Yam 200 HPDI lost top 1k revs

Andy · 24 August 2007, 19:07

Today we lost the top 1k revs on our Yam 200 HPDI. The boat will managed 40mph ... but usually hits 50ish.

Tomorrow I will check the plugs and coils. Any other ideas before I throw it at a service engineer?

Thanks

codprawn · 24 August 2007, 19:40

I assume you have checked the prop and the drive leg?

Did it happen suddenly? Could be stale/dodgy petrol if the boat has stood a while.

Could also be the throttle cable has slipped.

DGR · 24 August 2007, 21:16

Has it been left afloat for a while for the lurgs to grow on it? Don't underestimate their ability to hold you back...

Roy Smith · 24 August 2007, 21:16

Checked the prop bush for slip ?

codprawn · 24 August 2007, 21:33

Quote:

Originally Posted by DGR

Has it been left afloat for a while for the lurgs to grow on it? Don't underestimate their ability to hold you back...

VERY VERY true!!!

prop slip would surely INCREASE the revs???

Andy · 24 August 2007, 22:40

It's used regularly.
No marine growth.
Last week it was fine. Today its lost 1k revs.
The throttle is fully open in the engine, when the helm is fully pushed, no slippage.
Petrol is good, swapped to an external source to check.
Prop looks ok. Not sure if its slipping.
Engine sounds like its missing a cylinder, hence my checks tomorrow.

Any other ideas please shout ... I will check for them all again tomorrow, dont want to miss the P1 boats in Sunday, got to get it fixed!

Thanks for you suggestions

Tony Hill · 25 August 2007, 08:33

Run the engine to warm, stop and take out plugs, look to see if any water on plugs - particularly bottom/lower ones. If water then its a new cylinderhead gasket. Better still test the pressure in the cylinder using a gauge. We have run HPDI's and have replaced cylinderhead gaskets on 4 or 5 of them at around 1200 to 1500 hours

Tony

Andy · 25 August 2007, 09:38

We seem to have no spark on one cylinder. The plug and coil are fine, i swapped them out with no change. Does anyone know if this engine would not use this cylinder at idle ... maybe its not meant to be hot at these revs?
If there is no spark and its not the plug or coil, what could it be?

Tony we are on about 400hrs ... and I cant see signs of water.

I guess its in to the service centre on Monday, and we will not be going out to watch the P1 Boats tomorrow .... shame! Its the best boating weekend of the year, the solent looks amazing this morning!

eupa · 25 August 2007, 11:49

There is a recall on this engine - to change the oil pumps. This for models prior to Oct. 2006. See my posts on this. -assuming your engine is a
a 2t V6 HPDI?. This should be under warranty.

sincerely

Jonathan

jwalker · 25 August 2007, 12:18

Quote:

Originally Posted by Andy

...If there is no spark and its not the plug or coil, what could it be?

This might help....or not.

Ignition system.

So, trigger coil faulty > trigger to CDI wiring faulty > fault in CDI > CDI to ignition coil wiring faulty.

The Garfish · 25 August 2007, 12:37

noe compreshun

Quote:

Originally Posted by Andy

our Yam 200 HPDI.

hdpi?

itts nott a kwestiun ov iff, jus a kwestiun ov wen

gaRf

blufin · 25 August 2007, 13:12

the 200 hpdi idles on 4cyl's in neutral and 6 when in gear (emissions).

jwalker · 25 August 2007, 18:08

It looks as though you need to put it into gear and try again Andy.

Tony Hill · 25 August 2007, 20:32

Also experienced similar problem as
The coil requires a permanent live feed - . Corroison in the live feeding the coil - picked up another permanent live and the engine returned to normal. Corrosion/abrasion of the main harness is a problem with HPDI

May be worth a quick shot to get you going - best of luck

Tony

Andy · 30 October 2007, 14:44

An Update on my loss of the top 1k revs issue.

The engineer has checked it with the laptop (twice) and all looks fine.
He has checked the spark strength - ok
Checked compression - ok
Fuel pressure at pump - ok

Yam are saying look at the injectors - micro filters nd so the engineer will now strip down the fuel side etc ....

This is becoming a pain the boat has been off the water for ages!

Tim M · 30 October 2007, 19:23

Andy
Saw you down at the Camber this morning with the cover off so assumed something was still up. Weird as I'm having a similar problem at the moment. I think I've managed (touch wood) to fix the problem - crap blocking the fuel supply.

Andy · 30 October 2007, 19:55

Yes that was us .. laptop plugged into the bugger!!! Someone tell me why boat engines seem to take voodu to fix!!

I thought it was you but only noticed as you left the camber.

Does anyone know a very good Yam mechanic in/near portsmouth .....

blufin · 30 October 2007, 20:23

inside the vapour seperator there is a pickup gauze for hi press pump that might be worth checking
gerry

landlord · 31 October 2007, 22:57

When did you last change all fuel filters.

Have had similar problems in the past, lack of power and unable to get max revs. Didn't believe it was filters until I changed them - was amazed at the difference !

9D280 · 01 November 2007, 13:42

Do you get "proper" WOT action for a bit then it drops 1k after X secconds / minutes use? If it's going into a "limp home" mode, it could be any one of your sensors are going in the huff or loosing contact. My only reservation about that thought is that if this is the case, I would have thought a far more spectacular drop in revs would be seen..... Unless Yam have been especially clever with their emmissions protection?

Probably worth checking every 'leccy connector under the lid - unplugging & replugging is usually enough to scrape off any cr@p on the contacts. Then reassemble with your favourite water dispersing fluid!

Most ECU faults (in cars anyway) will self clear if the problem isn't detected continuously / regularly, otherwise engine warning lights would become disco lights on the dash! Mind you, if you were out with the laptop plugged in, any fault code I would have thought would be flagged up even momentarily.

It's moments like this that old two- strokes have a certain appeal!