Repower 2004 AR210 with MR-1 HO's

[84rzv500r]

replaced the switches for the under water lights, auto bilge, and Radio's.... LED's burnt out on radio and bilge... underwater lights the ground spade terminal corroded and fell off... problems solved...

 

[84rzv500r]

ok sea trials today plan on filling in the rest of this chart over the next couple days...

155mm pumps and Solas 12/18's

RPM GPS Speed (MPH)
1650 4
5000 32
6000
7000
8000
9000
WFO

 

[84rzv500r]

well so much for these being miserly engines.. port engine started skipping on the way home last night...it just died doing the drop cylinder test...

mind you i put 20 gal in when I started this mess and I put 5 gallon more in yesterday before i headed out...

I checked the the fuel pressure and I only had 20 psi, I put 10 gallons in cycled the fuel pump a couple times till i got 50 psi on the needle and it runs perfectly...

should be able to run them up to full throttle for a couple bursts today... the two strokes were pretty mild until they came on the pipe round 4000 the MR-1's seem much more linear...

 

[Greg Christenson]

Just binge read this entire thread. Great work! Thanks for sharing your experience and detailed posts.

 

[84rzv500r]

ok I need more impeller... couple of quick bursts up tp 10,200 they were effortless. but resulted in 47 MPH I have 12/18's now I will go to 22mm shafts and 11/20's. they are in the spares pile... along with new bearings and seals and longer alloy tailcones... ambition lacking LOL

On a side note the ride quality has improved a ton... I have like 40 gal of fuel in the ski locker tank and it just punches through the waves... prolly costing me a little top speed but its well worth it...

and the LiFePO4 batteries are amazing... 10 hours yesterday on the house batteries and hardly touched the capacity and they charge up so quickly

 

[84rzv500r]

ok 4 full days on the boat and no operational issues at all... used 30 gal of fuel. It was pretty gusty on sunday on the way home and i ripped the rear seam on my original bimini canvas.. headed to west marine today to pick up a stick of 1" and 7/8" tube and Ill raise the bimini and move it forward ever so slightly... Its always been to low and cant stand up fully underneath it and moving the bench seat forward makes it a little tight getting onto the rear deck...

i just cant get over how smooth and quiet these engines are... compared to the two strokes...

 

[84rzv500r]

ok time for an update... I been running the boat nearly every day since before Memorial Day.

• LiFePO4 batteries are in the really really like column...
• the MR-1's are way better on fuel than the 135 two strokes
• Moving the CG slightly forward with the Ski Locker fuel tank GREATLY improved the RIDE and the feel of the boat however, even loosing almost 200 lbs of weight net I gave up prolly 2-3 MPH on top...
• I need to swap the impellers as I hit 48-49 MPH at about 9500 RPM (which is about where the 135s would turn 6500) flying the Bimini with 40 gal of fuel in the tank... If I push the throttles forward I have more power and it the engines rev right up to 10,500 however i only pick up another 1 MPH. it feels maybe I'm spinning the impellers too fast and is cavitating Its like Im stuck in low gear with 12/18's so im gonna try some 11/20's that I have and I have more impeller choices with 22mm shafts anyway...
• all that said and done my main design goals of better ride at cruise, better fuel economy, quiet smooth and not stinky engines, not giving up any shallow water capability, no fuss no muss stating, and better alternator output have all been reached..
• would Like to have 60 MPH on top? yep but Im beginning to think that even with SVHO's and 160mm pumps its not worth it..

 

[84rzv500r]

oh and I adjusted the idle to 1850 RPM from 1650 on each side and that gives me 4.5MPH no wake speed....

 

[84rzv500r]

today i discovered a little bearing growl in the pump or mid bearing on the stbd side checked the impeller clearance at <15 thou both sides no scoring or signs of cavitation burns and the pump stators are not chewed up... UGG its always something... time to gather up all the parts to rebuild the mid bearings and pumps and switch to the 22mm shafts... Im gonna check the hours this week but Im guessing i have 20 hours on the MR-1's... pumps have over 1000 hours on them, mid bearings with two strokes lasted between 200-400 hours... I have a few in stock ready to go, shafts, impellers, bearings, seals and orings, flanges rubbers and short shafts too...

 

[84rzv500r]

stbd engine all the sudden wouldn't rev past 9500... two issues #4 plug was miss behaving and fuel pressure under WOT was falling off to about 38-39 PSI... I could tell by the engine feeling soft after about 9000 so I bumped the idle fuel pressure to 52 PSI and she holds 50 PSI WOT and all is well.... it doesn't go any faster but it spins up LOL

these engines are Very sensitive to spark plugs...has anybody tried platinum or iridium or gone one heat range hotter in the standard plugs?

 

[Scottintexas]

iridiums used to be the go to suggestion for the mr1, then with people changing them every year/two fearing the #3 frozen plug many went back to standards,


.

 

[84rzv500r]

im gonna try them CR9EIX NGK has some guidance on the gap as it is different than CR9EB... also it appears that the market has counterfeit NGK plugs out there as well LOL....

but first after after looking at every plug I have replaced they are dry fouled and dark so NGK recommends one heat range hotter so I just ordered 12 CR8EB standard nickel plugs to try... one heat range hotter... i typically run idle or 7-8000 RPM not much in between... ill do a plug chop and see what they look like...

 

[84rzv500r]

waiting for the sunshine today... I'll have 25 hours on the repower at the end of the month... be time to change the oil and filters, and put my hotter plugs in... these motors seem to run a tad on the rich side compared to my seadoo 4 Tec as the seadoo is doggy lean and wont idle below 1800

the 32 at 5000 RPM i saw early on was 5 gal of fuel no bimini and none of the normal stuff in the boat and just me aboard.. prolly 500lbs less load easy

160 MR-1 155mm pumps and Solas 12/18's bimini up, coolers and all the normal operational stuff in the boat and a little over 1/2 tank of fuel ~35 gal, 2 on board
it drops off bad if i push it past 9000 however its a ROCKET out of the hole literally just roll the throttles in, roll the desired RPM and wait a few seconds.... if i want it quicker I just run the trim tab down before throttling up and it holds a flat attitude and I just bleed off trim tab as it comes up to speed....

RPM GPS Speed (MPH)
1800 4.5
4000 15 and no tab... this is used for big wind and 3ft or better seas to keep the bow up and spray down
5000 25 using trim tab to get up on plane
6000 30
7000 35
8000 40
9000 45-47 (49 is the best ive seen with just me and no coolers n such on the boat)
10200 40

I think my wishing for 60MPH is not in the cards but ill get back to the low to mid 50's with better impellers and adjusting out the 5 or so degrees of static down trim for the two strokes... that was enough to get rid of the porposing, this is not needed anymore as I pushed the CG forward slightly due to the increased fuel capacity and moving the fuel tank forward to the ski locker... while i likely gave up some top speed doing this i'll take the improved ride all day long... Im happy better ride at cruise, better fuel economy (and range), quiet smooth and not stinky engines, not giving up any shallow water capability, no fuss no muss stating, and better alternator output. in all reality the 6000-8000 range is perfect and YDS says I spend most of my time at idle and 7000 RPM...

 

[Speedling]

waiting for the sunshine today... I'll have 25 hours on the repower at the end of the month... be time to change the oil and filters, and put my hotter plugs in... these motors seem to run a tad on the rich side compared to my seadoo 4 Tec as the seadoo is doggy lean and wont idle below 1800

the 32 at 5000 RPM i saw early on was 5 gal of fuel no bimini and none of the normal stuff in the boat and just me aboard.. prolly 500lbs less load easy

160 MR-1 155mm pumps and Solas 12/18's bimini up, coolers and all the normal operational stuff in the boat and a little over 1/2 tank of fuel ~35 gal, 2 on board
it drops off bad if i push it past 9000 however its a ROCKET out of the hole literally just roll the throttles in, roll the desired RPM and wait a few seconds.... if i want it quicker I just run the trim tab down before throttling up and it holds a flat attitude and I just bleed off trim tab as it comes up to speed....

RPM GPS Speed (MPH)
1800 4.5
4000 15 and no tab... this is used for big wind and 3ft or better seas to keep the bow up and spray down
5000 25 using trim tab to get up on plane
6000 30
7000 35
8000 40
9000 45-47 (49 is the best ive seen with just me and no coolers n such on the boat)
10200 40

I think my wishing for 60MPH is not in the cards but ill get back to the low to mid 50's with better impellers and adjusting out the 5 or so degrees of static down trim for the two strokes... that was enough to get rid of the porposing, this is not needed anymore as I pushed the CG forward slightly due to the increased fuel capacity and moving the fuel tank forward to the ski locker... while i likely gave up some top speed doing this i'll take the improved ride all day long... Im happy better ride at cruise, better fuel economy (and range), quiet smooth and not stinky engines, not giving up any shallow water capability, no fuss no muss stating, and better alternator output. in all reality the 6000-8000 range is perfect and YDS says I spend most of my time at idle and 7000 RPM...

Are you losing speed at full throttle?
With the less deep hull and that power you certainly should be at 60+mph.
Also, since i am catching up, i use the irridiums and change every other year. They appear perfect every time.
Is this the ho motors? Pretty sure they were. If i was hitting 52 unloaded pre-tower you definitely should be above that.
It all in the impeller. On my exciter i messed with impeller bending to get it dialed and i hit 65 mph gps. But that was before i had 3 kids to tend to.
Smooth that pump out, pull the air filters, drop in velocity stacks, cut the weight and let her rip. Either way i am glad i logged in and read this. This is awesome!
Now will that marine ecoboost fit in my old exciter?

 

[84rzv500r]

yep it starts cavitating around 9000 and starts slowing down...

 

[the MfM]

Nice work!!

I think if you can get back into the low 50’s you’ll be looking pretty good.

Playing with some numbers (guessing at some variables) and crouch’s formula shows with the slight increase in HP and increased weight you won’t be as fast as the two strokes.

I assumed a conservative 300 pound increase in weight and 280 hp for the mr1’s vs the 270hp two strokes…I could be way off but the numbers line up roughly with what you are reporting.

it’s been said the 140hp rating for the mr1 is conservative so you might do a little better.

 

[the MfM]

Are you losing speed at full throttle?
With the less deep hull and that power you certainly should be at 60+mph.
Also, since i am catching up, i use the irridiums and change every other year. They appear perfect every time.
Is this the ho motors? Pretty sure they were. If i was hitting 52 unloaded pre-tower you definitely should be above that.
It all in the impeller. On my exciter i messed with impeller bending to get it dialed and i hit 65 mph gps. But that was before i had 3 kids to tend to.
Smooth that pump out, pull the air filters, drop in velocity stacks, cut the weight and let her rip. Either way i am glad i logged in and read this. This is awesome!
Now will that marine ecoboost fit in my old exciter?

Only way an lst1200 is going to hit 60 is with 400 hp and keeping it light… maybe 3 two strokes?!?

 

[Speedling]

Only way an lst1200 is going to hit 60 is with 400 hp and keeping it light… maybe 3 two strokes?!?

View attachment 182875

I wonder what's top speed people get with the 2 strokes normally? Adding the little bit of power may be getting negated by the weight?
Exciter certainly different animal altogether. Mine had performance cranks and milled heads when i rebuilt. Hit 65 once but as soon as i had others it would stick at 60.

 

[84rzv500r]

fresh 2 strokes would hit 54-56 mph with a light load.... Solas 12/18's and 5 degrees down trim tab

I have 160 HP MR-1's
went to LiFePO4 batteries 260 lbs lighter but moved CG forward
weight is the same with the same fuel load...

engines and fuel load move the center of gravity forward about 16" keeping more hull in the water hence more wetted drag


Thinking about all aluminum hull and a pair of supercharged LS motors and Hamilton jet drives or a Cessna O-2/336/337

 

[84rzv500r]

ok so I lost a bearing in the starboard pump. so time to start upgrading the pumps I started rooting through parts pile getting ready to update the 155mm pumps and 20mm shafts with 12/18 impellers to 155mm pumps w/22mm shafts and 11/20 OEM impellers... well everything looks cool... I did learn that the 135's used low pressure pumps that is hub/pump inner diameter is ~20mm smaller than the FX HO Cruiser 155mm pumps... so I will keep the same pump base plate, and the same solas solid stainless impeller housings and switch to the FX HO stators, 22mm shafts, impeller's and tail cones. I'll have to tap and plug the output from the cooling water screen box on the fx ho stator housing and put a new fitting prolly in the cap and run a new line for the water intake... This should pick my speed back up and let me use all of the motors... and the exhausts really have a deep growl/howl through the 4" 135 waterboxes and through hulls...

PS dont worry about the chunks out of the stator housing this one was replaced long ago and i through it in the scrap pile just incase I needed any parts or the shaft for spares... and the bearings/seals in the housing are all the same in both setups...