Yamaha/hydro-tec, Help With Bog.

[FAST-J]

I have a 96 pro-v 150, last year I installed tuner, exaust plate, heads,reeds, mod air box and jetted up, I decided to go with the mod intake and reed plate, also went from 32mm carbs to 34mm carbs, Here is the problem, hole shot is great, mid range is ok as long as I don't punch it, when I do go full throt:confused: tle it seems to bog, I let off to around 3/4 power and the boat will pick up speed, I have checked everything, This is the set up hydro-tec said to do, does it sound like I have to much carb now? Please help, this is making me go nuts, Thanks.

[Fast Fred]

i'm thinkin jets.

[FAST-J]

do you think to much?

[FAST-J]

to much or to little?

[Little Jon]

if theyare bogging it would be toomuch

[Fast Fred]

sounds like it mite be too fat, them jets are in metric, that bump by 5, like 160 next size is 165 , check the burn on the plug and look in at the crown of the piston.if it dark bump down one size. check the burn first then go from thare,:cool:

[FAST-J]

just went and looked, piston is black, plugs are new, but are black inside, porcelan is a little black on one side, i drilled the jets out using a 51 size for the 170mm and 50 for the 178mm size , hydro-tec said, to use a 176mm but all I could find was the 50 size bit that is supposed to be a 178mm, they said it should be fine, what do you think?

[Fast Fred]

170's, have some 165's reddy:cool:

[FAST-J]

I have 165's but thanks. only two cylenders have 170mm, the others have 178mm I wonder if I should go 170mm all the way around? I think when you drill a jet out, it is bigger than what is in intended.

[Fast Fred]

i find that a torch tip cleaner works the best for over sizein jets, i'd go a bit fat,
you can always lean on it more, like 172's see how she responds:cool:

[FAST-J]

Thanks fast fred, I am now on a mission, I hate to do it but it looks like I will be lake testing on easter, afternoon of course. Thanks, Jay

[hydro-cat]

Call Hydro-Tec. See what they have to say. they are very easy to deal with and usally are right on.

Tim

[FAST-J]

Hey Tim, Yes your right, But I can't wait till monday to talk to nathan, It's killing me to get this problem resolved today, because I want to try it sunday, I have already went down on jet size, just finished up a few minutes ago, so far everything that I have bought from them has been right on the money, I just installed intake and carbs friday, I guess you might say I am one of those guys that just has to getter done! haha! Thanks, Jay

[espen]

Maybe check the diagrams in the fuel pumps if they are leaking , there is a glue in the pumps to secure the screws inside the pump , sometimes this comes loose and blocks the carb fuel inlet .
Take of the air box and check if same amount of fuel spraying out of each carb. If you use a spray bottle with fuel you can pour some into each carb and see if it picks up power.A easy way of checking if all cylinders are playing is to cut the ignition and rush back of the engine and feel the heat on each isolator on the sparkplugs, if the temp are even all cyl are working.

[hydro-cat]

Instead of asking for Nathan, see if you can talk to John. He is the guru behind alot of there stuff


Tim

[Ray Neudecker]

What is your timing set at? The jetting sounds close enough to work without those symptoms. It actually sounds like a fuel resticton. The fuel pumps at their best are marginal on this type setup. It has been my practice to replace with a good electric pump with a regulator set at 5 1/2 to 6lbs.
Did you rebuild the carbs including new bowl gaskets?

[Fast Fred]

piston is black, plugs are new, but are black inside,
:eek:

[espen]

Hi ! Check if the timing does follow the trottle movements , if the trigger plate are stuck or link are missing or broken you have to little advance at high rpms.

[FAST-J]

Thats the first thing I checked, I even made sure the timing is correct, I went down to 173's on 1,3,5,and 6, I left 2 and 4 alone to see what kind of diffrence it would make, I test ran today, I have no more bog but it is still way to rich and have lost 4mph, I should have picked up 1 or 2 mph, I guess I will find out monday from hydro-tec what the problem is, this set up calls for 170's on 2 and 4 and 176's on 1,3,5,and 6. Thanks for the advice, Jay

[FAST-J]

What is your timing set at? The jetting sounds close enough to work without those symptoms. It actually sounds like a fuel resticton. The fuel pumps at their best are marginal on this type setup. It has been my practice to replace with a good electric pump with a regulator set at 5 1/2 to 6lbs.
Did you rebuild the carbs including new bowl gaskets?
Hey Ray, timming is dead on at 22, I did jet down and bog is gone but still to rich, all plugs are blacker and so are pistons, I checked fuel and there is no restrictions, I just replaced pumps 2 months ago, the carbs are hardly used, needles and gaskets looked fine for re-use. Thanks, Jay

[Fast Fred]

Lean on it:cool:

[Ray Neudecker]

Never reuse the bowl gaskets on a Yamaha carb. They have a tendency to start coming apart over time and intermittently sticking the needles. I would think the timing would need to be 24 degrees on the horizantal motor for best performance. Remember though that increased timing may call for more fuel. Only try one change at a time here and monitor plugs.

[FAST-J]

Hey Ray, I am taking your advice and have ordered 3 new gaskets, do you know about boats.net?, 20% off msrp every day to anyone. I talked to john at hydro-tec today, heres the problem , this setup has never been tested with the 34mm carbs that they said use, thats why i'm to rich, set up has only been tested with 32mm carbs, (go figure) john said to drill out the air bleeds on top of the carbs with a 32 bit, (150 hp carbs have larger air bleed than the 200's, this is why it is to rich with the jets they said use), if thats not enough try a 31 bit, (now i'm a ginnie pig) so i used the 32 today and tested, no bog but still lost a lot of power, I will follow up tuesday with john, I will keep you posted, Thanks Jay

[FAST-J]

Hey Ray, Well I'm going back with my original 150 carbs and new bowl gaskets, I want to see if I have an intake problem or what, I think hydro-tec has sold me an intake that they did not modify, why do I say that? Just something John had said, and for some reason they offered to give me my money back on everything today, something does not add up, but I may be wrong, I will find out I guess. Jay

[Ray Neudecker]

Not sure what the problem is, but they are certainly being more than fair with that offer. The problem you described has been disscused before. I made suggestions to help to posters here and never heard anymore from them. Really don't know if the suggestions cured the problem but have to go by the no news is good news in those cases.

[FAST-J]

Yes Ray you are right, But when you buy something from them, You are paying for the r&d without the guess work.

[FAST-J]

Thanks Joe, Do you think you could have him contact me? either here or my cell 662/719-1653 Thanks, Jay

[Ray Neudecker]

If he can help that is fine, but you are working with two different motors. Chuck's was a vertical front half 150 and Jays is a horizantal front but not the same as the Excell one.
That model very good results for me came with the tuner and adapter plate, increasing the jetting to 165 and the timing to 24-26 degrees. Never put the hot heads on one or bothered with the intake on them. I wouldn't have considered using the stock fuel pumps with those mods added.

[FAST-J]

Ray is right, mine is the horizontal, 1996. I have already removed the 34mm carbs this afternoon and got my new carb gaskets in today also, now just waiting on my 32mm carbs to come back from hydro-tec, should be here thursday, if all goes well I will test run thursday afternoon, with the jets they say to run, I will let you guys know the results. Thanks, Jay

[espen]

maybe you should have some bored out carbs ,36 mm. bore it out and have them set up the jetting....

[FAST-J]

Well guys, Here is the results, I put the 32mm carbs back on with the jets they said to use with the mod intake, could barely do 70mph, thats still a loss of 7mph, called john and he said he did'nt know what else do but to go back with my stock intake, so I did, went back to my original setup and back to the lake I went, I am glad to say she is back strong again and will be sending the intake back for a full refund. I just want to say, Thanks for all the input, Now I am going to enjoy life again! Thanks again, Jay

[Chuck_Nj]

Jay pleasure chatting with you today glad to see at least you can sleep again !!!

[FAST-J]

Hey Chuck, Same here. Well here is some new news, When I was taking apart my nightmare yesterday, I noticed that the gasket was'nt straight in the intake, there is a channel between each port and the gasket looked to be restricting this channel, so before the intake made the trip back to hydro-tec, I decided to call John, He said they always cut that part out with a razor blade, this more than likely exsplains why I was to rich using the 32 and 34mm carbs, it was like running a stock intake, So I have decided to give it one more shot, But not right away, I need a break for now, john is sending me another gasket and some jets, wish me luck. Jay

[Dingie 2]

Fast-J , I have been following your post from the start being that I have many dealings with HydroTec and have been pleased with all the parts that I have bought and that I am always interested in any Yamaha performance gains. How I am understanding your post on the forum the root cause of your problem was do to the fact that the intake gasket wasn't installed correct and wasnt a part problem ?(is this correct ) So far I have had good luck dealing with Nathan,John and Gary at HydroTec . When I buy a part or assembly from them I am paying for over 15 years of R&D . HydroTec has been with Yamaha since the beginning of thier entry into the US market. After you find the exact cause of your fault please do a follow up post to let us know what was the cause of your MPH lose.I try not to ever miss any post that talks about Yamaha Performance.It is always nice to hear what the final fix was to a problem. Thanks Joe Raimondo

[FAST-J]

Yes the gasket was installed correctly, it will only go one way, it's either right or not at all,the problem is this, there is a channel between each port, the gasket was sucked down into these channels causing a restriction, John said they always cut out the gasket to prevent this, I was not told this until after I removed the intake and called john about the problem, john has been good as gold helping me with this problem, when I said it was not straight, I ment the sag were it was inside the channel. I don't want you to think I am doging out hydro tec, because i'm not, this is just a small issue that we are working out to solve my problem, I use them for one reason, I TRUST in what they do. Jay

[FAST-J]

Well guys, I have good news, I cut the little 1/8 inch wide x 1 1/4inch strip out and put her back together,everything is the same, this is the only change made, it's is amazing the diffrence it made, I ran the 32mm carbs today with the jets they said to run, it is still a little fat, but I can deal with that prolem being its a lot closer now to being right. Lake conditions today were not what I would prefer, it was flat, I mean flat smooth, no wind, 75 degrees and high humidity, (thats mississippi for you) but it ran very well, now I will try out the 34mm carbs and maybe the wind will pick up. I will keep you guys posted. Thanks, Jay

[FAST-J]

Dingie2, What motor and year do you have?

[FAST-J]

Wow! Sounds like you have a hot V-4, Well I wanted to do the 34mm carbs today but I have a 28 trophy that I have to balance and blueprint and get shipped back out tomorrow, I will do it thursday and let you guys know the results. Jay

[FAST-J]

Heres the final, I installed 34mm carbs with same jets as 32mm carbs, now keep in mind the 34's have been drilled out in the top air bleeds to a 32 size bit to lean them out, they ran very well yesterday, now I need to work on my prop a little, for some reason the extra power is giving me way to much lift, I have never seen this happen, sounds crazy, but true, the motor is still tucked, I will re-work prop today and re-run this afternoon, stay tuned! Jay

[Dingie 2]

Fast -J. Jay I couldn't help but notice that you do prop work. I have a question that you may be able to help with. I water tested my new ported power head today .It is not broke in yet I have 2-3 hours on it. The power band has moved up and when I first hit the throttle it doen't snap out of the hole as well as I am used to. It takes a second to get the RPM up than it goes like hell.The prop that I am running has 3/8 vented holes if I drill these holes out to 1/2 inch will it help me spin this thing up without hurting anything else ? Joe Raimondo

[FAST-J]

Dingie 2, Yes it would make it spin up quicker, but be aware, to much hole may make it blow out, if it is a 4 blade, try just drilling 2 holes out, 2 straight across from each other, if still not enough drill out the other two, if it does blow out after all this, you can always weld them back up and re-drill, I would start with a bit between the 3/8 and 1/2inch. Well i'm still a little fat on my jets, I re-jetted today but have not ran yet, maybe tomorrow afternoon. yes I do work on props 12 years worth, but not my day job, I do everything except replacing hubs, I do blueprint, balance, polish you name it, nathan at hydrotec is supposed to send me a prop to see how he likes my work. Jay

[Dingie 2]

Jay , To late Im always in a hurry .I it's a 3 blade, I drilled the holes to 1/2 inch a hour ago. If its to much I will have to have it welded. I will find out in the morning. Good luck with your jets. Read them piston tops and dont run it to lean. Joe Raimondo

[FAST-J]

Hey thats what scares me, i'm not a pro at plug reading, but with a short 2 mile run they sure got black, i'm only going down one size, two are 170's to a 165 and four are 176 to a 170 what do you think? Jay

[Dingie 2]

Jay, You are better off reading the piston tops. You can get a false reading on plugs that are not new. Make a WOT run and shut it down at WOT dont back off first ,after the WOT pull the plugs get a small LED lamp and look into the cylinder. Prof. OB had a really good post on reading piston tops do a search and see if its still there.Dont trust those used plug readings. Joe R

[FAST-J]

I cleaned the plugs before I ran with an air powered abrasive cleaner, so they were like new as far as being clean, and still got black, I will check on that post. Thanks, Jay