Honda 40 won't throttle up until warm/hot

[Chuck.H]

Hi - <br /><br />I have a 1998 honda 40 that won't run well until it has run for about 20-30 minutes - after that it will run fantastic for the rest of the day. It seems something temperature related is not working until it gets warm or hot. For the first 30 minutes or so, here are the symptoms:<br /><br />Starts and idles ok.<br />When giving gas, it does not increase in rpm's very much, and stumbles like it's not getting enough fuel or only running on 1 cylinder or has a very weak spark - if it had a distributor, I'd suspect moisture in the cap - it feels like that.<br /><br />Squeezing the bulb will not improve or even change the condition. The bulb is firm.<br /><br />As it gets warm, it will sporatically run better, then worse, until at 30 minutes or so it goes away and will run great the rest of the day.<br /><br />The next day it will begin the cycle over again - it's very repeatable in that for the last 10 times I've had it out it's done this every time in the morning. Most days I've had it out the temperature has been in the 60 - 80 degree range.<br /><br />At first I suspected the carb's, (I've checked the vent hoses btw, they're clear) but since it's so repeatable I'm now suspecting some ignition component is not working correctly until warm. I did put a timing light pickup on all 3 cylinders and they're all firing.<br /><br />I took it to the dealer and they said it had dirty spark plugs, that's the problem - they also said it went away after cleaning the plugs but I think it just got warmed up, because it didn't go away.<br /><br />I guess I'll take it back to the dealer, but I was hoping someone had previous experience with the same problem...<br /><br />Sorry for the long post,<br />Chuck.H<br />chuck@lw.net<br />Gainesville Fl

 

[ehenry]

Re: Honda 40 won't throttle up until warm/hot

Just a guess....maybe a thermostat stuck open or something like that?

 

[Skinnywater]

Re: Honda 40 won't throttle up until warm/hot

Hello Chuck,<br />I'd like to assume the repair shop visually inspected choke operation, manifold tightness, fuel filter, wire connectors for corrosion, secondary ignition wires for corrosion and arcing, and the all to important valve adjustment.<br /><br />Have you yourself inspected any of the above items? <br />Did your problem happen all of the sudden or was it a gradual worsening problem?<br />Is your BF40 a remote or tiller type? <br />Approx. how many hours on your motor and has it had any valve adjustments?<br />Does the motor have a defined misfire or is it simply running roughly on all three?<br /> Please report back to us and let us know the ultimate cure?

 

[Chuck.H]

Re: Honda 40 won't throttle up until warm/hot

Hi Again - <br /><br />The BF40 is remote steering, and it's on an older 13' whaler - a great combination IMHO.<br /><br />I think there are about 140 hours on the motor, it has had regular servicing which I'll assume includes valve adjustments and fuel filters.<br /><br />When it's acting up, the symptom can best be described as *no power*. It doesn't run all that rough, but the boat will only accelerate to 15mph, where normal WOT is 40mph (I think my spedo is mph not knots). I'm pretty sure it's not the throttle linkage(!)<br /><br />When it stops acting up (after 30 minutes) it will run very close to perfect, BUT now that I think about it, while it's running perfect it will have an occasional hiccup, like one every 15 minutes or so - running along at part throttle and you'll hear/feel a VERY slight cough from the engine - just enought to make you look back and take notice. Mmmmmmaybe these two are related.<br /><br />But otherwise it runs so friggin smooth it's truely a work of art and draws attention for that and how quiet it is all the time.<br /><br />As for the choke, it works great and starts the engine in one second when cold, and smoothes it right out when released.<br /><br />At this point I'm suspecting ignition problems - I can't believe crap in one or more carbs would come and go so regularly...<br /><br />Chuck.H

 

[Skinnywater]

Re: Honda 40 won't throttle up until warm/hot

Hello Chuck,<br />It's very possible your hunch is correct. <br />If you were so inclined to remove the plastic cover on the electronics maybe you'd find a connection/corrosion problem on one of the primary or secondary ignition wires. However, a trip back to the dealer is called for anyway.<br /><br />Again, let us know what is ultimately found.<br />Good luck and tight lines on the Micanopy.

 

[PlanB]

Re: Honda 40 won't throttle up until warm/hot

You might check or change the thermostat. It is very easy to get to, similar to an automotive setup.

 

[John Hzzzzz]

Re: Honda 40 won't throttle up until warm/hot

Did you read my comments from your last post of 2 March regarding the thermostat. Your title was Honda 40 Gas in Oil.