Bobs nose cone install

[bildit4u]

Tips for installing a Bobs nose cone on a Merc 200 lower unit, heard a few things but would like to hear some instruction and direction from those who have installed them. Thanks or the input

[bigbore]

thats how bobs does it.:cool:

[Hydropromax]

Send it to Bobs, they have gotten better in the past few years. I have had problems with the bondo coming off. :thumbsup:

[bildit4u]

Does it make any difference and this is some of my question, if the point of the nose cone is centerlined with the prop shaft, or if it should be pointed slightly downward, I am putting the lower unit on a mod vp style tunnel hull with a full interior, have heard pointing the nose cone downward will give some bow lift, anyone had experience with this, Im thinking centerline the cone and let the air lift the hull. Anyones experience and input with this is appreciated. Thanks

[boilerdawg]

heres a post i made last year when i installed the cone on my cle. http://forums.screamandfly.com/forums/showthread.php?t=135154

i aint sure about tilting the cone down...i just tried to keep my level with the prop shaft as much as possible. also dont use bondo, weld it on and use the 2 part epoxy to fill any voids.

[Michael Dixon]

Do not tilt nose cone down if your running anything other than a v bottom. Expecially not if the boat is fairly light. That dog will bite you!!!!

[Riverman]

Four small tack welds to locate and four 3/4" welds to secure. Fill void with liquid West or equivalent. Find a GOOD welder to do the job for you - the castings are porous and difficult to weld.

http://i3.photobucket.com/albums/y66/river_57/cone.jpg

[bigbore]

Four small tack welds to locate and four 3/4" welds to secure. Fill void with liquid West or equivalent. Find a GOOD welder to do the job for you - the castings are porous and difficult to weld.

http://i3.photobucket.com/albums/y66/river_57/cone.jpg

Riverman knows.

[bildit4u]

The nose cone that I received from Bobs that they sent for a Merc lower unit has about a 3/16 gap between the nose cone and the verticle side of the gear case on each side, as I look at Rivermans gear case and nose cone fitment on the verticle side the nose cone fits snugly to the gear case, is this normal for the Bobs cone to fit loose with a 3/16 gap on each verticle side on a Merc gear case, or did BMS sent the wrong part, never having fit one before I dont know if this is correct part for the Merc or not.:confused: Thanks for all the input so far...............

[Riverman]

Many hours of grinding and fitting on mine. I had to adapt to a V4 case.

[K-Dawg]

Correct me if I am wrong guy's. I think that gap is filled with an epoxy filler. Then a light coat of bondo to shape and fair it in. I just cut one off of a busted GC the otherday and there was a metric f***ton of bondo and epoxy filler to grind out of the way to get to the tack welds. The metal cone had about the same size gap as you described.

[Riverman]

I think the trick to a good installation is plenty of prep work. I have a set 3/4" diameter burrs with big open cutting edges that are made for aluminum. Using lipstick or grease pencil, rub the gearcase where the cone will contact it. Hold the cone in place and some colour will transfer to the cone. Do a bit of cutting there and fit it again, over and over again until you are satisfied.

Only YOU can do the best job on something like this. Don't quit until YOU are satisfied. :thumbsup:

[Steven@BMS]

I have never personally done the install, so I can't comment, but I would recommend you call and speak with Kevin when you get a chance. If he is not available ask to speak with Robert. (813)247-7040

[JrCRXHF]

sorry to bring up a old post but i have a question.

I have a OMC V8 that someone else installed the nose cone. The bond that was around the cone and where the old water intake was cracked. when i cut out around the water intake about 6oz of water came out. The thing i worry about is in the winter in Michigan i don't want water in there because it might freeze and crack the lower unit. I was thinking of blowing down the nose cone input to see if i could get it out. Or is there so much room in there that ice will not pop it out.


To fix the bondo area i am going to use some of my carbon fiber to cover the problem area and then jelly resin over that.



Anyone's thoughts.

[marshan162]

If you have access to a lathe, an easy way to align the point of the cone is to hold the prop shaft in the chuck, and then bring the tailstock centre up to the cone. If it's not a large lathe you will have to lay the lower horizontally to clear the bed.

[Sheer Insanity]

Send it to Bobs, they have gotten better in the past few years. I have had problems with the bondo coming off. :thumbsup:


Couldnt you use JB Weld instead of bondo. It will be tougher to sand but much stronger.

[hydrostream79]

I have always had problems with the expoxy showing small cracks, from top to bottom where the cone hits the case. Kinda bugs me, but nothing major. I have fixed it several times, but they come back. I did have it welded in 4 different spots.

Any suggestions on a better material to use a filler?

[captglm]

If you go to a auto body paint store you can get a bondo type filler with fiberglass strands in it. its strong stuff. its a little harder to sand than regular bondo filler but well worth the extra effort. I think its called tiger hair.

GM ><>

[hydrostream79]

If you go to a auto body paint store you can get a bondo type filler with fiberglass strands in it. its strong stuff. its a little harder to sand than regular bondo filler but well worth the extra effort. I think its called tiger hair.

GM ><>

Thanks, I will check into that. Is that similar to the fiberglass jelly stuff that bondo makes?

[captglm]

Not really a jelly. its a higher strength better quality auto body filler that you can work just like bondo. you'll see small fiberglass hairs in the filler that keep it from cracking. We use it in restoring old classic cars where new metal pieces have been welded over rusted areas.

GM ><>

[hydrostream79]

:thumbsup:

[hydroholic]

Go to HomeDepot and go to where the hurricane clips are. The sell a double tube of stuff called Simpson strong tie. It is used for setting anchor bolts in concrete slabs. I forget what the strenghth rating is for uplift,but I can tell you that you will not ever get it up.You will pull up chunks of concrete all around it but it will not come up. It is a type of epoxy sorda like JB Weld but only a lot stronger. Have your cone tack welded on,fill most of it in with the Simpson strong tie. Shape it with the epoxy putty that came with the Bob's cone (you can buy it seperately from Bob's)and feather the rest with a thin coat of the fiberglass reinforced Bondo and it wont go anywhere.
Hydro

[JrCRXHF]

My question is does anyone have water in this part of the lower unit. I am worried about it freezing.

Not the nose cone that drains but where the old water pick was.

[Riverman]

The old water p/u passage should be filled with thickened resin. If you're worried about freezing, bring the gearcase inside for the winter.

[bigbore]

inside 4 the winter is a very good idea,but living in northern illinois the weather's so hard 2 predict (in spring n fall)could b cuttin your season off early.:cool:

[JrCRXHF]

yeah i wish i did not have to pull the lower unit every winter i just did not know if anyone else has had an issue with it.

[bigbore]

Sealed,had 1 on my xp 4 6 yrs.,it was fine.:cool: