FULL-THROTTLE
New Member
I am just wondering what is the top speed of your challenger, I only get 46 MPH, all stock engines, 1998, I expected more????
Thanks
Thanks
your Challenger top speed
- Thread starter FULL-THROTTLE
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I had my 96 twin engine Speedster on the water this weekend and I could only get 46MPH too. However, both my motors are bored out and my boat is probably lighter than yours too. I figure I should be in the 56MPH range on the speedo and GPS around 51MPH
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robin savell lloyd
Active Member
I do not believe it maters on how much horse power you have or how much torque your engine can deliver. let me try and explain this cazy thinking. If your boat came stock with lets say 2 rotex engines in them that were 110 hp each and your able to get rpms up around 7000 to 8000 and you have a impeller with a 15 - 20 pitch. I do not thank it would matter if you were able to get 200 hp out of each engine with the same rpms and the same prop your top speed should remain the same. I belive you would need too call someone like dave at impros. he is a expert at this. If Iam not mistaken you probly can get 10 more mph out of a twin engine boat without having to bad of cavitation. If any one would know dave at impros should.:cheers:
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Gunsrunner
New Member
G'day guy's,
It's all to do with,
1) Horsepower, the more hp you have the more potential to move more water through the jet pump(more thrust).
2) Impeller pitch, the more HP the stronger the pitch you can use and the more water you move.
3) Revolutions, with more HP and Pitch and keep the revs at the maxiumum, the more water you move.
4) Cavitation, the less cavitation also means more water through the jet pump.
So, make as much HP as possible, then re-pitch your impeller to hit the maximum revs and plug any gaps and fill any holes and smooth any rough spots in the jet pump to stop cavitation.
This will give you the maximum speed avaliable.:cheers:
It's all to do with,
1) Horsepower, the more hp you have the more potential to move more water through the jet pump(more thrust).
2) Impeller pitch, the more HP the stronger the pitch you can use and the more water you move.
3) Revolutions, with more HP and Pitch and keep the revs at the maxiumum, the more water you move.
4) Cavitation, the less cavitation also means more water through the jet pump.
So, make as much HP as possible, then re-pitch your impeller to hit the maximum revs and plug any gaps and fill any holes and smooth any rough spots in the jet pump to stop cavitation.
This will give you the maximum speed avaliable.:cheers:
calgary seadooer
New Member
calgary seadooer dissapointed
well was responding to ur thread....i have a 97 challenger with a single engine i'm only getting 35mph and was expecting more....i cant even pull a single tuber and apparently the guy i bought the boat from didnt know anything about motors so he got a new "crate " engine put in it....i was expecting the boat to out perform my older glascon outboard (115hp merc)but it doesnt come close?i changed the plugs and new batt so far and have been reading up in the forums about the rave valves but the motor is just new last yr in july?????could you offer any advice?
well was responding to ur thread....i have a 97 challenger with a single engine i'm only getting 35mph and was expecting more....i cant even pull a single tuber and apparently the guy i bought the boat from didnt know anything about motors so he got a new "crate " engine put in it....i was expecting the boat to out perform my older glascon outboard (115hp merc)but it doesnt come close?i changed the plugs and new batt so far and have been reading up in the forums about the rave valves but the motor is just new last yr in july?????could you offer any advice?
I own a 1997 Challenger with a single 110 hp 787 model seadoo. It will do 50 MPH with me,(175#) and 1/2 tank of fuel. It could be the sync of the carbs or maybe it isn't getting full throttle. I have seen some jet boats only getting to 40mph because the throttle cables weren't adjusted correctly.
Give it a look over.
Karl
Give it a look over.
Karl
calgary seadooer
New Member
hey karl youve been pretty helpful in regards to the thread i left here.....um i ve actually clened the rave valves and put a new impellor and wear ring on...now i am leaning towards the carbs or like you say throttle cable.....question is how would i know where the proper setting would be?????
Here's what I do...with the carb cover off...not running of coarse...be sure the throttle comes back to idle position...look to see if there is any play in cable at carbs. Now put in gear and push throttle all the way forward. Does the throttle linkage travel like 99% forward to WOT,(wide open position)? I adjust so there is a small amount of play in cable at idle so it will snap closed all the way for idle...and adjust the cable so it will pull the throttle linkage 99% full throttle. If needed I pull the controll handles out to make an adjustment there too to gain all I can. The Idle position at carbs needs a small amout of slack in cable only to "snap" to idle.(not taunt) Take your time to get it right. I gained like 5 mph after.
More speed is all about the details.
Karl
More speed is all about the details.
Karl
robin savell lloyd
Active Member
If the rpms are very close to rev limiter there is not much more you can excpect from the motor as far as top speed goes. You can do like alot of others and report your top speed from the factory speedometer or have a 30 mph wind at your back. Your boat is 3 times as heavy as a pwc and you are 10 mph slower that seems about right to me as a mater of fact I think you are doing very good. This is a single engine boat right?
Challenger Top Speed
I have a '99 18' Challenger with twin 110's and at altitude with two onboard get 46-47mph on speedo. Would like to see more speed but have not found any fixes, most say you are limited by the size of the boat and jets/impellers.
Anyone know of reasonable cost upgrades to get into the mid 50's? Boat seems to limit out at 7000 rpm's is this standard?
Thanks,
I have a '99 18' Challenger with twin 110's and at altitude with two onboard get 46-47mph on speedo. Would like to see more speed but have not found any fixes, most say you are limited by the size of the boat and jets/impellers.
Anyone know of reasonable cost upgrades to get into the mid 50's? Boat seems to limit out at 7000 rpm's is this standard?
Thanks,
In the 7000 range is good...I think 7300 is exact. Check the carbs for FULL Throttle opening. Re read my post #9 in this thread.
Karl
Karl
calgary seadooer
New Member
yes robin its a single engine boat it just seems as tho its starved for something like air or fuel?any suggestions would be great....i still wanna be able to tow a skier behind it....the previous owner said he had it up to 70km an hr?and its a new crate motor in there so it must be something...
SeadooBOB Square Pants
New Member
96 Speedster
My 1996 two weeks ago clocked 46-48mph and my compression mean is about 120. That is actually less than what the motors come stock. Are your carbs tuned really well? 70km is only 43 mph it should be hitting that, I would think.
My 1996 two weeks ago clocked 46-48mph and my compression mean is about 120. That is actually less than what the motors come stock. Are your carbs tuned really well? 70km is only 43 mph it should be hitting that, I would think.
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robin savell lloyd
Active Member
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I now own this boat, and with me and the wife in it and a nearly full tank, and the bimini top up, we maxed out around 47 mph (gps). I am 210 lbs.
So, whatever Karl did was a good thing...:hurray:
epicboater
New Member
whats up
I have a 1996 sea doo sportster, single 85 hp. Last weekend I was rasing down the lake in little choppy water and my gps said I was doing, 48 mph and my speedo said I was doing 45 pmh. I am a big guy at 350 lb, Later in the day I was tubing so there was me my wife so around 500 lbs, plus the tuber a 14 year old boy who is about 110 and I was able to get up to 40 mph on my speedo. then later on with my dog in the boat I was not able to get it to plain it just would not get fully out of the water, got real pissed, got my goggles and went for a swim under the boat, and what did I find in the water intake a stick, pulled it out checked everything over, then went back out on the lake, problem fixed, jumped out of the water and got 50 on the speedo, by this time I had a less then a half tank. Like my cars I just tinker with it every weekend before taking out. However was supprised that a small stick could reduse the water thrust that much. I just love doing dohnuts at full speed and then just crank the wheel. I also just love jumping waves, what a rush.
I have a 1996 sea doo sportster, single 85 hp. Last weekend I was rasing down the lake in little choppy water and my gps said I was doing, 48 mph and my speedo said I was doing 45 pmh. I am a big guy at 350 lb, Later in the day I was tubing so there was me my wife so around 500 lbs, plus the tuber a 14 year old boy who is about 110 and I was able to get up to 40 mph on my speedo. then later on with my dog in the boat I was not able to get it to plain it just would not get fully out of the water, got real pissed, got my goggles and went for a swim under the boat, and what did I find in the water intake a stick, pulled it out checked everything over, then went back out on the lake, problem fixed, jumped out of the water and got 50 on the speedo, by this time I had a less then a half tank. Like my cars I just tinker with it every weekend before taking out. However was supprised that a small stick could reduse the water thrust that much. I just love doing dohnuts at full speed and then just crank the wheel. I also just love jumping waves, what a rush.
brickslayer
New Member
'97 Challenger 1800
My 97 Challenger 1800 will run consistently at 55 with 4 people in the boat, and I have seen 60 with just me and my wife. Not sure if the impellers are stock because I am the third owner......judging by the condition of the rest of the boat when I bought it though I would seriously doubt that anyone ever changed anything that didn't absolutely need it.
My 97 Challenger 1800 will run consistently at 55 with 4 people in the boat, and I have seen 60 with just me and my wife. Not sure if the impellers are stock because I am the third owner......judging by the condition of the rest of the boat when I bought it though I would seriously doubt that anyone ever changed anything that didn't absolutely need it.
About the Cables
When adjusting the throttle cables, you want to make sure at full throttle, the cable does not fully rotate the carb lever... there should be 1/64 inch clearance between the stopper and the fully-deflected cable cam.
The reason is, most people hold their throttle levers with a death grip when running at full speed. This is what causes cable stretch. Next problem is, if the cable cam is snugged against the carb, you are putting a lot of pressure on the entire throttle train - and may break the carb, cable or intake manifold when jumping a wave. So tighten up your friction nuts under the throttle levers (see service manual its tricky) and dont hold onto the throttle levers. Another reason, the levers are made of cheap pot metal and do break.. and no replacements are available.
ALso, remove your air boxes, push both throttle levers full forward and measure the throttle plate deflection angle. You may find one that does not fully open.
Dont confuse the choke plate with the throttle plate.
When adjusting the throttle cables, you want to make sure at full throttle, the cable does not fully rotate the carb lever... there should be 1/64 inch clearance between the stopper and the fully-deflected cable cam.
The reason is, most people hold their throttle levers with a death grip when running at full speed. This is what causes cable stretch. Next problem is, if the cable cam is snugged against the carb, you are putting a lot of pressure on the entire throttle train - and may break the carb, cable or intake manifold when jumping a wave. So tighten up your friction nuts under the throttle levers (see service manual its tricky) and dont hold onto the throttle levers. Another reason, the levers are made of cheap pot metal and do break.. and no replacements are available.
ALso, remove your air boxes, push both throttle levers full forward and measure the throttle plate deflection angle. You may find one that does not fully open.
Dont confuse the choke plate with the throttle plate.
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