1995 Rude 130hp - Compression reading?

[imtawd77]

Sorry, I have alot of questions about this engine. I just want to make sure its in excellent condition before i buy it... Anyhow, Im going to do a compression test on it tomorrow. How many LBS of compression should this engine have? Also, do you do the test with all the plugs out, and WOT? Thanks for the help!

 

[reeldutch]

Re: 1995 Rude 130hp - Compression reading?

disconect the ignition pp<br />take all plugs out<br />put lever in full trothle<br />make shure battery is fully charged<br />screw in tester and crank moter 5 revolutions on each cylinder. moter can be cold or warm.<br /><br />your readings should not be less than 100 psi and there should not be more than 15psi difference in lowest and higest cylinder.<br /><br />if you do have a reading like 95 95-90 90<br />the moter could be fine.<br />a reading like 120 120-95 -115<br />ask the seller to pull the head to take a peak inside. probbebly it has big problems.<br /><br />good luck reeldutch

 

[imtawd77]

Re: 1995 Rude 130hp - Compression reading?

So, the numbers dont actually matter as long as they are within 15-20 pounds of each other correct?

 

[reeldutch]

Re: 1995 Rude 130hp - Compression reading?

it depends,<br /><br />post the numbers and see wat you got.<br /><br />say<br />100/100<br />100/85<br />something is going on even if it is within the 15pounds.

 

[imtawd77]

Re: 1995 Rude 130hp - Compression reading?

I will take the compression readings tomorrow and will post... Thanks for the help!!

 

[imtawd77]

Re: 1995 Rude 130hp - Compression reading?

Ok, at wide open throttle here were the compression readings<br />129lbs<br />130lbs<br />129lbs<br />132lbs<br /><br />Let me know what you all think of those reading. Motor still in good shape? Thanks alot!

 

[Frank I.]

Re: 1995 Rude 130hp - Compression reading?

Thats about as good as it gets,good luck!

 

[imtawd77]

Re: 1995 Rude 130hp - Compression reading?

is there any way to judge how many hours the motor may have based on the compression results? The boat the motor came from had no hour meter. Thanks

 

[Brew2]

Re: 1995 Rude 130hp - Compression reading?

Not that I'm aware of....doesn't really matter anyway as a well maintained motor with hundreds of hours on it will be in better shape than a mistreated motor wtih a fraction of the hours.<br /><br />Those compression readings look great, so whoever currently owns it likely has taken care of it.<br /><br />Good luck!

 

[rodbolt]

Re: 1995 Rude 130hp - Compression reading?

the 100 psi number may or may not be correct. the early 90's 200 loopers only showed about 80 psi new. the key is less than 10 psi difference between them. anything more and its time for a leakdown test.be aware that on jonny rudes you compare cylinders on a bank not like yams which compare bank to bank. on the v4 loopers its not uncommon for say 90 psi on the port bank and 80 on the stbd. all a compression test is is a quick test of the cylinders ability to seal. nothing more. a leak down test takes 30 min more but is much more accurate.

 

[imtawd77]

Re: 1995 Rude 130hp - Compression reading?

I bought it before taking the compression readings because there was another guy that was really interested in the motor. So, I guess I got lucky and got a great motor. The crappy part is, I hung the motor on my boat and my transom is sagging bad, and the aluminum side of the boat is cracking from the weight. I was really happy to find an aluminum boat that was rated for that much power as im not a fan of fiberglass boats. So, the boats junk and my chances of finding another is pretty slim. I can either sell off the motor, or keep it around and hope i come across another high horsepower aluminum boat. Thanks, I appreciate all the help you guys have been!

 

[imtawd77]

Re: 1995 Rude 130hp - Compression reading?

I listed the number top left, top right, lower left, lower right. so it was<br />top left 129lbs (looking from the back of the motor)<br />bottom left 129lbs<br />top right 130lbs<br />bottom right 132lbs<br /><br />I did the test with all coils unplugged,all plugs out, with the throttle wide open and cranking the motor with a jumper wire on the cylinoid.

 

[G DANE]

Re: 1995 Rude 130hp - Compression reading?

Compression is great, as good as it gets. That must be a low hour motor, or it is in shape like one. If you like the boat, the transom issue is fixable as long as the motor HP is within the boats range. Go to the Boat Restoration and building forum and od a search on transom replacement/repair. Its much easyer on an aluminium boat than on a Glassfiber. There are great pictures from people that restored both.

 

[imtawd77]

Re: 1995 Rude 130hp - Compression reading?

I would like to fix the boat but I already have another boat thats my project. This boat would need a new transom, and quite a bit of aluminum welded where its cracking. I wish i would have looked at the boat a little better before I bought it. Oh well... Maybe I will get lucky and find another high horsepower aluminum boat thats in a little better shape. Thanks guys, I appreciate the help!!