Testing this weekend

[Dienewk]

Re: Testing this weekend

beign that ngk really dominate over here now i had to order the Champions in but i got to sets to save the hassle next time

i will set and replace the plugs when they arrive run a new fuel tank and delivery line and then report back from there.

thansk for all the help so far guys

 

[Willyclay]

Re: Testing this weekend

I also called the mechanic that just rebuilt the carbs(he is local so no 4 hour trip there) and he is a little stumped as everthing balanced up fine and ran in the tank just great he is getting back to me.

They always run great in the tank! The real test is on the boat, in the water and underway so the motor has a load on it. Those conditions can only be duplicated in a tank if the proper test wheel/prop is used.

Any vented tank with an adapter for a single-line hose will work fine with your motor. It can be steel or plastic, OEM or aftermarket.

Where exactly is "over here", if I may ask?

 

[Dienewk]

Re: Testing this weekend

They always run great in the tank! The real test is on the boat, in the water and underway so the motor has a load on it. Those conditions can only be duplicated in a tank if the proper test wheel/prop is used.

Any vented tank with an adapter for a single-line hose will work fine with your motor. It can be steel or plastic, OEM or aftermarket.

Where exactly is "over here", if I may ask?

I am in Australia "mate" lol and these forums are one of the best all round i have ever used, the help supplied and the brains here are awesome.

 

[Willyclay]

Re: Testing this weekend

115 1973 - 1979 QL16V Surface Gap or QL77JC4 .030 should be mine surface or normal?

I haven't been called "mate" since working TDY with two Irishmen in Bermuda back in 1972.

Totally agree with you about how great this site is for recreational boaters. Wish it had been available back in 1974 when I got my first boat&motor that Dad did not purchase.

I had to search for a BRP sparkplug chart to verify the Champion numbers for your motor. Those are correct on a chart dated 2005. The 2007 & 2008 charts I found do not list that model motor for some reason. Maybe one of the forum experts would care to comment.

In response to your Q about which one to use, it's like anything else; some members like the surface gap version and some like the standard gap version. One powerful argument for using the surface gap plugs is the unknowns about this motor from previous owners. If one or more PO had the heads milled/trued, enough material may be removed for a standard gap plug to make contact with a piston which is obviously a very bad thing!

Proceed cautiously until you can determine exactly what your situation is with this motor. Some members say one version or the other runs better for them or does not foul as easily. You will just have to make that judgement for yourself once the performance issues get resolved. Good day!

 

[Dienewk]

Re: Testing this weekend

hey guys

a mate of mine has a spark tester so i have borrowed it from him (might as well test that as well) how far should the spark jump on one of these to be "healthy"?

Tim

 

[Willyclay]

Re: Testing this weekend

The gurus say a minimum of 3/8" and describe healthy ignition systems with a 7/16" bright, blue spark.

 

[Dienewk]

Re: Testing this weekend

i cant get the boat back on the water till after xmas so i have done a few things here.

I replaced the NGK plugs with the Champions, i then tested the spark

Plug lead 2 wont jump 7/16 but will do 3/8
Plug lead 4 will do both
Plug lead 1 both
Plug lead 3 both

when i wound the tester in to what the plugs are it was good healthy blue spark.

I got a new fuel tank with a breather screw in the cap, (the old OMC tank used to hiss every time i opened it with the pressure build up? didnt breath?)

Bought a new fuel line but have to re-route where it goes as the new one is 6ft 10" but the old one was 9ft 10". i couldnt find any 9ft hoses in the shop or online, but i suppose i can make my own if need be.
is 9 ft to long?

 

[Willyclay]

Re: Testing this weekend

Compression and ignition both checked out okay, so it looks like you still have insure good fuel supply and delivery. New hoses are a very good upgrade. I have seen guys put their tank in the bow and run the hoses all the way aft. Also, the new tank is great because that "old OMC" tank sounds highly suspect. Try it again in the water with the correct Champion plugs, new tank and hoses before you touch the carbs again. You might just get lucky and find it is working well. Good luck and Merry Christmas!

 

[jonesg]

Re: Testing this weekend

Is that the wrist pin covered in rust?
definate sign of water there.

 

[Dienewk]

Re: Testing this weekend

Is that the wrist pin covered in rust?
definate sign of water there.

nah its been sitting around in the weather hence the rust on that part

 

[Dienewk]

Re: Testing this weekend

got the chance to go camping with the family for the last few days so took the boat out for a run, with the new spark plugs and new tank and line


sad news is it still stalls a lot and is hard to start, when we first attempted to start it i flattened a battery and the smell of fuel was strong (i disconected fuel line and left it tilted over night) i tried again the next morning but fuel was again pising out, i took the cover of the front of carb and heaps of fuel present, i played around and got it to fire and run at high revs with the warm up bar.

We took it out for a run and as always at WOT and cruising it was awesome but as soon as we return to shore it stalls. i can restart using the warm up lever then i acclerate away only to have it stall so i let it drag for a while and hit it some times it take of other times it stall, the engine was a fair bit smokey and smelly(fuel)


i think i am destined to have a tought to drive boat lol.


my next step is to find "another" mechanic that can test the boat for me on the water rather than in the tank.

thanks for all the help


yours trully
buggerred boat.

 

[ezeke]

Re: Testing this weekend

Two things stand out:

first, the fuel leakage is probably from a malfunctioning float valve which is sticking open. Be sure that the float is parallel to the carburetor body with the carburetor held upside down;

secondly, it is extremely important that the warm-up lever is raised all of the way for a cold start because that advances the timing and increases the fuel flow a bit.

Starting these engines cold always requires full, absolutely 100% closed choke plates which can only be verified by observing the actual plates while cranking. And, the engine must be turning at 300 RPM which requires a fully charged powerful battery.

There are no midrange orifices or jets in your carburetors so it is very important that the idle jets are clear and that the four tiny capillaries opening into the bottom of the throats of the carburetors are clear.

 

[Dienewk]

Re: Testing this weekend

thanks ezeke
i think that is why it flooded so bad at start up, cause it was stuck open.



i spoke with another mechanic today and he said the top 2 relief ports maybe under water at start up this can cause them to stall and be a dog until the boat manages to get up out of the water, if this was the case then that would suck as this would mean the boat is useless at all take offs? and only good when theses ports are out of the water.

 

[Willyclay]

Re: Testing this weekend

this would mean the boat is useless at all take offs? and only good when theses ports are out of the water.

Any chance you can do an in-the-water test with some passengers/ballast safely forward to bring the two motor relief ports out of the water for startup and initial forward movement to see if this new mechanic has it correctly diagnosed? It will not alter the facts of a 300lbs.+ outboard motor hanging on the stern of a 14.5ft boat but it might solve the performance issues. As far as a fix to the boat's bad at-rest attitude, some forum members have installed "flotation pods" on their boats. You might try a search for those keys words and I'll try to dig up some old threads for you. Just throwing out a possible solution for an inherent problem.

EDIT: Here's a link to the flotation pod thread. Take a look at the homebuilt boat link also.

http://forums.iboats.com/showthread.php?t=347941

 

[Dienewk]

Re: Testing this weekend

thanks willyclay.

i tested what this mechanic has said and he may really be onto somethign here.

i backed the boat into the nearest water suply and got the exhaust ports as low as i could and created as much turbulance near them as i could and sure enough it stalled out but if ilet it run a bit further out of the water it wouldnt miss a beat.

i have some adjustment holes to make the engine higher is there consequences of moving the motor up higher on the Transom??

sick of me yet?

 

[Willyclay]

Re: Testing this weekend

Great, some positive news about your newest mechanic. The results of your uncovered exhaust relief testing is consistent with normal expectations based on the design of that motor. You did not mention the previous hard-starting issue. Just curious!

Yes, an adjustment of the motor heighth on the transom may be a corrective measure BUT other performance issues may be created such as prop ventilation, low cooling water pressure and underway handling problems. At this point, a picture or two of the stern view of the boat out of water would really help before recommending this next step. If you can stage the pictures with the motor trimmed down and the anti-ventilation plate as close to parallel with the bottom of the hull as possible, it will enable the forum members to make the best judgements. Payload/ballast adjustments such as placing batteries and fuel tanks forward can also help mitigate this problem.

Finally, no way am I "sick of you yet"! I appreciate your patience and understanding as I/we try to help you from the other side of the planet. There is a bit of envy however, because locally we have experienced a week of below freezing temperatures while you are trying to enjoy the boating season. Good day!

 

[Dienewk]

Re: Testing this weekend

There is a bit of envy however, because locally we have experienced a week of below freezing temperatures while you are trying to enjoy the boating season. Good day!

mate 44 degrees here yesterday or 111 on your scale, a bit warm

 

[Dienewk]

Re: Testing this weekend

guys just drew a rough (very rough) picture of a idea i have.

i was thinking if the relief ports are bobbing under the water can i add something to the relief ports to extend them.

my first thoughts where to use copper pipe bent up (to face the sky) and hence keeping the ports out of the water.

as i say this is only an idea and may cause far more propblems than fix them so i just wanted to put it out there to get ideas.

i am yet to change the position of the motor and cant get pictures of the boat in the water till the 23rd of this month when we go out next.

http://i461.photobucket.com/albums/qq332/dienewk/reliefports.jpg

 

[ezeke]

Re: Testing this weekend

That will not help, and may make the problem worse, because the exhaust housing fills with water to the point of the relief holes and will fill more with extensions, creating even greater back pressure.

 

[Dienewk]

Re: Testing this weekend

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