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| GatorTail help https://mudmotortalk.com/mmt_v2/viewtopic.php?f=3&t=75225 |
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| Author: | Runninskinny86 [ Mon Aug 03, 2020 3:48 pm ] |
| Post subject: | GatorTail help |
I recently bought a 23hp Gatortail with some aftermarket mods.(carb, exhaust, cam.) all the small stuff to add a little extra power. After building my transom up to 22" ( 1" higher than I was shooting for) I mounted it up and test ran it on my '98 xpress 1648. It took a lot to make it get up and on top of the water. It was like the motor was bogged down until I could get the prop half out of the water. The top speed I can get out of it is only 27 with an empty boat. Problem 2 It pulls like a mother to the left. The whole time the arm is trying to push you out of the boat. The lower stump guard has the last half inch bent at about a 30 degree angle to the port side so that should be helping but it doesn't seem to be enough. I've heard that moving the motor over on the transom can help it steer easier but I'm not sure if that will help in this situation. Thanks for the help and I can post pics if they would help. Just for comparison I had a 23 hp homemade surface drive on it previously and the boat would jump right on plane and run 27 just fine with it. |
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| Author: | Will C [ Wed Aug 05, 2020 3:10 am ] |
| Post subject: | Re: GatorTail help |
Its easy to build a 23 that has no low end torque. Big carb adapter, big cam, big heads. Check the basics, valves set right, leakdown, whats the actual compression number. Plugs look like they are running decent. U may need to prop down or gear down. On the tiller torque, u have the right ideas. Maybe try a different prop first. The prepped props with sharper edges seem to push less |
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| Author: | Russ [ Wed Aug 05, 2020 6:20 am ] |
| Post subject: | Re: GatorTail help |
Also, don't forget to check lower unit in relation to bottom of boat. If your motor is sitting too high, you have to trim down too far to get the prop to bite, which leads to the wrong angle, which leads to that tiller torque you say is so bad. That won't solve the fact your motor doesn't have the ass you think it should, but it'll help you be able to get the propshaft angle of attack in a better spot for trim to eliminate tiller torque. Check all fuel connections. May have an air leak somewhere. Since the engine sounds like it's bogging, change your fuel. We used to have that issue with a longtail that would behave fine until it was in the "work harder" stage getting the boat out of the hole and up to speed. Then, behavior was exactly what you describe. Everytime that happened, we'd all look at my father because he'd filled up the boat fuel tank again out of his home stash of gas cans. Those cans always seemed to have water in the gas. It was clockwork. #CFFITR #mudmotor>physics |
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| Author: | dguidry [ Wed Aug 05, 2020 7:17 am ] |
| Post subject: | Re: GatorTail help |
Buddy of mine boought a 25 aspirated carb big block GatorTail to comply with Texas WMA restrictions on motor sizes. It was a slow assed hog with a load, barely got on step. I referred him to a friend who installed cam, crankshaft, decked heads, valve job, rockers, rods, and Mikuni Carb. Runs 33 mph now with 3 people and gets on step very quickly on an Uncle J custom.. $4,000 modification. An EFI 40XD GatorTail would have cost only $1000 more at the time, but with the restrictions he could not have used it in Texas. Now he can hunt Southeast Texas and Louisiana. |
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| Author: | Runninskinny86 [ Wed Aug 05, 2020 1:21 pm ] |
| Post subject: | Re: GatorTail help |
thanks for the replies. my engine is set @ 22"s on an 18 degree transom. from what I've read the sweet spot is 21" on a 20 degree angle. I don't know if that's enough to throw it off or not. I can cut the transom down an inch pretty easy and I'm sure I could add some wedges to add the extra angle. As for the motor, since I really don't know what the previous guy put in the motor all I can do is test and make sure everything is adjusted correctly and I'll probably go ahead and buy new plugs. As for the prop I think it's a hammered prop. |
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| Author: | Runninskinny86 [ Wed Aug 05, 2020 1:32 pm ] |
| Post subject: | Re: GatorTail help |
Here are some pictures for reference. The motor is in the up most position |
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| Author: | Runninskinny86 [ Wed Aug 05, 2020 1:49 pm ] |
| Post subject: | Re: GatorTail help |
| Author: | Russ [ Wed Aug 05, 2020 1:57 pm ] |
| Post subject: | Re: GatorTail help |
The height and angle are functional enough the torque shouldn't be that bad. Scoot the motor over. The rest of your issue isn't due to motor height or angle. It's mechanical. Compression test is quick and start pointing towards something give you a bit warmer fuzzy about the internals, at least. #CFFITR #mudmotor>physics |
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| Author: | Runninskinny86 [ Wed Aug 05, 2020 2:10 pm ] |
| Post subject: | Re: GatorTail help |
| Author: | Russ [ Wed Aug 05, 2020 2:18 pm ] |
| Post subject: | Re: GatorTail help |
Yeah, but I doubt it'll help torque a lot. Motor trim, prop dynamics, and skeg angle are gonna have the largest effect. #CFFITR #mudmotor>physics |
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| Author: | Runninskinny86 [ Wed Aug 05, 2020 6:30 pm ] |
| Post subject: | Re: GatorTail help |
I had 105 on both cylinders so I think I’m good there. Plugs were pretty black so I’m just gonna go buy some new ones. I have a cousin that does small engine repair so I’m gonna let him do some tuning on the carb to make sure it’s right. Maybe look into props. As far as the torque would it make sense to bend the skegg further back instead of just the inch I show pictured?? |
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| Author: | Russ [ Wed Aug 05, 2020 7:04 pm ] |
| Post subject: | Re: GatorTail help |
When you compression tested, were you holding the throttle wide open? And 105 seems low. Try again doing that, and see what the psi is supposed to be on that engine. Yes on the skeg. Mine was bent all the way to the cut. It'll make a difference. #CFFITR #mudmotor>physics |
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| Author: | Runninskinny86 [ Wed Aug 05, 2020 7:28 pm ] |
| Post subject: | Re: GatorTail help |
| Author: | Russ [ Wed Aug 05, 2020 8:40 pm ] |
| Post subject: | Re: GatorTail help |
A compression test with the throttle closed doesnt tell you what the compression on that engine is. A briggs 35 with the throttle closed even with compression over 190 will show 95 psi. A stock engine should be around 150, but it'll show 90ish without opening the throttle. Even an engine with 1 cylinder at 110 and the other at 150 could show the same compression without opening the throttle. #CFFITR #mudmotor>physics |
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| Author: | Runninskinny86 [ Thu Aug 06, 2020 2:00 pm ] |
| Post subject: | Re: GatorTail help |
| Author: | Runninskinny86 [ Tue Aug 18, 2020 6:41 pm ] |
| Post subject: | Re: GatorTail help |
Update I check my plugs and they were black. So I went and bought a set of new ones. Boat ran better as far as getting up on plane at first. After a little while of running I noticed the power going away. After stopping it wouldn’t jump on plane and took forever to get it there. Once I got home I pulled the plugs. Black again. Would this be a carb adjustment issue? I’m running a mikuni carb. Also I added some more bend to the skeg and the motor runs perfectly straight now. Getting a little splash in the boat but I can deal with that |
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| Author: | Russ [ Tue Aug 18, 2020 7:21 pm ] |
| Post subject: | Re: GatorTail help |
So, at idle it could be rich and causing them to look black when you pull them. That's an indication mixture/jetting at idle isn't just right. But that doesn't mean that's what's causing your issue. Jetting at mid and full throttle are what you need to know. If you cut ignition while at full throttle after running for a few mins, that'll tell you more with plug color. Also, black plugs doesn't mean they're bad. A bit of sandpaper and a toothbrush can clean them up. I may have glossed over it, but what did the leakdown test show? Any air getting into the fuel lines? #CFFITR #mudmotor>physics |
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| Author: | Will C [ Wed Aug 19, 2020 12:02 am ] |
| Post subject: | Re: GatorTail help |
May need to drop needle down 1 to 2 steps |
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| Author: | Runninskinny86 [ Wed Aug 19, 2020 5:25 am ] |
| Post subject: | Re: GatorTail help |
| Author: | Runninskinny86 [ Wed Aug 19, 2020 5:27 am ] |
| Post subject: | Re: GatorTail help |
| Author: | Runninskinny86 [ Wed Aug 19, 2020 5:28 pm ] |
| Post subject: | Re: GatorTail help |
| Author: | Russ [ Wed Aug 19, 2020 5:44 pm ] |
| Post subject: | Re: GatorTail help |
Pm sent #CFFITR #mudmotor>physics |
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