OUTLAW EAGLE MANUFACTURING

bonecracker · Joined: 09 May 2006 Posts: 20 Location: the big smoke

Hi there, I asked this questions on the old style forum without any luck but I'm hoping someone can help me this time. I've got a 16' Lynx with an engine question.
Has anybody got any info on getting more rpm's out of the 175? I am jetted down 2 sizes with reeds but want more rpm's. I seem to be losing rpm's each year, comparing rebuilt impeller rpm speeds, each time I rebuild my impeller and bore my sleeve. I'm still within spec at 5150 rpm but I want more! The bore is probably 20thou larger than stock but even with a worn impeller I don't get much higher than 5250rpm.
These engines should be capable of way higher rpm's.

Gator · Posted: Wed May 10, 2006 2:28 am Post subject:

The only way I know of getting higher rpm's is to restructure your power curve or change your power to weight ratio. The 175, 200, and 240 are all the same block but they have made power changes such as cam, injectors, timing, exhaust etc to get the extra hp and revs. What you are looking at doing may be more cost efficient to go with a different engine like the 240 sj. I don't know if the following info will help but here goes anyway. I was having some problems with my ob jet and ended up re-sinking (sp) the carbs and double checking the timing. I also had the carbs pulled down and checked and cleaned to the tune of a few hundred US $$$.I did not gain any rpms but I did gain some power. If you are having problems loosing a few rpm's each year you might be getting some varnish built up in your carbs or they could be out of sink (sp) a little bit. The engine was built to handle a certain rpm's, disgusting isn't it, but without doing some modifications the gain you want may not be reached without kicking out some major $$$$. I have been that route with my current engine and I have finally had to settle for what I have. Like you I want more revs and my last shot is doing some valve replacements. One other thing I forgot was the leading edge on your pump has to be at the right angel, I reversed mine and screwed up the whole shebang till I got it figured out. Good luck in your venture, and I wish you success.

Gator

bonecracker · Joined: 09 May 2006 Posts: 20 Location: the big smoke

Thanks for the reply Gator! I totally agree with what you are saying. The only problem is I'm looking at >6000$ with my motor/pump trade for 70hp extra! The worst thing is that I'm considering it!
I just cleaned, reset floats, synced(sp) my carbs. I advanced my timing a little and all this did was get me 5200-5250rpm. I had hoped to find info on the rev limiter or some sort of tuner to bump the rpm's up a little but there is very little on sportjet's! Mercury 2.5 outboards rev as high as 10000 rpm (with mods) so I figure a thousand or so more wouldn't hurt.
I love these 175's. They are bionic and easy to wrench on. If only I had an Outlaw Lynx that performs like an Eagle Shocked

then I would be happy-----. If only that easy.------------Come to think of it I would probably have to have started this thread as; Eagle Lynx more rpm's.

Akgravelpumper · Joined: 26 Apr 2006 Posts: 22

Getting more rpms from a two stroke takes a little more than jets or reeds, is your motor turning the same R's as new? no? if not a compression test or better yet a leakdown test is in order. Are your aftermarket reeds still in good shape, some may gain performance or make the motor a little more crisp but sometimes might not be as durable as stock reeds. If your motor is turning the same r's as new getting an extra 1000 rpms will be a challenge, your motor is designed to make power in a certain rpm range, this is determined mainly by port timing (the location of intake and exhaust ports in the cylinders) unlike just changing a cam in a four stroke changing port timing involves grinding of your clyinders or "porting". OK say now you had your motor ported by someone who knows porting now there are aftermarket fuel injection controllers that will work with this motor, also the timing must be modified and maybe some work on the head ect.now ... your turning say 7200 rpm 260 hp (random numbers) now you need an impeller matched to your combo not really a large selection available so it must be custom. turning a stock impeller at those speeds would likely require much more hp than my example. maybe you could come up with the right combo of gears in the pump. anyhow I guess all I was trying to say is it would take alot of work and $ to run rpms significantly higher than stock
The motor and pump combo are designed very well as a package but mods are not as easy as on a prop boat were you can change prop pitch or even a berkley style pump were you have a selection of impellers. enough rambling from me

Akgravelpumper · Joined: 26 Apr 2006 Posts: 22

Getting more rpms from a two stroke takes a little more than jets or reeds, is your motor turning the same R's as new? no? if not a compression test or better yet a leakdown test is in order. Are your aftermarket reeds still in good shape, some may gain performance or make the motor a little more crisp but sometimes might not be as durable as stock reeds. If your motor is turning the same r's as new getting an extra 1000 rpms will be a challenge, your motor is designed to make power in a certain rpm range, this is determined mainly by port timing (the location of intake and exhaust ports in the cylinders) unlike just changing a cam in a four stroke changing port timing involves grinding of your clyinders or "porting". OK say now you had your motor ported by someone who knows porting now there are aftermarket fuel injection controllers that will work with this motor, also the timing must be modified and maybe some work on the head ect.now ... your turning say 7200 rpm 260 hp (random numbers) now you need an impeller matched to your combo not really a large selection available so it must be custom. turning a stock impeller at those speeds would likely require much more hp than my example. maybe you could come up with the right combo of gears in the pump. anyhow I guess all I was trying to say is it would take alot of work and $ to run rpms significantly higher than stock
The motor and pump combo are designed very well as a package but mods are not as easy as on a prop boat were you can change prop pitch or even a berkley style pump were you have a selection of impellers. enough rambling from me

Gator · Posted: Wed May 10, 2006 12:52 pm Post subject:

I understand the situation you are facing, I was looking at several grand for a larger engine myself. The were a few things that stopped me with money being the the main factor, second was the extra lbs hanging off the back of my boat which could change my ride and the the last thing was the speed and horse power I was gaining did not match the out go of $$$ I was looking at. I even considered rebuilding my engine as it was the same block as the bigger engine. I do have a sputter problem that is going to require new reed valves and after that I am leaving well enough alone. The best way for me to get the extra speed is to put on a screw (prop) and that isn't happening. Dollar vs pony power says I leave well enough alone. I have a merc 115/80 ob jet and I staying there and using the money saved for Gaaasssss.

Akgravelpumper · Joined: 26 Apr 2006 Posts: 22

Bonecracker

be careful about advancing the timing too much nothing will destroy a two stroke like detonation

bonecracker · Joined: 09 May 2006 Posts: 20 Location: the big smoke

Thanks guys, I appreciate the input!

G~FORCE · Joined: 18 Mar 2006 Posts: 75 Location: OREGON

what about nitrous? anybody do that on two strokes? might be cheap and fun without the extra gas consumption during the cruise home.

oh ya gator, i think you were looking for "sync" as in syncro and synchronize
anybody seen my stapler?

Gator · Posted: Wed May 10, 2006 8:20 pm Post subject:

G Force

You are 100% correct on that aspect, it is what I was looking for but with the way the mind is working I could not come up with the right spelling or anything that looked close so I used what I had in the ol tool bag. Even with the (sp) behind, hopefully some were able to correlate to what I was trying to expound upon. Now that the fun is over, thanks for the info because I really was dumbfounded about how to get the idea across and I really had no clue that it was sync. Again thank you. Unfortunate as it may be I am like the MAD CLOWN, at one time I was at peak performance and running strong now I am on the bottom and every thing I was is lost to all.

G~FORCE · Joined: 18 Mar 2006 Posts: 75 Location: OREGON

no problem, just dont let it happen again.

G~FORCE · Joined: 18 Mar 2006 Posts: 75 Location: OREGON

by the way nice use of expound!

Gator · Posted: Thu May 11, 2006 2:05 am Post subject:

Thank you for that emboldened compliment on my efficacious verbiage. During my formative years I always tried to slip in one speculative word that had to be looked up to make sure of its sui generis. However my communications instructor suggested using more compliant words and not writing at such a level that nobody could understand with out the use of a webster, I will do my best not to make such an eloquent mistake again. ;-o

Gator

Now may I put a way my American Heritage Second College Dictionary, thesaurus and Scrabble Players Dictionary.