Really dumb trolling valve question

Other than having used them on other boats and understanding the basic functionality of trolling valves, I don't know much about the actual mechanics of them.

I am looking at a newer boat with a 490HP Cummins in it. The problem is, it DOES NOT have a trolling valve which will pretty much be a necessity for trolling for stripped bass.

My question is, can a trolling valve be added to the existing transmission or would I have to change the entire transmission out?

I have read some about the electronic trolling valves with the interlocks that keep you from accidentally wiping out the transmission by kicking out the trolling valve once the RPMs reach a certain point. I would prefer this option if available.

I didn't get the make/model of the transmission - I am waiting on the guy to get back to me with that info.

If an add-on trolling valve is available, could anyone provide a ball park estimate on installation (part+labor)?

Thanks,
Tawn

 

You can defiantly add it. I put a mechanical valve on a brand new order and it was around $1000 for the valve installed. I couldn't tell you what it would cost for a valve to be installed on a used gear but it can defiantly be done.

 

Thank you for the feedback! The deal may very well come down to whether or not I can add the trolling valve (both engineering wise and financially).

 

Where are you located? One of the local cummins guys can most likely easily answer your questions

 

Maryland - Chesapeake Bay.

The minute the seller calls me back with the exact make & model of the transmission, I will be calling the local Cummins shop. I'm just a little inpatient.

 

I tried to put one on my twin disc 5114 when I converted it to electronic shift and it was a nightmare to add the troll valve option. $1800 for electric shift conversion and $3500 to add the troll valve. I use Palmer Johnson in SoCal and they did a pretty good job researching the conversion with twin disc. I can email the procedure & part list from twin disc if you're interested.

 

Thanks guys.

The seller says it's a ZF 2:1 or 1.9:1 reduction ratio transmission. He will get me the actual model number / serial number in the next day or two.

 

thought ZF actually said they would back up any trolling valve THEY put in THEIR transmission. fwiw

 

You may be able to figure out what ZF model it has if you google the engine model. There is usually a list of compatible transmissions in the technical data.

I would expect the Cummins guys will tell you to call a ZF dealer.

BTW - This is not a dumb question. Better to find out upfront what the cost is.

 

If you have a 490 Cummins with a ZF gear you most likely have a ZF 280, 285 or if the application is spec'ed more severe than recreational you'll get a 301, 325 or 350 series. Trolling valves both mechanical and electronic are easily retrofitted. Get the gear model, serial and part number and call the main office for North America in Mirramar Florida. They will give you price and availability and a local dealer. If you have electronic controls it is possible to program the engine not to exceed a set RPM in troll. Mechanically managed engines will only show a warning light at the helm if equipped, and it's easy to run them up in troll and smoke the gear. Troll works by reducing the clutch apply pressure down from say 350 PSI to close to zero giving you slip that reduces shaft speed. With the gear oil redirected over the clutches for cooling and only an input speed at idle there is no problem. Above that the heat is too much and you can literally see the gear change color before your eyes. One charter captain on whose boat I replaced the gear from running it up in troll simply bought a door hinge and mounted it at the control. When in troll it had to be flipped in front of the throttle blocking it from being advanced. Flipped the other way you could throttle up but not advance the troll lever. Simple genius.

 

Thank you, thank you, thank you for the info - I will have the exact gear info this weekend - I suspect it has either the 301, 325 or 350 series gears. The gentleman selling the boat is the original owner. He had it built as a charter boat and everything else is done pretty much first class and heavy duty. It has mechanical Kobelt controls - I am definitely interested in rigging up something to prevent a simple mistake from wiping out the gears, the hinge idea is pure genius!

Would you be willing to give me a ballpark, guess-ti-mate on what I might expect to pay to have one put on the boat (part, labor & ancillaries) ?

I really appreciate the help.

Thanks again.

 

This is a good thread. I have a ZF 304A and want to put a trolling valve on this winter. Good info!

 

For what its worth- 1000 bucks is the going rate for a ZF 280 electronic troll valve, just bought one. But then you need a way to control it, which can either be expensive where you buy a fancy marine specific handle unit, or go to the proportional valve mfg (in ZF's case it is Hydraforce) and get one of their proportional valve controllers, then you can install a simple on off switch and speed pot of your choice, which helps keep the helm less cluttered. Electronic engine with troll rpm limiting is a real nice safety feature. Cummins vessel view has that.

 

I think that Ol Gilnetter is correct for both parts price and advice. In the ZF lineup the series of transmissions we are talking about are the ones above the Hurth legacy gears (those use ATF such as the 45, 63, 80 instead of SAE 30 oil and have a different shift control). Except for the ZF 220 which has it's control head integral to the back case bearing cover, the remaining transmissions in the size range we're talking about use either the MB or EB 15 or MB, EB 30 control blocks. The M or E denotes whether it is mechanical or electronic shift and the number whether the spin on filter screws to the transmission case or to a filter head directly on the control block. This is the larger of the two blocks to make room for the filter adapter. Either way they are square aluminum blocks with a removable steel plate that is replaced by the troll valve so the same valve fits across a wide range of gears. 4 bolts on the control block and the supplied O-rings and it's on. No going into the gear itself. But like he said the real work begins by rigging the control. If you have mechanical controls you run a Morse style cable to a lever. If you have compatible electronic controls you program it in. Or like Ol Gilnetter said those use Hydraforce valves and a potentiometer / control could be rigged up. So labor would have to be estimated on a case by case basis. No matter what system goes in, it's a good idea to monitor the gear with a pressure gauge even if it's only a temporary one screwed right to the control block. ZF uses Bar (1 Bar is about 14.5 PSI) and the spec is right on the case tag. Sometimes the troll valve can bring the application pressure all the way to zero, but most idle speed troll works well between 20 to 80 PSI.

 

Thanks for all the help guys. Adding a trolling valve is within our budget. My partner and I signed the sales contract and put a deposit down on a gorgeous, barely used 46 Markley.

490HP Cummins with 804 hours on it.

Certified for 17+2 under the new rules.

 

Nice. Looks new and congratulations. With a Markley you must be down closer to Chortle and I. I did a lot of work in their yard and they do a nice job.

 

great boat! Congrats! BTW: On your COI 17 plus 2 crew, what did you mean under NEW RULES?? thanks

 

Not exactly sure where you are but you can call Alan Hall over at Anchor Yacht Basin on the South River. They are Cummins and ZF dealers. Alan is a very knowledgeable guy and I am sure he could steer you in the right direction...good luck...nice find !!!

 

thats a cracker

 

Evidently they (USCG) changed their calculations when doing the stability test. It used to use something like 145lbs as the weight of an average person and upped it to something like 165lbs. Not completely sure of the exact details but basically they upped the weight they were using for the "average" passenger in the calculations.