Engine r.p.m.
04-03-2008, 08:44 PM
#1
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Engine r.p.m.
Installed a sendec tach in my 50" Bonzi today , with a propshop 7016 2 blade at 45mph in choppy water it read a max rpm of 14,560 . I have nothing to compare this with the engine is a modified zenoah BZX4 (Bonzisports) I'd like to see low 50's if possible I was thinking about a 3 blade maybe a propshop 6717 to get more rpm and topend speed. Opinions please fellas.
04-03-2008, 09:01 PM
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RE: Engine r.p.m.
pretty low for a "mod" motor. My stock Zenoah 260 was turning 15930-15960 consistently with a X472 prop on my mono. My mono with J&G topend zenoah with 7016/2 was turning 17700-17800, and with X472 was turning right around 18,000. My cat with CC Racing Zenoah 260 turns 17700-17800 with 6717/3 410-C, same cat with my QD25 turns 18800-19000 with same 6717/3.
04-04-2008, 11:11 AM
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RE: Engine r.p.m.
ORIGINAL: ken0276
Sure I believe it if not I wouldn't have sold all those engines and joined in 260 team.
ORIGINAL: martno1fan
Well would you BELIEVE IT lolol
Well would you BELIEVE IT lolol
04-04-2008, 05:18 PM
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RE: Engine r.p.m.
ORIGINAL: SUPER-V
The exhaust is a Bonzi race pipe with V-header . What brand tach's are you guy's using ? The sendec only reads to 16,000 rpm.
The exhaust is a Bonzi race pipe with V-header . What brand tach's are you guy's using ? The sendec only reads to 16,000 rpm.
04-04-2008, 05:47 PM
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RE: Engine r.p.m.
ORIGINAL: SUPER-V
The exhaust is a Bonzi race pipe with V-header . What brand tach's are you guy's using ? The sendec only reads to 16,000 rpm.
The exhaust is a Bonzi race pipe with V-header . What brand tach's are you guy's using ? The sendec only reads to 16,000 rpm.
04-05-2008, 07:44 PM
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RE: Engine r.p.m.
ORIGINAL: martno1fan
Cool thats better than making waves qd
.
Cool thats better than making waves qd
.
04-06-2008, 10:49 AM
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RE: Engine r.p.m.
ORIGINAL: ken0276
More then that mart, your 260 could blow his qd away too if you set you boat right..lol
ORIGINAL: martno1fan
Cool thats better than making waves qd.
Cool thats better than making waves qd
.
.Mart
04-07-2008, 07:21 PM
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RE: Engine r.p.m.
ORIGINAL: ken0276
More then that mart, your 260 could blow his qd away too if you set you boat right..lol
ORIGINAL: martno1fan
Cool thats better than making waves qd.
Cool thats better than making waves qd
.
I think you need a head check. The boat went over 70 and the video proves it....just cause the gps went out of the frame for TWO SECONDS doesnt mean we switched it for an identical one with a programmed reading of 70.4.
Thats absurd and I think you should change your signature and drop the hating.
Sincerely
Matt Gunn
04-08-2008, 01:14 PM
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RE: Engine r.p.m.
ORIGINAL: webdr
I see your sig and it makes me sick. Listen up son, I shot that video, I set the GPS, I KNOW what it said and there was NO funny business what-so-ever. When you call Will a liar, your calling me a liar, and I dont like that. The boat ran 70.4mph plain and simple. why in the H-E-L-L would I make it up???????? Tell me that Kenny....why would I lie? No, seriously, I WANT you to tell me why I would go out there and make a PHONY video of a boat going 70mph. I write for RCU as a reviewer, do you think I want my name out there as a phony? For something as trivial as a model boat top speed? Hell no...
I think you need a head check. The boat went over 70 and the video proves it....just cause the gps went out of the frame for TWO SECONDS doesnt mean we switched it for an identical one with a programmed reading of 70.4.
Thats absurd and I think you should change your signature and drop the hating.
Sincerely
Matt Gunn
ORIGINAL: ken0276
More then that mart, your 260 could blow his qd away too if you set you boat right..lol
ORIGINAL: martno1fan
Cool thats better than making waves qd.
Cool thats better than making waves qd
.
I think you need a head check. The boat went over 70 and the video proves it....just cause the gps went out of the frame for TWO SECONDS doesnt mean we switched it for an identical one with a programmed reading of 70.4.
Thats absurd and I think you should change your signature and drop the hating.
Sincerely
Matt Gunn
04-08-2008, 03:00 PM
#22
Thread Starter
RE: Engine r.p.m.
Took the boat out today , checked everything throttle etc. 14,600 rpm @ 44 mph , leaned it out a hair picked up one mph @ same rpm. sounds like i'm missing 2,000 rpm. Where are you guy's hooking your tach wire mine is wrapped around the spark plug wire as per instructions , someone said I might get a more accurate reading by connecting to the black wire from the coil , any input is appreciated . This was with a Propshop 70/16 2 blade prop , Bonzi BZX4 motor & race pipe.
04-08-2008, 05:20 PM
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RE: Engine r.p.m.
Most i know seem to use the black wire you mentioned,by the way try a 6717/3 blade prop from dasboata for your boat.Better still email him and ask his recommended prop for your settup,but i find that prop perfect for a stock zen in a vee as per his reccomendation .
[link]http://www.dasboata.com/[/link]
.[link]http://www.dasboata.com/[/link]
04-08-2008, 06:13 PM
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RE: Engine r.p.m.
ORIGINAL: SUPER-V
Took the boat out today , checked everything throttle etc. 14,600 rpm @ 44 mph , leaned it out a hair picked up one mph @ same rpm. sounds like i'm missing 2,000 rpm. Where are you guy's hooking your tach wire mine is wrapped around the spark plug wire as per instructions , someone said I might get a more accurate reading by connecting to the black wire from the coil , any input is appreciated . This was with a Propshop 70/16 2 blade prop , Bonzi BZX4 motor & race pipe.
Took the boat out today , checked everything throttle etc. 14,600 rpm @ 44 mph , leaned it out a hair picked up one mph @ same rpm. sounds like i'm missing 2,000 rpm. Where are you guy's hooking your tach wire mine is wrapped around the spark plug wire as per instructions , someone said I might get a more accurate reading by connecting to the black wire from the coil , any input is appreciated . This was with a Propshop 70/16 2 blade prop , Bonzi BZX4 motor & race pipe.
Hello Super V,
I don't know about the tacho you are using. I have not run the hull you are using. Or the engine you are running. However, I would guess the reason your engine is not reving to where you want it to and the boat is not as quick as you expected to be down to hull trim.
You will gain more from setting up the hull correctly and ensuring the hull is as "clean" as it can be than you will with engine tinkering. That is, assuming your engine is running OK and driving an appropriately sized prop. I would say from the revs and speed you state that the prop sounds too big, but, if the boat is not trimmed right, then this would account for the speed deficiency and resultant the low revs.
Glenn
04-08-2008, 10:40 PM
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RE: Engine r.p.m.
Super V, that 14+ K RPM is what a stock eng. will run at. The setup on the boat might be wrong, but there are other issues to address. A 7016 stock prop has a pitch of 4.4" and given the weight of the 50" hull, might be too much for the modded motor. Your Bonzi V header is too long to provide the proper tuned length to help the motor get on the pipe and build the RPM. You need a shorter 90 deg. header. Make sure you have the C of G set at about 30%, and that your drive angle is O to the hull's running surface. If you have trim tabs on it, make sure they are set at O as well, until you get the RPMs up. If the back few inches of the hull's running surface has a hook in it, the bow will run too low and drag too much hull in the water, loading down the eng. Check the color of your spark plug after a few fast laps around the pond. It should be a toasty brown color if the high speed needle is set right.