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Surfer
08-22-2005, 05:22 AM
Hi,

just noticed last week my MC Pro Star 190 (, 1995, 1940 hours) top speed is 6 MPH less than it is used to be. Earlier 42 MPH, now 36 MPH.

The boat was about two weeks not used in the harbour. Engine works just like normal otherwise.
Normal spring maintenance was done in May.
I wonder if it could be flame arrestor being not so clean, something with transmission, ie. the prop axle joint tightness, antifriction bearing (of which two I do not know much about), or something else.
Anyway I am going to check and clean the flame arrestor.
Also if the green stuff on the hull, can it cause that much?
I am not sure if the speedo show's correct?
They were calibrated with gps just a month or so, ago.

I can verify this speed by barefooting: long line one foot almost impossible.

Other question: the manual tells to change oil every 50 hrs, which is close now, but the oil is still very clean, so any point? Except, it could be good to clean the hull at the same point.

Thank you for any answers!

jimmer2880
08-22-2005, 06:53 AM
I bet it's the fuel pump. Actually, it may only be dirt in the fuel pump. In 95, fuel went from the tank into the pump (located on the lower passenger's side rear of the engine compartment), then into a fuel filter (hard metal), then into the throttlebody.

step:

1) shut off fuel at the tank (pull the rear access panel & rotate shut-off valve
2) Pull the pump out (need to be a midget contorsionist standing on your head)
3) remove the adapter fitting on the pump where the fuel-line entered the pump.
4) check the screen on the pump for debris.
5) clean pump, re-install
6) install cheap-o fuel filter in the soft rubber line before the pump.

If there isn't any debri in the pump, a new pump is $270.00 from www.skidim.com (http://www.skidim.com). I will sell you a used one for $100.00 + shipping that I guarantee will work.

hope that helps....

MarkP
08-22-2005, 07:35 AM
I would start by cleaning the hull. You will pick up speed.

I’m going to guess you should change the oil (before) it is dirty..

G-man
08-22-2005, 09:44 AM
I would clean the bottom, with our temps here water in the high 80's you ger the start of growth in 24hrs.

Leroy
08-22-2005, 10:18 AM
Guy told me Sat he loses 10 MPH topend due to the build up on his hull.

east tx skier
08-22-2005, 10:20 AM
Welcome, Surfer. I'd also suggest that, if possible, after you clean the hull, put a coat of wax on there, too.

Surfer
08-23-2005, 04:50 AM
Hi!

Thanks for the reply all.
1. Hull cleaning.
2. I will check check the pump.

I did change this spring the filter before the pump (the one with nuts, and on a metal fuel line). I did not get the filter (the one on top of fuel tank on rubber lines) from the MC dealer (MC UK).
Anyway this filter, I did change, stops smaller particles.

As far as I know there are two filters before the pump, referring to a earlier discussion in this site: http://www.tmcowners.com/teamtalk/showthread.php?t=1089&highlight=fuel+filter

Thanks.

jimmer2880
08-23-2005, 06:46 AM
Hi!

Thanks for the reply all.
1. Hull cleaning.
2. I will check check the pump.

I did change this spring the filter before the pump (the one with nuts, and on a metal fuel line). I did not get the filter (the one on top of fuel tank on rubber lines) from the MC dealer (MC UK).
Anyway this filter, I did change, stops smaller particles.

As far as I know there are two filters before the pump, referring to a earlier discussion in this site: http://www.tmcowners.com/teamtalk/showthread.php?t=1089&highlight=fuel+filter

Thanks.

on my '95 - there were none before the pump & 1 after. Now, I put one before & removed the one after. Perhaps someone before you already had the pump problem & had the one before the pump installed?

Surfer
08-23-2005, 06:57 AM
Hi,

I am not totally sure if the filter I did change is before the pump.
Anyway I am going to check this issue today.
No pressurization needed? Or new seals?

Cheers.

André
08-23-2005, 07:02 AM
Is the engine running fine at 3600 rpm ?
If it's a fuel issue,the engine should bog when at full throttle...There's also a screen at the inlet of the pump...http://www.tmcowners.com/teamtalk/showthread.php?t=3977&page=2&highlight=Noisy+fuel+pump

Surfer
08-23-2005, 07:18 AM
Actually, earlier with 42 mph, the engine revs much less than the WOT value, if I remember correctly. According to the manual it should be 4000 or more?
The prop is 4-blade 13x13, so not the original one.
I will check the revs today as well.
But what could be the reason?
The engine does not bog, if that means slowing down or "misbehaving".

BriEOD
08-23-2005, 07:31 AM
Wow you're in Finland? How is the water temperature? Are you skiing in fresh or salt water?

Surfer
08-23-2005, 07:55 AM
Heh, yes, I am living in Finland!

Outside now it is over 20 Celcius, 68 Fahrenheit.
Water would be I guess less than 20 Celcius, ie. less than 68 Fahrenheit now. In July the water was around 77 Fahrenheit.

I do ski on a lake. Occasionally on sea, which I do not prefer for waterskiing.

Max. I have been skiing 6 months in a year in here.

sizzler
08-23-2005, 08:10 AM
welcome surfer.....where abouts in finland????helsinki???....

boys they have 190,000 lakes in that country..... :woohoo: with 5 million people.......thats gotta be some empty lakes :headbang:

Surfer
08-23-2005, 08:30 AM
Sizzler: 15 km from Helsinki, Espoo is the city called.
You've been skiing with the gb barefoot guys? http://www.gbbarefoot.com/

Anyway any suggestion to my WOT issue earlier?
I am soon going to check the previously mentioned issues.

T Scott
08-23-2005, 08:33 AM
Have both your rpm's and top speed dropped together? If you are still getting close to the same rpm reading at WOT, I would guess your speedometer has gotten out of adjustment. If you are turning the same rpm's as before and still experience a decrease in speed than I'd guess it is your bottom growth. Good luck!

sizzler
08-23-2005, 08:40 AM
on barefoot central..Pasi Siiskonen is that you then????

MarkP
08-23-2005, 08:51 AM
Hey surfer,

Hopefully you will clean that bottom and the WOT speed will be back to the way it was.

Now, I am going to have to ask to see some photographs of that craft of yours and possibly some shots of those lakes as well:headbang:

Surfer
08-24-2005, 05:06 AM
Hi!

I did clean the hull, the boat was on water, heh.
A long rod car/boat brush.
And got almost 6 MPH of the speed back!
Amazing that the dirt affects that much!
A good cleaning plus wax maybe gets the speed back to 42 MPH.
By the way isn't that close to the max with my boat, 275 hp?

Also, I noticed some bogging (correct word?), at full throttle.
Ok, I tried it end of skiing, and the gas tank might have been pretty empty (end of gas, though feels different).
Today or tomorrow I am going to check the gas pump.

Would you have part code for the fuel filter just after the tank (the one on rubber lines)?

Weird that same year same boats come with different construction, some have 0 filter, some 2.

Yesterday 40,5 MPH was just a bit over 4000 rmps.

Images, yes I will attach those to my profile soon.

jimmer2880
08-24-2005, 06:20 AM
For the filter after the tank, just go to an automotive store & get a (to me, it's 3/8" diameter fuel line) in-line filter for a v-8.

www.skidim.com (http://www.skidim.com) is down right now, otherwise I'd post a link to the exact one I have on my '95.

Surfer
08-26-2005, 04:59 AM
Hi,

I did change the 1st fuel filter.
Did not open the gas pump, as it is totally in a bad place.
Also as with full revs the boat works ok now,
40,5 MPH with 4100 revs. I did add gas, heh heh!

Fuel system works ok. Interesting would be to know how it works. :banana:

There comes two lines from two different spots on top of the tank, the other with the 1st filter in the line. One line goes "through the pump", the other line goes straight to the carburator injection head?, though a T-connection to the gas pump.
Totally weird consctruction? Any clarification?

Indmar manual tells something.
Which document could tell more?

herevard
08-27-2005, 05:57 AM
Hi neighbour,

I'm from Lithuania. I have 1990 ProStar, 240 hp. Top speed is about 41-42 mph. Did you check your secondary opens? Secondary gives about 6-8 mph.