AQ 151 WONT START WHILE ITS HOT

"Hello all, I am new to the wo

"Hello all, I am new to the world of Volvo Penta's. I have a AQ151 with a 290 outdrive. It runs and starts great. (WHILE ITS COLD) but if I go for a run and then shut it down. It wont start . I have to wait 15-20 min then she starts fine. This will also happen if I idle it for a while the go to put it in gear she will die and wont restart. Any suggestions Thanks TJ"

"When that happens again, and

"When that happens again, and with the engine in neutral, put the throttle lever between 3/4 and full throttle and crank the engine for 3-5 seconds; just be prepared to back the throttle lever quickly once the engine starts firing."

"El Pescador, Thanks for you r

"El Pescador, Thanks for you responce. I have done that,and all it will do is crank over, it wont fire. it has 1 year old points, condesor, cap. and plugs.It only has 10 hours since part were put in. It seems like it is Flooded. But also when it does start. It only starts as I let off cranking it. while i am cranking it it dont fire it only fires when i quit cranking.

thanks for your input

TJ"

"Thomas, I agree that it seems

"Thomas, I agree that it seems flooding. My old AQ140 gave me some challenges at the beginning, and the suggestion I made in my previous post always worked.

I don't know for how long you have owned your boat, or how aware you are of its history, or what maintenance you have done to it. A few things you may want to do include:

1) Get rid of points and condenser and install a Pertronix electronic ignition kit. You will be amazed to see how much easier your engine starts, even dusring cold and humid weather. Take the opportunity to inspect the springs and advance weights in the distributor.

2) Make sure the wiring from the ignition switch to the coil is in good condition. If questionable, replace it with marine tinned wire.

3) If you don't know the age of the distributor ignition wires, install a new set. Afterwards, adjust the ignition timing.

4) Get hold of a uni-syn carb synchronization tool and make sure both carbs are synchronized.

http://www.minimania.com/web/Item/UNI-SYN/AddedFrom/CatBrowse-%20TOOLS/InvDetail .cfm

Afterwards, adjust both carbs idle mixture and engine idle speed.

5) If the failure to start the engine is intermittent, consider the coil as being suspect. Luckily, coils are not expensive, just make sure the one you install has a primary resistance of just over 3 ohms.

6) If you haven't done so by now, take the time to do a compression test in your engine.

I am 100% convinced that your engine should give you many years of trouble-free service if properly tuned and maintained. However, I think it is important for you to know the condition of what you have now so that you can establish a maintenance baseline and you can trust your engine. In the end, it is usually cheaper (and less frustrating) to replace a few critical parts now and go to sea or to the lake with peace of mind rather than taking the family for what is supposed to be a day of fun and finding that your engine keeps letting you down for no apparent reason."

"This is a common trait on the

"This is a common trait on the older 130/170's. The more the rings wear out the harder it is to start when hot, could this be it? Check your compression cold and hot. Also when hot how much blowby is there from the crankcase vent?"

"Boat Doc, the engine that is

"Boat Doc, the engine that is giving Thomas trouble is an OHC AQ151. Nevertheless, some principles are common between OHV and OHC, and I know of no engine that likes low compression ."

"Sounds like a bad coil, conde

"Sounds like a bad coil, condenser or resistor. I say this because the spark appears to be weak and heat can cause intermittant problems with these items. The points and timing must be reset every 30-50 hours run time. If wear is evident replace all the usual suspects with new, especially the condenser."

"Just got back from a little i

"Just got back from a little investigation. I found when cranking over the engine or pumping the throttle, alot of fuel pumping out from around the bottom of the primary jet but not out of the jet (I think)on the rear carb. And the jet wiggled a lot where the front carb jet did not wiggle. So i took the top plate off and found a screw beside the jet was loose. I tightened and no more fuel pumping out around the jet. I will be going out today . HOPEFULLY all is ok now, thanks for all your help"

"Thank you. Sometimes, we don&

"Thank you. Sometimes, we don't hear back from folks regarding the outcome. Just to be clear, are you talking about a jet or the accellerator pump nozzle? The gizmo is held in place with two screws. However, none of the two fuel jets, the air/fuel bleed, nor the air jet are held with screws. Nevertheless, it sounds like a flooding problem so the guys who spoke to this were probably right."

Another thing I would check is

Another thing I would check is your ign switch. Only reason I say that is your comment about it catching when you let off the key. the "run" circuit might not be solid in the start position...

I understand he has a OHC. I w

I understand he has a OHC. I was just relating what CAN happen. I have a customer whose AQ140 got so bad one couldn't stand being in the boat with the blowby it had. He had removed the breather hose from the airbox and routed it into the engine bay randomly. Then routed it out though the side vent which was better. It finally would not start when hot and his cure for that was he never shut it off during the boating session. We finally repowered with a good used 151.

"Randy, right. Either he has a

"Randy, right. Either he has additional problems with that engine or the crossword puzzle has too many squares."

"I still have a similar proble

"I still have a similar problem. it (1986 AQ260B) Wont restart when hot, i get a clicking sound, then silence.
I tried again today, no clicking just silence, now it wont even start cold.
I have a new starter on the way, because I was sure it was a selenoid issue. any thoughts would be greatly appreciated."

"In my opinion, either the sta

"In my opinion, either the starting relay is acting-up, or there is not good ground between the engine block and the (-) of the battery."

"El Pescador, again thank you

"El Pescador, again thank you for your willingness to help. Is this part # 841177 that you are refering to? How is this different than part # 841178 40 amp fuse?"

"Hello all, I guess it was act

"Hello all, I guess it was actually it was the accelorator pump nozzel that I had to tighten down. I have been out the last two days started many times with not one problem. and it runs and idle's so much better. I am greatful for all you help. Great site you have here.

Thanks TJ"

"Joe, part 841177 is a relay m

"Joe, part 841177 is a relay meant to carry a higher electrical load than the ignition switch can handle, and part 841178 is a 40 amp reset breaker for wire thermal overload protection. They are as different as apples and oranges.

http://www.dougrussell.com/partscatalog/volvo_omc/index.cfm?fuseaction=comp&grou p=2237&GroupList=2218,2219,2220,2221,2222,2223,2231,2224,2225,2227,2226,2228,222 9,2230,2232,2233,2234,2235,2236,2237,2239,2240,2241,2242,2243,2244,2245,2246,224 7,2248,2249,2250,2251,2252,2253,2254,2255,2256,2257,2258,2259,2260,2261,2262,226 3,2264,2265,2266,2267,2268,2269"

"Sorry for the confusion on th

"Sorry for the confusion on the fuse.
I replaced the relay tonight, and checked the grounding, still nothing. the red button at the fuse (841178) is popped out, (simmilar to a GFI in your home), should I be able to push this back in to reset it? it wont seem to stay in, as if the fuse has tripped. I still have the new starter on the way, should be here in a couple of days. Could the ignition coil be the culprit?"

"Two things could be happening

"Two things could be happening here: either the breaker is not resetting because it is defective, or because there is a short somewhere after it. To find out whether the breaker is good or NG, just identify the two wires attached to it and measure the voltage between each of them and ground. If bot read 12V or more, the breaker is OK; but if only one measures 12V, then either it is defective and should be replaced or it is tripping because of a short (full ground)."