Merc 470 3.7 Warm Start Troubles

[zlman1970]

Re: Merc 470 3.7 Warm Start Troubles

I bought this stuff from O'reilly yesterday.

http://www.oreillyauto.com/site/c/d...p?ck=Search_heat+tape_-1_-1&keyword=heat+tape

It specifically mentions fuel lines. Too bad it is only sold in 15 foot rolls -- $18 for way more than I will use. It will be well worth it if it works. I will take some pics of the install and let you know how it works.

Any thoughts on how many layers I should use?

One wrap did it for me.

 

[Old Yeller Boater]

Re: Merc 470 3.7 Warm Start Troubles

I bought this stuff from O'reilly yesterday.

http://www.oreillyauto.com/site/c/d...p?ck=Search_heat+tape_-1_-1&keyword=heat+tape

It specifically mentions fuel lines. Too bad it is only sold in 15 foot rolls -- $18 for way more than I will use. It will be well worth it if it works. I will take some pics of the install and let you know how it works.

Any thoughts on how many layers I should use?

That's the same type of stuff I was thinking of and used on my camper. The adhesion was very good. I was thinking of overlaying the wraps half way which would in effect end up with two layers at any given point.

if you wanna send the excess to me, I can use more on my camper! ;-D

 

[SDSeville]

Re: Merc 470 3.7 Warm Start Troubles

That's the same type of stuff I was thinking of and used on my camper. The adhesion was very good. I was thinking of overlaying the wraps half way which would in effect end up with two layers at any given point.

if you wanna send the excess to me, I can use more on my camper! ;-D

If it works, I will gladly send you enough for your fuel line. No use in spending $18 for 2 to 3 ft of the stuff. PM me if I post positive results on Monday.

 

[Old Yeller Boater]

Re: Merc 470 3.7 Warm Start Troubles

If it works, I will gladly send you enough for your fuel line. No use in spending $18 for 2 to 3 ft of the stuff. PM me if I post positive results on Monday.

thanks, but just giving you a hard time. I can spring for the 18 bucks. heck, that's pennies in boating dollars. I wonder if there's a conversion chart. lol

 

[SDSeville]

Re: Merc 470 3.7 Warm Start Troubles

thanks, but just giving you a hard time. I can spring for the 18 bucks. heck, that's pennies in boating dollars. I wonder if there's a conversion chart. lol

Luckily it was car dollars at an auto parts store. West Marine would probably have charged $80 for the same thing.

I was at the marina the other day and the guy in front of me asks why his part was so darn expensive. The clerk told him that boating is expensive and to think of it as "marine dollars". He paid cash and asked if he could have his change in "marine dollars". It didn't work both ways...

It seemed funny in person...really


...and really, it would only cost me 50 cents in postage to send enough tape for the fuel line fix. Why should we all have 12 extra feet sitting in our garage for eternity. That $18 could be better spent on beer.

 

[Old Yeller Boater]

Re: Merc 470 3.7 Warm Start Troubles

how about if I paypal you some money to ship what you don't use? Like I said above, I can use it on my camper water lines. It's on a semi-permanent lot at the lake. Great for weekends! No sense it just collecting dust for you unless you have some idea for use.

I just hope it works for us!

By the way...did you see my other thread about my timing adjustments? It seems to have done wonders for my cold starts. I put in a new starter and battery. my timing was crap. adjusted it to 4* BTDC and it starts like a champ now. Just need to lake test it and then hopefully we can cure the warm start sluggishness.

Not going to make the lake this weekend though. gotta go to the beach for a wedding. ugh!

 

[SDSeville]

Re: Merc 470 3.7 Warm Start Troubles

That is cool having a camper on the lake.

I will have my fingers crossed this weekend. It would be nice to stop when a skier or tuber crashes, then just turn the key and start right up again without a complicated routine. What a concept.

I did see the other thread. Nice fix. I replaced the starter and batteries too. I now have 2 batteries with a Perko switch. I added a 2nd battery because I am always afraid the crazy warm starts might drain one. Luckily (knock on wood) my timing seems OK -- cold starts are easy.

 

[Old Yeller Boater]

Re: Merc 470 3.7 Warm Start Troubles

I'll check in on Monday to see how the results went. I'll have my fingers crossed!

here ya go...check this....

http://forums.iboats.com/showthread.php?t=572203&p=3929109#post3929109

 

[SDSeville]

Re: Merc 470 3.7 Warm Start Troubles

I put the tape on the entire portion of the fuel line between the carb and the fuel pump. I used about 3.5 feet. I put an extra vertical strip where the line is only about 1/4" away from the intake manifold.

 

[SDSeville]

Re: Merc 470 3.7 Warm Start Troubles

Ok....just got home.....and......the verdict is..........well, no magic fix. The boat did start significantly better today, but it was not any one fix. I made 3 changes for today that made the boat warm start pretty easy almost every time. 1) 2 batteries with Perko switch (started on "all"); 2) wrapped fuel line; and 3) did as Terry suggested -- started with 1/3 throttle and back off as it catches. With all 3, starting was pretty darn good. I wouldn't say great, but much better than any time in the past. I tried each one on its own and I didn't notice much of a difference, but all 3 together worked great.

Thanks for the help everyone!

 

[Old Yeller Boater]

Re: Merc 470 3.7 Warm Start Troubles

Thanks for the update. My cold starts are working great now. This weekend I'll definitely have the boat in the water to test the warm starts.

 

[Old Yeller Boater]

Re: Merc 470 3.7 Warm Start Troubles

Got a chance to test the boat out on the lake this weekend. My results with warm starts were pretty similar to yours. There was one time that it sat for about 20 minutes and took more throttle to get it to catch. another time it sat for only about 3 minutes and it caught right away. I guess with warm starts, it's a matter of getting used to it. My cold starts worked great though.

 

[SDSeville]

Re: Merc 470 3.7 Warm Start Troubles

Glad the cold start issues are gone. You are right with the warm starts -- you just have to find the best way and get used to it.

 

[SDSeville]

Re: Merc 470 3.7 Warm Start Troubles

Hi Everyone. I have gotten much better at the warm starts, thanks to the advice I was given on this thread. The heat tape and starting procedure really helped. 1/3 throttle until it catches and then back off seems to be the best trick. It is real hard to do because for some reason I always seem to want to give it more throttle as it catches, but it works much better to back off a little.

However, heat in that doghouse is still an issue. Last night, I tried opening the padded lid over the top of the transom compartment a few inches while we where fishing and it seemed to help cool things down a bit. But after a few hours, I can almost hear the fuel boiling in the carb (and I can surely smell it) after I shut her down.

Do any of you have suggestions on helping to cool the engine compartment when the motor is not running? Maybe more venting around the doghouse?

Also, I read in another thread that putting a spacer between the carb and the intake manifold can help keep the fuel in the carb a little cooler? Any thoughts on this? Where would I get one of these spacers?

Thanks for the help

 

[SDSeville]

Re: Merc 470 3.7 Warm Start Troubles

Somehow, I missed Ron's post from this morning -- http://forums.iboats.com/mercruiser-i-o-inboard-engines-outdrives/vapor-lock-not-612892.html

Eerily similar...

 

[SDSeville]

Re: Merc 470 3.7 Warm Start Troubles

I think I will try both ideas from Ron's post -

1. I already know it starts better if the engine is exposed while it is not running, so I do have a ventilation issue. Where and how do you add venting to your traditional doghouse that has a seat on each side?

2. Add a spacer between the manifold and the carburetor. Where can I find one for a Mercarb 2 barrel? Does iboats sell them (couldn't find it on the web site, but I might not be using the correct name)?

 

[natemoore]

Re: Merc 470 3.7 Warm Start Troubles

I put the tape on the entire portion of the fuel line between the carb and the fuel pump. I used about 3.5 feet. I put an extra vertical strip where the line is only about 1/4" away from the intake manifold.

View attachment 163469View attachment 163470View attachment 163471

Unless that tape has some foam insulation, I don't see how it would do any good. Just imagine trying to use a couple layers of aluminum foil as a pot holder and pick up a hot skillet.

 

[SDSeville]

Re: Merc 470 3.7 Warm Start Troubles

Unless that tape has some foam insulation, I don't see how it would do any good. Just imagine trying to use a couple layers of aluminum foil as a pot holder and pick up a hot skillet.

That makes sense Nate, but that is what they sold me at the autoparts (I know, I know...) store. It even says it is for fuel lines. I am definitely willing to try something else. What did you have in mind?

 

[SDSeville]

Re: Merc 470 3.7 Warm Start Troubles

Thanks to many suggestions on this and other threads. Today I wrapped the fuel line in 2 layers of 1/2" fiberglass pipe insulation (temp rating up to 300 F) and then wrapped it with a couple layers of the reflective heat tape I used last time. I am going back out tomorrow so I will let you know if it works.

 

[SDSeville]

Re: Merc 470 3.7 Warm Start Troubles

Well, just got home tubing and boarding all day and the insulation did make a noticeable difference. It still doesn't crank right up the second you turn the key, like my 3.0 used to. However, the gas smell was much less and I never got the feeling it wouldn't start. My old routine (1/3 throttle till it catches, then back off) no longer worked. I started at 1/3 and went to just about full throttle and it fired up within a few seconds every time -- even when run hard and let sit for 10 to 15 minutes.

I might consider the spacer down the road, but I am pretty happy right now.