. |
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| Author: | garrettpearce [ Tue Feb 07, 2012 9:57 pm ] |
| Post subject: | Re: High rpms |
I'm having the same problem just installed new heads by calen blackdeath intake and mikuni and I'm turning 4700 plus I'm not sure why I'm turning up so much. Brand new prop |
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| Author: | breakuplandreneau [ Tue Feb 07, 2012 10:03 pm ] |
| Post subject: | Re: High rpms |
Maybe its the awesome ethanol that we're having to run in our motors! LOL, Just joking I hate that shiat! |
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| Author: | Beadlejuicejr [ Tue Feb 07, 2012 10:10 pm ] |
| Post subject: | Re: High rpms |
| Author: | garrettpearce [ Wed Feb 08, 2012 9:38 am ] |
| Post subject: | Re: High rpms |
No not really but more bottom end |
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