cigarette top gun 38 virgin questions
 

Hi all
My boss just got a great condition 1999 Top Gun 38 with BDS super charger, I believe they are 596cc blocks with 3A drives, engine pic and others here http://www.dropbox.com/home/boat?pre...6_1_XLARGE.jpg

It came with 4 blade cleaver props that where 33's we had trouble at low speed with the engines stalling as soon as put in gear. the boat was used on an event that had to be used at slow speed so our mechanic swapped the props to 5 blade 31's Herings to help the stalling a little. we still have to trim up close to out of the water and give it a bit of throttle to get it going. So my question is is this normal to stall at idle with no throttle? Our mechanic played with the carbies and cleaned them said they where ok. The boat was a freshwater boat originally and we are in salt water.

We are seeing a top speed of 70mph at around 6000rpm with the 31 Herings. I would have thought it would be quicker than than that. Comments.

Crowfoot.

Link to photos doesn't work.

if those motors are putting out at least 650hp you should be seeing 75mph and up from there.

Weird both motors dies when you put them into gear. I'd say its a carb issue when load is put on the motor as it's dropped into drive but not on BOTH motors. Pitch of the prop still too big and causing too much load still?

Also, doesn't make much sense you have to trim the drives out like that, not to mention it's not good for the drives to put load on them trimmed out that far.

596 cc x 2 =1196 cc divided by 17 = 70.11 hp.....there's the problem.....:lolhit:.....whats the drive gear ratio ?

I'm not an expert but after I got mine off the dyno, I went to put them in gear at the ramp and they kept dying. I looked at the plugs and they were WHITE. obviously too lean at idle. I adjusted the idle screws at all 4 corners and that instantly cured it.

thanks for replies

Im guessing you're not in the States ??

1,200 rpm @ idle is pretty high......I think at a true 2000hp with a 1.5 gear and around a 30p prop you should be touching 80

I would guess way higher than that. Tiger with 6's and 1000's will be in the high 90's if not touching 100 propped right.

You cannot upload pics unless your willing to pay for a membership. You can link to pics by using a 3rd party site

yeah that's right in Australia the boat came from Canada across from Detroit from Tres. what gave it away :)

links don't work until 10 posts aparently.

yeah I would have thought 90 would be a closer figure.
thanks for info on idle.

can I ask what size fuel tanks a 99 topgun would have.

it drank over 200 gallons when it was filled but we have no idea what was in it previously as gauges and sender's might need replacing. that 70mph was done on full tanks with 3 passengers. it's has full cabin and we running 98ron gas.

the tanks should be marked, there is an access lid in the bilge on the step, 100-120 not sure....theres deff something wrong 6k @70 mph is soft.....what trans are in it

You adjust the carbs not switch props lol. 1200 is too high idle I think you need someone who knows how to tune carbs. Needs to be closer to 1000rpm neutral and 600-700 in gear.

Lower the idle and add fuel , if they are 4 corner idle adjustment start at 1 1/2 turns out
If really 1000hp and 70mph something is wrong .way wrong.

I'm assuming you're the Candyman? 😁

The mechanic played with the carbies for ages he said its really odd as the carbies where tuned fine and timings are also good but both engines where performing exactly the same Mechanic is an old school offshore race mechanic and still head mechanic in a offshore team, so pretty confident he knew what he was doing. We had limited time to get it sorted so yes prop change was quickest way to get us thru the through our event. Will revisit the carbies now we have time though, thanks for info.

Also I just checked the gps and it was set to knots not mph.. Stupid me... so we running at 80mph. Sounds better but will try to squeeze some more out of it. Thanks for the replies its appreciated.

That sounds more like it, good luck

Don't hold back, 70 knots is 84 mph. (Every mph counts) :)

RR

Congrats, Nice boat and power!!

I had also seen the video of the boat being wrapped, how well will the vinyl hold up on the bottom of the hull? I wrapped my previous boat and had some issues with the vinyl peeling around the corners at the transom, just curious how wrapping the bottom would hold up.

Something is deff wrong, i could run that boat up to 94mph everyday on 93 octane gas, What did you set the timing at? I was able to reach 97 mph the odd time in the right conditions. Those Trans have maybe 10 hours on them,1200 rpm is too high at an idle and you will eventually hurt the trans if shifting at that speed. Stalling was an issue at times when shifting with those engines, bumping the throttles during shifting helps. The engines are 589ci intercooled that Frank Mccomas from Scorpion Racing built which made over 1000hp on the dyno, not sure why you have to "trim them up to get it going"? tuck the drives in all the way and lower the tabs and give er it will get on plane no problem.....your most efficient speeds will be with the drives and tabs set on those little silver marks i put on the indicators. I could cruise at 70+mph around 4500 rpm.

Use the Flo Scans on the dash on the port side above the map holder. The boat holds 220 gallons, fill it up to full and reset the gauges using the little white switches underneath them. This will count how many gallons have been burnt. just have to subtract what was burnt compared to how much you put in.

If you REALLY want to get her moving i have Everything needed to convert it to a #5 boat on boxes, it will run right around 100mph but is a bit harder to get on plane...

I was wondering if that was your old boat..

Yeah, something's not right, or at least not setup ideal. Everything Big Farmer said jives with my setup too. I have to bump the throttles a little and need some carb adjustment for idle, just a reality with 18" dia props and carbed big blowers. Mine idle right around 1K, and in gear at about 700RPM, takes some getting used to docking and you WILL stall the boat out, especially when not warmed up or if they are loaded up from coming off plane after running/cruising. More seat time / carb adjustment and you should be just fine, and running 90+mph like BF said.

Like he said, put the 5s and boxes on, better yet 6s or Arnesons....

Hey Big Farmer, thanks for chiming in, we love the boat. Yeah mechanic thought it was odd. Didn't change the timing they said it was fine. I would have guessed they bumped the idle to get us thru the event. The only thing i can think of is the difference between fresh and salt water on the stalling issue. Once in gear its no problem just a little hesitant to bump the throttles whilst shifting. So solution was trim right up to take load of props to get into gear. Like others have said might just need more seat time.

You did where did you see that?

It was only really temporary for the event we had. The hull is starting to peel right at the front now.

agreed 100%
EDIT: 2 minute rule... I should have read more..

BTW Crowfoot, boat looked amazing black!

I had seen it on Facebook, Gold Coast Wraps posted it!

Facebook Link ^^ for some reason it wont show up unless I quote my post!

Careful trimming the drive up that high, you are putting a lot of stress on the gimbals. If you get a chance ask your mechanic what the timing was set at.

WOW! Thanks for the link. That thing came out beautiful with that wrap on. Those guys nailed it.

Crowfoot, your boss is an interesting guy!
Don't derail the topic, click below and keep it off this thread.
Candy Shop Mansion

RR

LMFAO....Holy crap....Ummmmm, ok then.

Got used to bumping the throttles to get it into gear at drives fully in. She topped out at 85.2mph at 5200 with the 31pitch 16s on an offshore rum today. wow very impressed on the handling of this hull. Will put the 33 four bladers back on and give it go.

Hey Bigfarmer. noticing we losing some steering fluid. Cant see any high pressure leaks anywhere, little bit of fluid in the bilge. Any ideas?

Speed and RPM sounds about right, slip higher than mine, Farmer - could this pull to 5600 - 5800 RPMs ever? Asking for my own benefit.

For example, I can get about 90mph @ 5200 RPM, BUT, I'm also running 18" dia prop where you are running 16". I would think you could get those RPMs touching the limiters with that smaller diameter prop?....

If trimmed properly ? and you cant pull the 31's past 5200, I think you'd loose rpm's putting the 33's on..........maybe a labbed 30 could get you to 5400. IDK, BF should know for sure.

We also had 8 people in the boat ( Mostly small girls :) ) with about half a tank of gas. 100gallons ish.

Pictures required if your gonna brag about it......:drink:

pics and video coming :)

33`s will lose a bunch of RPM and load the motors , it will become a turd sandwich. 29`s is what you need .

Anyone know the maximum people allowed on board a TG 38? Or where I would find this info?

Thanks all

My understanding is this only applies to boats with OB. Inboards and I/O's can stack like cord wood (must be facing it picturesque direction :D )