Mercury XR4 Lower unit Problem HELP!!!

[julesstar]

Thank You ALL for your help! What a great site this is. I did find a wire that had a spot where it was won down and was making contact. I fixed the problem and as I was testing it on the water...I was doing about 30MPH when my engine reved high for a second, I shut her down and NOW...It won't go into gear forward or reverse??? I hate to bother you guys but My father-inlaw has a 1989 Mercury 115HP VRO that the lower unit is good. He said I am welcome to it if it will work the power head?? is Bad on it but he said he had the lower unit rebuilt about a year ago...Does anybody know if I could be soooo lucky that this lower unit could fit on my 1989 150XR4 Black Max?? Please HELP!!! This is my 1st boat and my wife already wants to ring my neck!!! LOL Thank you in advance for any help you can give me.

 

[jimc_LA]

Re: Mercury XR4 Lower unit Problem HELP!!!

From what you describe, it sounds like you may have just spun the hub on your prop. I would check that first before deciding that the lower unit went out.

I would think that if the lower unit went out, there would have been some sort of a clunk or gear noise. Prop hubs sometimes go out under load simply because they're old. Had one do that to me.

Hope that it is just the hub. That's a much cheaper fix.

 

[shep70057]

Re: Mercury XR4 Lower unit Problem HELP!!!

You could start it in the drive way on muffs and see if it actually goes into gear or not.... I don't know that I would try to keep the prop from spinning though. At least you will know if the propshaft is turning or not.

 

[jimc_LA]

Re: Mercury XR4 Lower unit Problem HELP!!!

What shep says would be a good test. If the prop turns when you put into gear out of the water (no load) it would be an indication that the hub is spun. Sometimes when you spin the hub, it tears apart so bad that it gives the impression of not going into gear at all.

 

[thinksun]

Re: Mercury XR4 Lower unit Problem HELP!!!

Check prop as stated and hope for best.

I believe the lower unit is the same and will fit but the gear ratio is very different. Although the props are interchangable you may need a big increase in pitch. The 115 may be 1.87 or 2.0 ratio and the XR4 is 1.78.

I had the prop shaft shear on my 1988 XR4 which was a common problem due to a manufacturing defect (laser 2 prop went down 200 feet never to be found). I later grenaded a bearing and rebuilt gearcase for $2000 to just have it blow again. I found a used 5" case (XR4 and 115 has smaller 4" case) with factory nose cone and low water pick for $1200 and never had a problem after that.

I know the wife thing and "toy boy" as she called me filed for divorce. Being a slow learner I remarried -but to one that appreciates the cost of fun and toys.

Good Luck