sUZUKI MOTOR

[jay dezman]

Re: sUZUKI MOTOR

did you ever get the tach? seems like a blind change by dropping the pitch (especially that much. for any prop optimization, you need that tach. you could overspeed the motor (too much rpm) and the relevant damage that could cause....when will the tach be installed so there is hard data to work with?

 

[pmassey31545]

Re: sUZUKI MOTOR

Have not rec. tach yet but it's supposed to be here today-the 23rd. I put the 13 1/4x15 on and it comes out of the hole amazingly well. The rpm's are higher at WOT but I won't know what they are till I get the tach installed. Probably tomorrow, Friday. I'll let you guys know what happens when I get it all going. Like I said it runs much better with the new prop so I guess we'll see what the RPM's are doing soon. I appreciate all the help. Later...

 

[pmassey31545]

Re: sUZUKI MOTOR

Hello again. Got speedometer and tach installed Thyrsday night. Took the boat out Friday with the 13 3/4x15 prop and it was turning 6400 RPM's at WOT. Put a !3 3/4x17 on and it was turning 6100-6200 RPM's. Put the 13x19 back on and it would only turn 5200 at WOT. That's with me and my two sons. About 350lbs. tops. All props run the boat about 32-36 mph's. Guess my other speedometer was wrong. Like I said I've got great hole shot with the 13 3/4x15. But the 13 3/4x17 sucks. any suggestions? Also, when you give it full throttle from a stand still it still wants to hesitate. What could be causing this? Thank for all the help so far and any future help is greatly welcomed and appreciated. Still waiting for book...

 

[bossee]

Re: sUZUKI MOTOR

Hi,<br />Obviosly with 13 3/4 x 15 it over rev (6400).<br />Same with 13 3/4 x 17 (6100-6200).<br /><br />Question: did the over rev protection kick in?<br />(by decrease the RPM to something like 2000-3000 RPM to protect the engine)?<br /><br />With 13 x 19 it under rev some (5200).<br /><br />To the best of my knowledge the recommended max RPM at WOT for DT85 (it may be different with various year) is 5500 or 5600.<br /><br />Are you using Suzuki orginal black aluminium props when You test?<br />The prop selection is not that easy (different make and models in overwhelming numbers).<br /><br />Since You have a tach now You have all that is needed to try to find a prop that hit about 5500-5600 RPM at WOT with 1-2 persons onboard (average load). But You must be sure what manufacturer recommended max RPM at WOT is (it is written in Owners Manual). But I'm rather sure it is 5600 RPM for DT85.<br /><br />You know the rule of thumb what happen when You change the pitch (if all other factors are the same). But You have the diameter (and rake and cup) to take into consideration. Also the material (aluminium, stainless steel, composite).<br />It is trail and error I suppose.<br />If You keep in mind larger diameter gives good bite (more blade area) but more drag in water as speed increase You maybe can estimate the effect various props can have on acceleration and top speed (and also RPM).<br /><br />When You say the 13 3/4 x 17 sucks, how come it does that since it gives high RPM (6100-6200) at WOT? Does it not give good acceleration?<br /><br />It is probably not that easy in Your case since the boat is very light to keep RPM down at WOT and at the same time get good accelearation - could be difficult here.<br /><br />Maybe a 13 x 18 or 13 1/4 x 18 could be something to try (if You can find that)?<br />Or try a ProPulse since You can change blade pitch on these 2 pitch up or 2 pitch down (nr 8901 is probably what You want to try then, check the propulse.se site).<br /><br /><br />You may also want to read this for a general guide lines:<br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=36;t=000030 <br /><br />Also about Your boat, Invader 15 1/2 ft (1990):<br />I found a picture on internet on a 1970 invader 15 ft, is Your boat about the same?<br /><br />

 

[pmassey31545]

Re: sUZUKI MOTOR

Hey Bo. Thanks for the reply. Guess I'll start at the top and come down. First let me say that I THINK I got the tach set right. I'm not sure about how many poles and the instructions didn't help either. So any help there is very useful. NO, the over rev. protector did not kick in which makes me wonder if the tach is set properly. <br />The 15 and 17 props are Suzuki's and are black. the 19 is white so I'm not sure but it definitely fits.<br />I don't have an owners man. being that I bought the motor used.<br />The 17 doesn't really suck. It's just the 15 has great hole shot but over revs(if the tach is right). The 17 hole shot isn't as good and the 19 is even worse. Takes 3 1/2 minutues to get on plane. Not really, but it's slow. Maybe it's not over revving. Maybe I have the tach set wrong. There is a dial on the Suzuki tach on the back. It has 5 or 6 different settings for "poles". Don't know how many poles I have.<br />About the boat-it's not quiet that bad. Where did you find that thing? I think Noah may have used that after leaving the ark. Mine is 15'2" long and a V-hull. Sharp point/vee on front. I'll try to post a picture if I can figure it out. It cuts through the water well. Runs good but it just "seems" like there should be more. Maybe not. <br />Thanks for the help and info...<br />Paul

 

[pmassey31545]

Re: sUZUKI MOTOR

Hey Bo. Thanks for the reply. Guess I'll start at the top and come down. First let me say that I THINK I got the tach set right. I'm not sure about how many poles and the instructions didn't help either. So any help there is very useful. NO, the over rev. protector did not kick in which makes me wonder if the tach is set properly. The 15 and 17 props are Suzuki's and are black. the 19 is white so I'm not sure but it definitely fits.<br />I don't have an owners man. being that I bought the motor used.<br />The 17 doesn't really suck. It's just the 15 has great hole shot but over revs(if the tach is right). The 17 hole shot isn't as good and the 19 is even worse. Takes 3 1/2 minutues to get on plane. Not really, but it's slow. Maybe it's not over revving. Maybe I have the tach set wrong. There is a dial on the Suzuki tach on the back. It has 5 or 6 different settings for "poles". Don't know how many poles I have.<br />abotu the boat-it's not quiet that bad. Where did you find that thing? I think Noah may have used that after leaving the ark. Mine is 15'2" long and a V-hull. Sharp point/vee on front. I'll try to post a picture if I can figure it out. It cut through the water well. Runs good but it just "seems" like there should be more. Maybe not. <br />Thanks for the help and info...<br />Paul

 

[bossee]

Re: sUZUKI MOTOR

Suzuki DT85 1982 tachometer setting:<br />Probably 12 alternator poles so selector switch to 6P.<br /><br />Why I asked about Your boat was because it is somewhat easier to imagine how well a boat will run in the water by just looking at at a picture of it.<br /><br />It is not that difficult to post an Image here at iboats but You have to have some place on internet where You can upload the picture and then make the URL to that image.<br /><br />If You do not have that I can place it on a space I have. Just e-mail me the picture then (preferably JPG format) and I can make the picture show up here in this thread.<br />bo_edstrom@hotmail.com

 

[pmassey31545]

Re: sUZUKI MOTOR

Come to think of it my boat is similar to the boat in your avatar. I will check the setting cause I'm not even sure what I have it set on. I'll let you know something tomorrow. Thanks....

 

[bossee]

Re: sUZUKI MOTOR

Hi,<br />Here is my boat little larger then my avatar.<br />It is made in Finland (but I'm from Sweden), Yamarin 5820 (bowrider) 19 ft, with a Yamaha F115 4-stroke. It is from 2003 so I'm on my third season now with this boat.<br /> http://www.yamarin.com/index.cfm?ChangeSetNow=5 <br /><br />

 

[pmassey31545]

Re: sUZUKI MOTOR

My boat is very similar in shape and layout just shorter. Where can I find a top like the one you have- that buttons down. I have the buttons on the boat but no top. It would be nice to have on these hot sunny days. Didn't check the tach setting. haven't really had a chance. I'll probably take it out Tues. orr Wed. and report back after that. Later....

 

[bossee]

Re: sUZUKI MOTOR

Hi,<br />If the boat manufacturer, Invader, still is in business they should have via a dealer. Or maybe You have to custom made a new top. Probably not cheap if You want it made to fit exactly and have windows front, side and back as mine (on my top it is also possible to take the back half away and also take the rear window out).<br /><br />Or You could try a bimini top, it is more suited to give shadow from the sun. It is much cheaper then a complete top.<br /><br />Here in Sweden it rain in the summer sometimes and it is nice to have it completely covered then if You are out at sea.