Knock Sensor and Trailer Modification Question

[Bryce]

Hi,
This weekend when I got my boat out of storage (2008 22ve) I tightened the impeller plate and put in the 2 drain plugs and 2 knock sensors. I noticed that the starboard knock sensor threaded in smoothly, but not so much for the port side. I looked at the engine block and saw some sedimentation in the threads. I picked at it with a nail and any other sharp object, but to no avail I couldn't get it all out. I got the knock sensor to fully seat in but when I removed it to double check, the threads on it got wore down some (no longer coming to a sharp point on the sensor threads, which appears to be brass). Should I be concerned at all about this or just leave it alone and when winterizing next year replace it if need be? Has this happened to anyone else? With it being on the low point in the engine it is prone to having water there all winter long.

My second question is about trailer. I recently got an Acme 1235 from Chpthril and it leaves so little clearance (as in virtually none) between the bottom of the prop and the steel guard frame of the trailer it will most definately get messed up even with launching the boat in deeper water so it floats off. Am I better off having a metal shop cut/fab. the bottom guard to lower it a few inches, of just remove the 2x4" rails from the boat and put 2x4" pressure treated blocks under every contact point to essentially raise the rails 2" and get the clearence that I need? Below is a picture with the arrow poinging to what I mean when I say there isn't enough clearence with the steel guard (not my boat but the picture shows what I'm talking about). My concern with lowering the guard frame is that is will give me even less road clearence, so backing up a somewhat steep driveway might be impossible. My concern with adding blocks under the rails is that my bow hook might then be higher than my rubber stop by the winch. What should I do???

Any suggestions are appreciated.

Thanks,
Bryce

[ajholt7]

As far as the trailer you could lower the gaurd and add rollers to it incase it bottoms out.

[Bryce]

I thought about rollers but the way the boat sits now, there is maybe 1/8" clearence between bottom of the prop and the guard. Since the guard angles up towards the back I am afraid that unless I do a deep launch and really get the boat floating the prop will hit the guard, so I'm not sure how rollers would work for that. Maybe just lifting the rails would be the easiest thing for me to do, but open to ideas.

Thanks,
Bryce

[highrock]

It looks like he already has the rollers at the bottom of the trailer. I would do whatever is easier. If you do drop the back of the trailer you may need to get a lower drop hitch to compensate.

If you raise the bunks on the trailer you will also need to do something about the roller at the bow stop as well

[Bryce]

Highrock,
I don't currently have rollers (the pic is not of my boat). What would I have to do for the bow hook? Is it possible to raise the back bunk/pad by 2", the middle by 1", and leave the front alone so I don't have to mess with the bow hook/stop, or would that not allow the hull to sit and rest properly with weight evenly distributed?

[highrock]

You may be ok only raising the back and the middle. I think that would be your best bet and you could leave the bow hook alone. I would just try to make sure the boat rested evenly on the bunks.

[majestic]

Bryce- Just curious what make of trailer do you have?

[Bryce]

I have an 08 tandom DHM.

[Bryce]

Any insight on the knock sensor issue?

[MoneyPity]

If you store boat in garage you may want to make sure if you raise the boat by 1-2 inches that it will still get through the garage door. When I first got mine I had to modify the Vantage trailer my dealer sold me. To compensate for a 7' door and a high trailer with a Tower folded and the angle the boat went into the garage I had to drop my bunks about 3".

Even after I replaced the Tige E-Series tower with the Samson Sports Razor clearance is still tight. If I don't push the tower all the way down it will still rub my garage sill. I bought the largest drop down hitch I could find and the first time I tried backing the boat up my 25 degree driveway incline the the drop down was bent so bad that I almost was not able to get back on the street to go back to my normal hitch. Getting my 20V into my garage is a challenge. It goes into the middle stall which has a two car wide door while slot three has an 8' opening. The middle slot has a support pole on the port side of the boat and I have to get the boat as close to that pole as I can which is usually 3-4 inches so that there is room for Tahoe in the left space and the Mustang to the right. It will take me a bit to get her where I want so doors don't hit the boat or the Tahoe and that we don't have to open garage overheads to get to the mustang slot and tools.

[Joeprunc]

As far as knock sensor, I would recommend getting a the proper tap and cleaning out the threads on your block. Your knock sensor should be fine, I'd maybe recommend wrapping the threads with teflon tape before installing it again.

As far as the trailer I'd probably just cut and weld the prop guard, and throw some wheels on the guard so when you bottom out it rolls nicely . I am afraid of body lifts on trucks, and I wouldn't do it on the trailer, especially with wood (maybe Aluminum or Poly Urethane blocks).

So your new prop is a larger diameter than your previous prop...is there any clearance issue with your hull? Also I'm not sure you need an additional 2" of clearance, usually when you load and unload your boat the rear of the trailer is a few feet below (obviously depending on the angle of the ramp). Usually when people tear up props on their trailers its from drifting to the side and hitting their bunkers as their loading. I'd be more concerned with the width of the trailer prop guard. That's why I usually coast onto my trailer at minute speeds, and usually kill the motor before the boat hits the bunkers.

[Bryce]

Joe Prunc,
Good call on checking for clearence on the hull side. Before ordering the 1235 I called Tige and spoke to one of their engineers. He emailed me some technical verbage that basically said after a certain year they modified the drive shaft angle to leave enough room for a bigger prop.

I called Tige directly and spoke to Harvey Smith about the knock sensor. He said not to worry about the threads and if I remove the sensor this winter just take a wire brush to it to clean them out, if anything at all. I found his answer amusing when I asked him what torque to tighten them to. He said they don't even use a torque wrench and just give them a "good crank" until they are tight and seated!

A few days ago I was able to find a local metal shop that is fabricating 2 5"x5"x1" and 2 5"x5"x1/2" pieces of bar aluminun. I am going to put the 1" pieces on the end of the rear bunks, and the 1/2" pieces on the middle of the rear bunks in hopes of raising enough for the larger propeller, but keeping the slope gradual enough not to need to do anyting to the middle and front of the boat bunks. I was able to get these 4 pieces of aluminum for $85 shipped. I'll post pics once I get them installed next week.

Thanks for all of everyone's help!

Bryce

[Bryce]

Today I was finally able to get my boat into water and install the aluminum spacers for the bunks. I put a 1" spacer on the back of the rear bunk, and a 1/2" spacer in the middle of the rear bunk. I didn't have time to pull the 527 prop and put on my 1235. From what I can see, it worked very well. The boat is still evenly supported everywhere on the bunks and it added an additional inch of clearence between the prop and prop guard on the trailer. I did have to get longer bolts for the trailer, but all in all it took me less than 30 minutes to do the modification.

[chpthril]

Looks like you have found a reasonable solution to the prop guard clearance. That was probably a cheaper fix then cutting, welding, painting and new guard. let us now when you get the 1235 on.