Nissa 40C

[Gamble]

Guys, new to the forum, but this seems very informative, and I hope to seek someone's help! I have a 1988 Nissan 40C. Did carb job, replaced spark plugs, currently running ngk, but have tried champion.

Problem, is that engine stumbles when coming off idle. New plugs seemed to have fixed this, however at 3500-3800 rpms, it misses every now and then. Compression is 120 in both. checked fuel filters, all seem fine. I've mixed some sea foam in the 6 gallon tank now, and haven't run much through yet. Any ideas on what could be wrong? Also, what gap should I be runnin on the plugs. I think the ones in there now are ngkbp7hs....or something to that effect. I spoke to the folks at tohatsu and they recommended these due them being a hotter plug. I have them gapped at .45 now. I'm just trying to eliminate all the possibilities

 

[TOHATSU GURU]

Re: Nissa 40C

It's always been the BP7HS-10 plug for that model and they should be gapped at .39. Since you have even compession and hopefully have already done all of your electrical tests, that leaves fuel, which puts you back at the carburetor and or reeds.

 

[Gamble]

Re: Nissan 40C

Re: Nissan 40C

Guru, thanks for the help........those ngk plugs are what I'm running.....how hard are the reeds to replace? I ran it today and it seemed to run better. Still stumbled off idle right when I first took it out, then it ran fine the rest of the morning. A miss or two around 3500 rpms but other than that ran great. I'm also wondering if I might have some trash in the carb that may eventually run its way out.

 

[TOHATSU GURU]

Re: Nissa 40C

They are easy to get to, but you would only replace them if one has chipped...And that almost never happens.

 

[Gamble]

Re: Nissan 40C---Parts/part numbers needed

Re: Nissan 40C---Parts/part numbers needed

Elvin, thanks for all your help.......today it ran as good as it's ever run,....I think I just need to keep pushing some good fuel/some sea foam through the carb and get it cleaned out, hopefully whatever trash is in it will pass through it. I also think the reeds are good, it runs too good for them to be messed up. I'm in need of the blue paint that covers the entire motor and the gasket that goes around the cowling. Any ideas where I could get them, or the part numbers? It's a 1988 NS40C.

 

[TOHATSU GURU]

Re: Nissa 40C

The blue paint is available from any Nissan or Tohatsu dealer.