volvo 140A 4cyl not reaving up the rpm's

volvo motor was not reaving up

my volvo 140a i put in my 21 ft trophy is running crappy, when i put it in the boat it would only rev up 1/4 throttle then it would bogg down, it sounded like it wanted to run but would miss, it really did this in neutral the worst under load it didnt do it as bad, the spark plugs are burning black so that tells me they are not burning the fuel goin in , the compression is about 135psi on every cyl,i put new sparkplugs in it , and then i cleaned the 2 carbs and now it wont start at all ,there is no spark ,i think maybe it is the coil , i orderd new plug wires and a new coil it will be here on tuesday, how do i check my coil to see if it si it at all i am so close to having this boat goin its drivning me mad , although iam thankfull for it and didi all the work myself the sunner is slipping by and its not in the water were it belongs and cant afford a marine mechenice to look at it

 

my 21' bayliner trophy is just about all done, but i put the motor in and the engine wont turn up, it sound like it is missing it just has not power ,it wants ti go but just sputers it turns up about 1500- 2000rpm's i put new plugs and did a compresion test it was 130-135psi on every cyl. i cleaned the 2 carbs , they looked fine, i took them apart and clean them and blew them out with air, i then tryed to start the engine and now there is no spark once so ever so i orded a new coil and plug wires they will be here on tuesday, is there a way to test my coil and wires , i do have a amp meter , my boat is a great boat but it is no good to me sitting in my drivway , and cant afford a mechenice to look at it ,as i just replaced the transome and beds in it so any help would be greatly thankfull ,thanks guys

 

Take a plug and a HT wire, stick the wire in the coil's HT hole and have the plug make contact with the engine block. Remove the distributor cap and distributor arm, then turn the ignition key to the 1th position. With a screwdriver push the breaker points open without destroying them. There should be a small spark there and the plug should spark also.

If that works, the coil, resistor, breaker and capacitor are OK. The problem then is the distributor finger.
If nothing sparks, there is no power. That may be a burnt out resistor, bad contact or the safety switch.
If the contact breaker sparks, but the plug doesn't, suspects are the coil and the capacitor.
You can check the capacitor by unscrewing it's wire, apply 12V, wait a few seconds and then short it to ground. There must be a tiny spark both times.

 

your too kind

thanks alot, i really apeciate your advice and too take the time to write me back, i will try that out and hopfully it will work, would you have any idea what would make not turn up, thanks again,

 

Well, what i tend to do, to see if the coil is working, get a mate to hang onto one of the plug leads with a screw driver inserted, and why he/she is not watching, crank the motor over.

If they site there fat dumb and happy, the coil is not working, on the other hand, if the screw driver gets flung, and there is a mention about how they are going to kill me, the coil is working.

Hint: the distance of the screw driver from the motor is in direct proportion to the spark from the coil.

 

If its electonic igniton never never crank it with the plugs or HT leads disconncted .....that can bugger your electronic igniton ...to test coil measure primary and secondary resistance with and ohm meter 0.3-3 ohm on primary dependent on type ..primary 10 000 ish ohms ..put lead from coil centre to 6mm from block and crank ..if you get a 6 mm spark in air that part is ok

 

Just a warning, before you create an open spark near your block, fan the area to get rid of the fuel vapour. You don't want your newly restored boat turn to a pile of burnt rubble.

 

thanks alotdave , i put new wires ij it today and it run alot beter iam wondering if it is the coil the motor is reaving up in neutrul but in drive its not , only about 2000 rpm's i dont know what to do

 

still

i put a new resister and starter relay and condenser in it and new plug wires and set the timming with a timming light and its running away better ,the engine is turnning up ,but under load its not could it be the coil ? or the carbs ,there are 2 of them thanks alot
from kamloops canada, kevin

 

can you get a 6mm spark in air ? If no change the condenser and try again it wont run right if you dont have a spark that can jump the plug under cylinder pressures ...

 

confuesed iam so close

thanks , but i put a new condenser on it , anything else? iam goin to put a new coil tommorow, will that help do you think?

 

Since a few tune up parts made a dramatic difference, don't you think maybe doing a full tune up might be in order? It sounds like this boat hasn't received the love it needs to be reliable and you're suffering the results.

Get it tuned by someone familiar with these systems. While they're there, I'm sure they'll find the other problems you Volvo has, which sound minor, for what it's worth.

The other option is to continue the crap shoot of tossing parts at it, until you've accidentally hit the problem, which is a foolish and expensive way to diagnose you problems, not to mention isn't going to get things adjusted properly.

 

It's pretty difficult to follow this discussion across the several threads it's being pursued.

 

sorry,iam not much of a coputer guy atall, i''ll tell you whats goin on with the engine at this moment, it will reave up in nutural lots but when under load it only reaves up about 2000 rpm, (when iam cruising) maybe 9 knots, and it should get up and go way better then that , iam thinking weak coil? or maybe the prop is too big ,the motor is a older one about a 79 or older, and the boat is a 21ft bayliner trophy the pic'sare in my profile,the motor is a 140 volvo with dual carbs,i put new plugs and wires, new pionts, and had it timed also the motor sounds very nice, it just purr's, thanks alot for you help

 

good advice i will do that,it's just a guy gets so close to completion and i want to do it myself, but i'll have too now becouse every time i turn around iam dumping money into it and getting me nowere,thanks alot PAR,thats very wise of you,