Tohatsu 40HP TLDI Throttle Body Same as 50HP? (See Pics)

[rustnrot]

I may be installing a replacement 50 HP TLDI computer in a Tohatsu 40 TLDI engine. As you may know the only difference between the 40 TLDI and 50 TLDI is the computer (ECU) itself and also the Throttle Body.

I am posting pictures and dimensions of the 40 TLDI throttle body below to see if anyone has measured a 50 TLDI throttle body to compare to. It may be as simple as the restriction plate in the front throat of the 50 TLDI is either not there or has a larger hole in it. Or it could be a larger butterfly and bore through the casting.

FYI, the bore of the 40 TLDI throttle body itself (butterfly diameter) is 40 mm (as pictured from the rear of the throttle body). The hole in the restrictor plate is 24 mm and the outside diameter of the restrictor plate itself is 2.5 inches (as pictured from the front).

[chris3298]

So this is the what the washer looks like, my 50 TLDI doesn't have this washer. I have been curious though of why can't you bore the throttle body and put a bigger throttle plate in there. They do this with fuel injected cars. I know my jeep wrangler they sell a bored out throttle body for it, they claim in will give a few extra horses.

If my dial caliper wasn't froze up I'd check the size for ya.

Chris

[rustnrot]

So as far as you know, your 50 TLDI never came with this "washer", it wasn't removed by somebody?

When your dial caliper cooperates...

[chris3298]

mine did not come with it and as far as I know, no one removed it. Hell when i bought my motor new me and the mechanic took it out the box so no it never ever came with a washer in the throttle body. Guy name 50hptiller on youtube said he had one in his.

[rustnrot]

That's why I asked...I thought 50hptiller said his had one too. Hopefully he will see this thread.

I'm willing to bet that the only reason is there is two different part numbers for the 40 and 50 throttle bodies is that the 40 has the restrictor plate and the 50 does not. Somebody will chime in with a bore / butterfly measurement and we'll know for sure.

Definitely not gonna run out and buy a 50 throttle body without first taking out the restrictor plate and trying it, that's for sure!

BTW, your 50 throttle body still has the screen on it, correct?

[chris3298]

People have said on here before that to make it a 50 you have to change the computer out but on my part it sure would s*ck if all I had to do is buy the 40 and remove the washer and i'd have me a 50 if this were true I just wasted probably more money paying for a 50. Do have an email for a guy who works for Tohatsu in the USA but doubt he'd give me a straight answer but I'll ask and get back with ya.

Best way to get in touch with 50hptiller is to go on his youtube channel and even then it may take a bit for him to reply. Shows on here he hadn't been on the forum for a while.

Yes my throttle body has the screen on it.

Chris

[rustnrot]

Here is a link about the two different parts between the 40 and 50:

http://www.internetoutboards.com/PartDetail.asp?id=1049

Also, I noted looking through the parts manual that those are the ONLY two parts that have different numbers between the 40 and the 50 tldi engines.

[mercguy]

pretty much all the manufacturers do the same thing on all their same displacement motors...............computer (ECU/PCM, ECM, EMM, etc) and restrictor.................from what I recall, it is ALOT cheaper to buy the larger HP motor, when new, versus swapping out the parts after the fact......