Suzuki 70HP slow when cold

[jstachowiak]

The last couple times out my 2001 Evinrude 70HP 4 stroke with 92 hours runs a little rough at idle and bogs down at 2800 to 3000 RPM. After about 10 minutes of running, it runs great and runs great all day. Only acts up in first 10 minutes of running. <br /><br />I have an external aluminum tank, Sea Choice fuel filter separator, which has been changed.<br /><br />Fuel line and bulb are in great shape no leaks anywhere.

 

[clanton]

Re: Suzuki 70HP slow when cold

Have you ever drained the vapor seperator, change the primary fuel filter, adjusted the IAC valve, <br />check the valve adjustment, sparkplugs, hoses pinched with cowling ?

 

[jstachowiak]

Re: Suzuki 70HP slow when cold

I have not changed the motor fuel filter, will do that next. <br /><br />Where is vapor separator and IAC valve? or Should a Suzuki tech check this stuff?

 

[clanton]

Re: Suzuki 70HP slow when cold

The vapor seperator contains the fuel pump and regulator. Water will seperate from the fuel and settle to bottom of seperator, there is a drain screw to drain. Will have to check the manual for the IAC valve adjustment. Some models easy , just need a screw driver. When you change the fuel filter check for water, if water is in filter, water may be in the injector rail. The primary and secondary filters will pass water. If water found drain all fuel lines and rails. Water also kills the fuel pump and regulator. Low fuel pressure = poor idle.

 

[jstachowiak]

Re: Suzuki 70HP slow when cold

Suzuki dealer mechanic says any water problem will be constant and will not clear up once engine warms up. He suggested new plugs, which I bought and put in. Runs smooth on water hose in driveway, will try it out tomorrow and report results. Manual suggests new plugs at 100 hours, am at 97, so seems logical.

 

[jstachowiak]

Re: Suzuki 70HP slow when cold

Motor ran like it was new, today. So, spark plugs was the problem. $12 fix. Yipee.

 

[DaveG]

Re: Suzuki 70HP slow when cold

I have the same motor and same problem. Could you tell me what the spark plug gap is for the 70HP 4 stroke Suzuki?<br /><br />I can’t find the gap info on the motor or manual.<br /><br />Thanks<br />Dave Gulczinski

 

[Meggacatz]

Re: Suzuki 70HP slow when cold

The 98-02 Suzuki manual for the DF60 & DF70 sez' to use the NGK BPR6ES plugs with a gap of 0.7-0.8 mm or 0.028-0.031 inch.

 

[jstachowiak]

Re: Suzuki 70HP slow when cold

Gap question was a good one, since the manual does not say. <br /><br />So, I pulled all four plugs and checked gap on those and they were all the same as the ones I bought as they were. Plugs come with a cordboard sleeve to protect the gap end.

 

[DaveG]

Re: Suzuki 70HP slow when cold

FYI... I changed my plugs (total cost $7) and my problem also went away. I did finally find the plug gap information on a sticker close to the motor's transom bolts. <br /><br />Dave Gulczinski