boyesen reeds

[polaris1]

I have a 1996 johnson 130 v4 engine that was <br />rebuilt 2 years ago. (new pistons, bored 40thousanths over). Runs great, i am getting 6000 rpm at wot. I wanted to find out how noticable/benificail it would be to have boyesen reeds installed and the jets sized up 3 sizes. I have read on the boyesen website to expect increased throttle response as well as easier starting and idle. Any idea what the top end will do? (i am running this on a 2000 17 ft lund mtr pike)

 

[Dhadley]

Re: boyesen reeds

Welcome!!<br /><br />You'll get better throttle response but probably not much gain on top. Be careful about the jetting. You mention going up 3 sizes. On yours the idle should adjust and mid range is an air jet. Going up on an air jet is going leaner.<br /><br />Usually the idle is the only thing we need to change. Just make sure there's no spitting back at idle. Thats the one thing that will kill those reeds quick.

 

[polaris1]

Re: boyesen reeds

thanks for the input..i would have my mechanic do all the install (good to know about the jets) any idea how long it would take a mechanic to install these and make the adjustments?...also does this aid in starting in the cold morning temps ?....thanks again

 

[Dhadley]

Re: boyesen reeds

It might help on cold starts but that motor has the Quick Start feature and a primer system. It'll start almost instantly anyway.

 

[OBJ]

Re: boyesen reeds

And you want to be sure the mechanic is familiar with the installation of the reeds. The reed cages must be worked dead flat if the reeds are to operate as advertised. And they do make a difference in idle and response.

 

[R.Johnson]

Re: boyesen reeds

This is just a tip that may save you a problem. I have seen the mention of lapping reed block's flat by using a sheet of abrasive paper laid on a sheet of glass. A sheet of paper will roll up in a wave on the front of the part being lapped, this will give you a turned down edge on the leading edge of the part. You have very little material here. If you go this route, use fine paper, and paste it down, and let it dry with a weight on it. Lap very lightly, it's amasing how much plate glass will deflect by pushing on it. I'm talking about 1/2 inch thick glass here. Just a small granite surface plate, such as a 12, by 18 inch will be 3, to 4 inch's thick. It's a real handful to pick up.

 

[red boat]

Re: boyesen reeds

I added boyesen dual stage reeds to my 1990 XP-200 and gained 200 rpm on the top end but that increase was only seen with motor at full jack (6") anything less than that and the only increase will be throttle responce and that will be "seat of the pants". As dhadley said be really careful with jetting because incorrect jetting and a few motor coughs will split those reeds in half. Trust this, I didnt jet down and split 3 of the reeds in half within 25hrs of running because of the spitting back at idle (lean condition). Also on my motor I had to get larger high speed jets and was able to raise the timing 2 degrees. I also had to remove allot of material to get my reed cages flat, I could not belive how "untrue" those cages were stock but I guess with metal reeds it does not matter. I have approx 250 hrs on mine and they are still performing good. I think they recommend replacing them at approx 300hrs also??

 

[R.Johnson]

Re: boyesen reeds

red boat: How did you check those cage's? Check a set with prussian blue on a true flat surface. Lap with sand paper on a glass plate, and check again! Tell me about the improvement. Your scaring yourself over a mute point. Those reed's also have a gas, oil film acting as a seal. Lapping can be an exact science, you can't do it at the kitchen table with a piece of window glass, and sheet of sand paper.

 

[red boat]

Re: boyesen reeds

RJohnson,On the first set of reeds I did not do anything other than install them and run. I was getting some "sneezing" at idle and after approx 25 hrs I lost performance and was getting a blubbering sound so thats when I removed the intake to find split reed petals. When I installed the reeds on the cages for the second time you could see light between the cages and the reeds in several places, so thats why I went went to the shop and trued things up. I lapped the cages w/800grit wet sandpaper wetted with a cutting fluid on a approx 3/4" glass plate at a friends professional machine shop. After lapping each side of the cage we used some type of a purple liquid (cant remember the name of the stuff) and checked cage flatness the followed with a light lap with some type of machinists compound. I did have to remove quite a bit of that black gas,oil film seal from the cages to get them perfectly flat. I rejetted the carbs per boyesen's recommendations. Upon installation there was a noticeably better idle and much better throttle responce. On my boat (18.6 Checkmate Exciter 1200lb hull weight- not light but light enough for me)I gained a solid 250 rpm on the top end, propped, fueled the same. After putting approx 10 hrs on the reeds I increased the timing on the top end by 2 degrees (again per boyesens recommendations) and gained another 125-150 rpm's. The guys I was dealing with at Boyesen's tech support department were very helpful with their product. I am not trying to scare anyone just letting you know if you install the reeds and you get some "sneezing" at idle, get rejetted before you end up doing the job twice like I had to.

 

[R.Johnson]

Re: boyesen reeds

Depending on how sound the engine is, you alway's look for rejetting when going to fiber reed's. I would think that was more of the problem than lapping the reed box'es.

 

[red boat]

Re: boyesen reeds

I agree completely, that not lapping the reed cages was any part of the problem. After I added the reeds my motor started sneezing at idle. I did not think the sneezing would damage the reeds! Since I had to pull it all apart again Boeysen tech support told me to go ahead and true up the reed cages.