Yamaha 130 V4 Project Build.

**Mr. Demeanor** · 08-01-2015, 01:29 PM

Originally Posted by hydro

I have a least 6 available.

Sent you an email. Thanks

**chris3198** · 08-30-2015, 10:28 PM

Reading through old post trying to catch up been a while since i have followed this thread, what I'm about to ask is probably seriously costly but guess you never know. So the cracked case problem you have is there any chance to have one made out of billet aluminum rather then cast?? or would this end up costing you ten's of thousands of dollars to have made and would it be that much stronger? i ask because i have seen some crazy looking racing lower units before and they look to be made out of some kinda billet aluminum.

Congrats on over 97 mph seems like last I hear it was like 95 you were at.

**Mr. Demeanor** · 12-02-2015, 02:23 PM

Whats new Yamaha peeps?
Nothing here.....
Havnet run the boat in quite awhile.

**Mr. Demeanor** · 01-22-2016, 11:45 AM

Just a little update. NOt much went on over the summer and fall. Finally got some good air here. Pulled the cover off last weekened and checked the piston wash and it was really rich. Raising the ex ports definitely made it run fat. I went down a couple jet sizes and it seems to have cleaned up and really woke up. Ran 91mph at 7060rpm with the my slowest prop. Thats a couple mph faster.

I still think my super long tuner is not letting the raised ex ports work. Talked to the boys at Hydrotec who thought that could also be the case. I had already cut 3/4" off when I went to the short mid because it was hitting inside the lower unit which wouldnt fit up.
Yesterday I took an inch off making it flush with the bottom of the mid section. I didnt notice any loss of low end power when I cut it the first time and hopefully this cut wont kill my bottom end and will let her eat up top.

Running the boat on Sunday so I should have a good idea of how it changes the power band.

**FMP** · 01-22-2016, 12:06 PM

The tuner for the V4 , is it a single or split for both sides. Wondering how they did the pulse tuning on it.I haven't seen one apart, so don't know if its a tuned pair or how the chest is.

**Mr. Demeanor** · 01-22-2016, 12:21 PM

Originally Posted by FMP

The tuner for the V4 , is it a single or split for both sides. Wondering how they did the pulse tuning on it.I haven't seen one apart, so don't know if its a tuned pair or how the chest is.

Its split at the top then opens into one chamber a few inched down if I recall.....

**DoktorC** · 01-22-2016, 12:26 PM

Any thought of trying a short V6 tuner?

**Mr. Demeanor** · 01-22-2016, 12:28 PM

Originally Posted by DoktorC

Any thought of trying a short V6 tuner?

The guys at Hydrotec gave me stats on different tuner lengths. If you go too short it just kills the bottom end and im swinging big props. I m worried about breaking the prop loose to get up on plane.

**Mr. Demeanor** · 01-22-2016, 12:29 PM

Originally Posted by FMP

The tuner for the V4 , is it a single or split for both sides. Wondering how they did the pulse tuning on it.I haven't seen one apart, so don't know if its a tuned pair or how the chest is.

Found some pics in this thread. I did plug the relief holes in the top of the tuner.
http://www.screamandfly.com/showthre...amaha-V4-tuner

**DoktorC** · 01-22-2016, 12:39 PM

I still think a v6 tuner would be worth a try...even a longer Vmax200 version. That has got to be killing you top end or at least your potential to rev an take full advantage of your porting.

**FMP** · 01-22-2016, 12:44 PM

Is ex chest split side from side then split plate ? LS/RS ex chest ?

**Mr. Demeanor** · 01-22-2016, 12:44 PM

Might be worth a shot. Lets see what this one does and Ill decide if I want to go any faster

I still need to try the 115 exhaust chest plate as well. To me it looks like it would flow better. There may be a sweet spot with a combo of the right tuner and chest plate.