Hey every one i have a 1036 g3 jon boat with a briggs animal on a kkk longtail, I am running a 6" prop, with two people in my boat i hit rev limiter and max at 9mph, am i experiencing prop cavitation or should i start going up in prop size?

It's probably cavitating because those Thai long tails don't have a cavitation plate to hold the prop under water. Try pulling up on the tiller handle to force the prop under water. It's gonna wear you out though.

1036? Holy shit.
Longtails typically don't do good speed-wise on short boats.
Why do you think it's cavitating?



Sent from my iPhone using Tapatalk

i see lots of foaming water, and lifting the handle does not do much, i only run on a small river and like to go up creeks where a bigger boat wont go. by myself in the boat it feels like 20 mph

The Thai longtails have too long of a shaft to add a cavitation plate. In order for the cav plate to hook on the shaft housing and be above the prop blades the angle would be too steep for the shaft length and the prop would be 2 or 3 feet under water.

I saw this in another forum. I am new to this forum so it will take me a while to figure out how to post pics. I'll try and post a pic of the planing tab mentioned below:
There are several factors that can cause a Thai longtail to climb out of the water. The
following checklist of remedies should be followed in order;
1. Engine base upside down – a commonly made mistake. The engine can be mounted on
the base two ways, but there is only one correct way. If your engine is mounted on the base
correctly the heads of the bolts that hold the tiller handle in the rings should be pointed
upward. If the heads of the tiller retaining bolts are pointed downward, the engine base is
upside down. Flipping it over and remounting the engine correctly will result in a significant
improvement in performance and handling.
2. Running an 85" shaft on a boat with a transom taller than 16" will create a steep shaft angle
that will cause the shaft to ride up out of the water. We don’t recommend running a longtail on
a boat with a 20” transom, but if it’s the only boat you have then you will need a 100” shaft.
3. The transom bracket should normally be mounted with the hole for the gimble shaft
positioned on the outside of the transom.
4. Balance can also affect performance. Because not all engines weigh the same, the Thai
longtail has adjustment holes on the side of the engine base. Moving the engine base back
will create additional tail weight. Reposition the engine base one set of mounting holes at a
time. Test run the longtail and reposition if necessary.
5. Running too large of a propeller for the engine/hull can also cause the shaft to ride up out
of the water. Over-propping is the #1 mistake we see. Bigger is not always better. Try a
smaller prop.
6. Running a Thai longtail on too wide of a hull (anything over 48" measured across the
bottom is too wide) can cause the shaft to climb out of the water. Unlike all other longtails, the
Thai longtail prop is surface piercing and designed to run in the crest of the two wakes where
they meet behind the boat. The wider the hull, the further behind the boat the two wakes
meet. Therefore, a wider hull will require a longer shaft to reach the crest of the wakes. If the
shaft is running in the trough located forward of the wakes, it will be very hard to control.
Narrow hulls are better for longtails.
7. If followed correctly, steps 16 will remedy the vast majority of handling and performance
issues encountered. However, we’ve seen a few boat hulls that just don’t play well with
longtails. ONLY if steps 16 have not worked, do we recommend a planing tab as the final
solution. We can send you a couple pictures of a simple planing tab. The tab is only 1.5" wide
and 3" in overall length. You can make one easily out of 1/8" steel using a metal bandsaw,
and spot weld it to the skeg at the angle displayed on the template and in the picture. The tab
can be adjusted by bending the tail up or down. Whenever we encounter a longtail that is
difficult to control on some western style hulls, this tab does the trick.
Once you have it dialed in, your longtail should operate with little effort.

I saw this list in another forum. I'll try and find a pic of the planing tab and post it.

There are several factors that can cause a Thai longtail to climb out of the water. The
following checklist of remedies should be followed in order;
1. Engine base upside down – a commonly made mistake. The engine can be mounted on
the base two ways, but there is only one correct way. If your engine is mounted on the base
correctly the heads of the bolts that hold the tiller handle in the rings should be pointed
upward. If the heads of the tiller retaining bolts are pointed downward, the engine base is
upside down. Flipping it over and remounting the engine correctly will result in a significant
improvement in performance and handling.
2. Running an 85" shaft on a boat with a transom taller than 16" will create a steep shaft angle
that will cause the shaft to ride up out of the water. We don’t recommend running a longtail on
a boat with a 20” transom, but if it’s the only boat you have then you will need a 100” shaft.
3. The transom bracket should normally be mounted with the hole for the gimble shaft
positioned on the outside of the transom.
4. Balance can also affect performance. Because not all engines weigh the same, the Thai
longtail has adjustment holes on the side of the engine base. Moving the engine base back
will create additional tail weight. Reposition the engine base one set of mounting holes at a
time. Test run the longtail and reposition if necessary.
5. Running too large of a propeller for the engine/hull can also cause the shaft to ride up out
of the water. Over-propping is the #1 mistake we see. Bigger is not always better. Try a
smaller prop.
6. Running a Thai longtail on too wide of a hull (anything over 48" measured across the
bottom is too wide) can cause the shaft to climb out of the water. Unlike all other longtails, the
Thai longtail prop is surface piercing and designed to run in the crest of the two wakes where
they meet behind the boat. The wider the hull, the further behind the boat the two wakes
meet. Therefore, a wider hull will require a longer shaft to reach the crest of the wakes. If the
shaft is running in the trough located forward of the wakes, it will be very hard to control.
Narrow hulls are better for longtails.
7. If followed correctly, steps 16 will remedy the vast majority of handling and performance
issues encountered. However, we’ve seen a few boat hulls that just don’t play well with
longtails. ONLY if steps 16 have not worked, do we recommend a planing tab as the final
solution. We can send you a couple pictures of a simple planing tab. The tab is only 1.5" wide
and 3" in overall length. You can make one easily out of 1/8" steel using a metal bandsaw,
and spot weld it to the skeg at the angle displayed on the template and in the picture. The tab
can be adjusted by bending the tail up or down. Whenever we encounter a longtail that is
difficult to control on some western style hulls, this tab does the trick.
Once you have it dialed in, your longtail should operate with little effort.

A fella that races carts swears he builds them to turn 8 grand and make 60 hp.

8000 rpms? Yea. 60hp? Not so sure about that..

Animal motors have been known to turn up 11000 to even 13000 rpms in kart racing and they still don't put out those hp numbers people claim alot of shit that don't exist. At 8000 rpms on a dyno they usually r rite around 30 hp the hp will actually drop off on the dyno after that but while the kart has momentum it still rolls faster at 11000 rpms

A list that was sent to me:
There are several factors that can cause a Thai longtail to climb out of the water. The
following checklist of remedies should be followed in order;
1. Engine base upside down – a commonly made mistake. The engine can be mounted on
the base two ways, but there is only one correct way. If your engine is mounted on the base
correctly the heads of the bolts that hold the tiller handle in the rings should be pointed
upward. If the heads of the tiller retaining bolts are pointed downward, the engine base is
upside down. Flipping it over and remounting the engine correctly will result in a significant
improvement in performance and handling.
2. Running an 85" shaft on a boat with a transom taller than 16" will create a steep shaft angle
that will cause the shaft to ride up out of the water. We don’t recommend running a longtail on
a boat with a 20” transom, but if it’s the only boat you have then you will need a 100” shaft.
3. The transom bracket should normally be mounted with the hole for the gimble shaft
positioned on the outside of the transom.
4. Balance can also affect performance. Because not all engines weigh the same, the Thai
longtail has adjustment holes on the side of the engine base. Moving the engine base back
will create additional tail weight. Reposition the engine base one set of mounting holes at a
time. Test run the longtail and reposition if necessary.
5. Running too large of a propeller for the engine/hull can also cause the shaft to ride up out
of the water. Over-propping is the #1 mistake we see. Bigger is not always better. Try a
smaller prop.
6. Running a Thai longtail on too wide of a hull (anything over 48" measured across the
bottom is too wide) can cause the shaft to climb out of the water. Unlike all other longtails, the
Thai longtail prop is surface piercing and designed to run in the crest of the two wakes where
they meet behind the boat. The wider the hull, the further behind the boat the two wakes
meet. Therefore, a wider hull will require a longer shaft to reach the crest of the wakes. If the
shaft is running in the trough located forward of the wakes, it will be very hard to control.
Narrow hulls are better for longtails.
7. If followed correctly, steps 16 will remedy the vast majority of handling and performance
issues encountered. However, we’ve seen a few boat hulls that just don’t play well with
longtails. ONLY if steps 16 have not worked, do we recommend a planing tab as the final
solution. We can send you a couple pictures of a simple planing tab. The tab is only 1.5" wide
and 3" in overall length. You can make one easily out of 1/8" steel using a metal bandsaw,
and spot weld it to the skeg at the angle displayed on the template and in the picture. The tab
can be adjusted by bending the tail up or down. Whenever we encounter a longtail that is
difficult to control on some western style hulls, this tab does the trick.
Once you have it dialed in, your longtail should operate with little effort.