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Fishtailing and hobby horsing while towing 170 Montauk
|Author||Topic: Fishtailing and hobby horsing while towing 170 Montauk|
posted 10-20-2004 05:23 PM ET (US)
Whenever I tow my 170 Montauk I feel that it is fishtailing and hobby horsing more than I think it should. I tow with a full-size V8 pick-up so it isn’t much of a problem but we’re getting a lightweight pop-up truck camper for overnight trips with the boat and the truck should be close to GVWR so I’m afraid I would be loosing my margin of safety.
Does anyone else have this problem? I have the factory Karavan trailer and it seems to me that the rig should be better balanced so that this is not a problem. Is it because I have a 4 stroke and they failed to account for the higher weight when balancing the package? I’ve towed bigger boats with this truck and haven’t felt it as much. Would a load balancing hitch help?
posted 10-20-2004 05:52 PM ET (US)
You need to install a sway bar. Can purchase at most RV/trailer places. Works great on everything I tow. Wouldnt want to be without one.
posted 10-20-2004 06:44 PM ET (US)
Fishtailing can be caused by not enough tongue weight on the ball hitch. 60% of the weight needs to forward of the axle, 40% behind.
I moved my front winch stand forward about 6 inches and cranked the boat more forward on my trailer when I mounted a heavier 70HP 4 stroke on my 17' Newport. Tongue weight is now about 150 lbs. I tow with an Expedition with the air adjusting shocks, so it does not weight the rear of the truck down at all.
posted 10-20-2004 07:14 PM ET (US)
I had that problem but moved gear from the rear of the boat to the truck bed and to the bow. Do you have a receiver hitch with drop receiver to level the trailer with the road? Lowering the hitch ball might help. jim
posted 10-20-2004 09:07 PM ET (US)
I can't imagine that a boat/trailer rig the size of a MONTAUK 170 would be in the category of needed a sway bar.
Check the tongue weight. You probably can measure it with a bathroom scale. Usually any sign of fish tailing is an indicator of not enough tongue weight.
The minimum tongue weight should be about 5-percent of the total trailer/boat weight. Weight the whole rig on a certified scale to get an accurate assessment of its true weight.
As a technique for increasing tongue weight, it is better to move the axle aft than to move the boat forward, assuming the boat is properly positioned to the trailer frame.
posted 10-20-2004 10:31 PM ET (US)
Hook up your trailer and look at the whole rig from the side. Is your trailer frame level. Or does the truck frame and the trailer frame form a "V" or inverted V "A". You'll need to get a drop hitch or a hitch with less drop until the whole rig is level. If they are not level you are constantly stretching and compressing the V. Which will result in "bucking" or hobbyhorsing.
I had a friend tow a 21 foot boat from Wisconsin to Florida a few years back. Used a different vehicle than his normal tow vehicle. The hitch was too high in his case. Bucked all the way down. Had to get a new rear end when he returned to Wisconsin.
posted 10-21-2004 07:57 AM ET (US)
Let me throw in another vote for increasing the tongue weight to stop the sway. I personally wouldn't have much less than 10% tongue weight, but agree that moving the axle back is the appropriate way if the bunks already extend to the transom. That, and the proper drop bar to level the trailer, will help reduce the porpoising.
Also double-check tire pressures and make sure the truck shocks are in good condition. This will be even more important when you add the camper. Before doing so, I'd add a rear sway bar if you don't have one already, and consider a larger front sway bar. I'd also consider moving up to Load Range E tires on the truck if you don't have them already.
The high center of gravity of a camper is going to make the truck respond to and feed sway. You can't afford to have it happen with the camper.
posted 10-21-2004 08:03 AM ET (US)
Sidewall flex in under inflated tires can cause fishtaiing but usually in heavier trailers. I run all three of my trailers at their max tire pressure to eliminate this. My 170 Caravan combo tows just fine with either a full size (my truck) or mini truck (wifes truck). I've even done a 600 mile highway trip and had no problems.
posted 10-21-2004 09:08 AM ET (US)
You do not need a load balancing hitch to haul a Montauk. Sway bar is a good idea, but not absolutely necessary. Biggest things are tongue weight and tire pressure; Moe's suggestion of 10% target is a good one, and you should always have the tire pressure set to max when cold, and check regularly. Lowering or raising the tongue so the trailer rides level would be next on my list.
posted 10-21-2004 12:13 PM ET (US)
Thanks for the suggestions. This gives me a list of things to check. I've been meaning to measure the tongue weight with a bathroom scale but my wife has this fancy digital scale with a glass top that is not suitable for that.
Thanks for the suggestions on upgrading the truck's suspension. I've been checking the truck camper forums and have been amazed at the number of aftermarket parts there are for upgrading the suspension. Of course, most people that use these have rigs that weigh three or four times what mine will. I purposely chose the lightest camper I could find to try to keep the rig under GVWR. I will try it out and then decide whether I need suspension upgrades or a new truck altogether.
posted 10-21-2004 03:08 PM ET (US)
I also have a Montauk 170 with the 90 4-stroke and the factory Karavan trailer. I have never had a bit of fishtailing or hobby horsing. I do not have a sway bar or a load leveling hitch.
A couple of thoughts:
posted 10-21-2004 05:50 PM ET (US)
Here's a little about that camper, I have a 2003 Siverado 2500 3/4 ton truck and have a 6.5 foot bed and a Sun-lite pop-up camper to match, mine is a light weight camper, about 1400lbs, I'm allowed to go to 1900lbs. as per the sticker in the glove box and owners manual. With this set-up I wouldn't even worry about towing a MOntauk behind it, I did have a 89 Newport with a 90hp Johnson, the truck hardly knew it was there and no sway, set up your hitch height, and tongue weight and you should be fine. That truck camper will probably require a hitch extension also! So you know, I'm planning on trying out my camper in the truck while towing a 20ft Revenge, I think it'll be fine but will be getting close to what I would consider my limit, if you are using a half-ton truck , that camper is going to make a real big difference, and remember the weight of the camper has to include fluids and supplies and water, that's about 400lbs. on mine, actual camper weight is around 1050 lbs.........................Jack
posted 10-21-2004 10:42 PM ET (US)
Tongue weight is the key to any fish tailering problem.And you must concider how you have the load in the boat .A full fuel load and a large cooler with ice makes a big difference and must be entered into the equation when you figure the tongue weight.Sway bars and equallizer weight hitches are band aid approaches to having the proper correct complete tow package. Think of a tow package as a arrow in flight,the weight needs to be in the head of the arrow to produce a stable flight.Same with a tow vehicle and trailer.
posted 10-26-2004 01:28 PM ET (US)
How about just a simple "over-steering" problem. When I tote my 13' w/ a Silveraldo, I can fish tale if I "oversteer". Also, check the bunks on the trailer and make sure the boat is positioned correctly o the trailer.
posted 10-28-2004 02:35 PM ET (US)
You might also look and see if you trucks struts, shocks or whatever are old and in need of replacing. If so get osmthing like Rancho RS 5000s or better yet Bilsteins or at least something with good damping and sized for your trucks weight. J
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