Suzuki Primer Bulb

[Kiwi]

For some time now I have been having trouble with rough idle/slow-mid speed running. I have had the engine tuned at the local dealer but still the problem persists. I have noticed that the primer bulb 'never' gets hard when I prime the engine before cold starting. The engine does start easily, but idles rough and at 1200 - 1500 rpms is even worse. As you get beyond 2000rpm it runs fine with no problems at all. Would the primer bulb have any effect on these symptoms ?<br /><br />Thanks<br />Mike

 

[Ross J]

Re: Suzuki Primer Bulb

Hi Kiwi, The rough high idle 1200-1500 could be as simple as an incorrect spark plug gap. You don't say what the engine is. A plug gap set too small could give this problem and yet appear OK at the upper range. Check with your manual. Mine on an 85hp Johnson is 40 thou which seems big but they specify it and believe me it makes a difference.<br />The bulb not comming 'hard' could be a number of things to do with the valves at each end of the bulb. As long as there's no leaks - air getting in or fuel getting out - then this should not affect the running of the engine but would affect the start up procedure.<br />Hope this helps.<br />Ross

 

[DJ]

Re: Suzuki Primer Bulb

Agree with RossJ. If in doubt, the primer bulbs are cheap and does not have to be Suzuki.

 

[Kiwi]

Re: Suzuki Primer Bulb

Thanks for the replies. The engine is an 1989 Suzuki DT85. At the last service the dealer replaced the spark plugs, impeller and tuned it (apparently !) It does run slightly better than it used to but nothing like I think it should in that rpm range. I never thought to check the plug gap but will do so today. It appears to me to be some sort of fuel problem though. The only thing I haven't done is taken the carbs off and made sure everything is clean in there. I doubt that has been done since the engine was new. Not sure I feel confident enough to do that even though I have a workshop manual for this engine ! Assume all current carb settings would be lost during that operation ?<br /><br />Mike

 

[JB]

Re: Suzuki Primer Bulb

Ahoy, RossJ. Sometime in the late 80' OMC revised recommended gap on plugs. . . all models except those with surface gaps plugs.<br />They now specify .030.<br /><br />Red sky at night. . .<br />JB

 

[Pursuit2150]

Re: Suzuki Primer Bulb

I owned a Merc 90 hp. It would start fine run fine, until I punched it, then I had to tickle the throttle to keep it from a stall. Replaced the primer bulb, adjusted the carb linkage, and never had another problem. Give it a try, it may work. Another Problem I had was interference in the fuel lines. It might not hurt if you disconnect them & blow them out with air, mine had all kinds of junk in them.

 

[Kiwi]

Re: Suzuki Primer Bulb

Good idea - I'll try all suggestions and report back. Unfortunately its going to be about 10 days or so before I can get back to the lake. Thanks all.<br /><br />Mike

 

[Kiwi]

Re: Suzuki Primer Bulb

One more question - the primer bulb on my fuel line is at the engine end, so it sits in the well and inevitably gets wet. I was thinking of maybe placing it at the tank end of the fuel line when I reasemble it to keep it dry. Is there any problem doing that or does it have to be up near the engine ?<br />Thanks<br />Mike

 

[MIKE F]

Re: Suzuki Primer Bulb

Kiwi I'd suggest putting the primer bulb at the tank end, since access doesn't seem to be a problem. Keep it out of the weather, if possible.Just make sure it's installed in the right direction for the fuel flow.