Compression on Tohatsu 50 TLDI?

[wetwaterman]

What compression is "normal" on Tohatsu 50 TLDI?<br />The engine has run 75-100 hours.<br />Test gives 100psi over all cyl.<br />It's even, but okey ? To low?<br />Maybe TLDI's working whid lower compression?<br />Thanks in advance for the feedback! (if,I hope)

 

[TOHATSU GURU]

Re: Compression on Tohatsu 50 TLDI?

120 PSI is where it should be, but different gauges will give you different readings....100 PSI would cause me a little concern. Your gauge would have to be really off or the engine has a problem.

 

[wetwaterman]

Re: Compression on Tohatsu 50 TLDI?

Thanks for the answer. I have trying different<br />guages...but the redings in the same. It's a test on a angine for sale...maybe I should looking for something else.

 

[wetwaterman]

Re: Compression on Tohatsu 50 TLDI?

I'm back again.<br />That value "120 PSI" ...have you get it from the specific svmanuel for this specific engine?<br />(important if I hawe to argument with the owner)

 

[ziemann]

Re: Compression on Tohatsu 50 TLDI?

More important is whether the compression readings are consistant across all cylinders. It sounds like they are the same. I am probably less concerned than Elvin on this. <br /><br />Elvin is correct- 120 psi is the correct value on compression- but note that this is for a warmed up engine. <br /><br />If there is more than a 14-15 psi spread in the compression between the cylinders, then you should be concerned. <br /><br />Have the dealer run the engine for you if that is possible. The TLDI's have been extremely reliable. <br /><br />By the way, all of these numbers did come from a manual for a TLDI 40B/50B.

 

[wetwaterman]

Re: Compression on Tohatsu 50 TLDI?

Thanks, god to know that the numbers come from<br />the manuel. This engine is 50A. Hmm...what's the differece between A-B ?<br /><br />The dealer and I have run the engine. It's start and run calm in low rpm. Maybe it was some smal<br />"klank" sound? (piston against cyl.vales?)<br /><br />I think I have to take the motor to profesionell deales for "ear" and a further comp.test. <br /><br />The big question is how can the engine lose<br />from 120psi to 100psi.... on 75-100 hours?!<br />...as the dealer says it have run? I think it's some smoke in his story.

 

[ziemann]

Re: Compression on Tohatsu 50 TLDI?

With a TLDI, you are going to hear a distinctive yet subtle ticking of the injector system. That sound is normal that you are probably hearing. I would again check the compression after the engine is warmed up. Maybe use a couple of compression testers as Elvin suggested to check accuracy of the gauge. Again, if all cylinders are even, personally, I wouldn't be too scared of this unit. Consider having the dealer put a guarentee on this motor (like 30 days) just to be sure. If there is truely a problem it will likely show up right away.

 

[wetwaterman]

Re: Compression on Tohatsu 50 TLDI?

Thank's for great respons!...in Swedish boatforums I get no answers? The owner have put a 6 months guarentee on this motor . But even if a Tohatsu is worn...I dont think it breakdown in 6 months.But maybe I have a very weak engine earlier and much earlier repair than normal? Yes the ticking was there...charming...but it was not regular?...now and then.

 

[khc1970]

Re: Compression on Tohatsu 50 TLDI?

The A engine was the first engine came out from Tohatsu, there were a few minor problems, like engine not coming out of break in mode and mapping (?) and the B engine are the present engines with the problems sorted out. Having said that, the problem associated with the A engine is relatively small number of engine affected.

 

[wetwaterman]

Re: Compression on Tohatsu 50 TLDI?

Thanks for answer but my english are not so good...sorry.I don't understand... "like engine not coming out of break in mode and mapping"?

 

[TOHATSU GURU]

Re: Compression on Tohatsu 50 TLDI?

The electronic contol box on the A would not always adjust the RPM as it was supposed to. The B module has slightly different operating parameters that eliminated that rare problem.