3 hours on new top end

[glenwhitt]

Howdy all. I have 23 hours on complete motor including new Hotrods crank. I experienced a massive loss in compression in the mag cyl. I took off the head and noticed rust and scoring in the pto side and massive scoring with no rust in the mag. took it to the boat mechanic. took top end off. mag piston was working the the sleeves and the rings were froze around the piston. Also new R&D head had pits on the mag dome also (go figure). Replaced top end with new jugs, pistons, rings, pins, oem head, gaskets, etc... before I started this back up

I replaced both carbs with new mikuni 40mm sbni and jetted mag to 147.5 and pto to 150 on the highs. Left everything else stock and 1.25 turns out on the low speed. Started out with 1 turn out on the mag and ok color and 2 turns out on the pto but still some brown (I now have 152.5 coming and will replace the 150 with it and then use the 150 in the mag thinking this will be good with the prok arrestors I have on.

First two hours on lake were fun but hard starting when in water and warm. Had to hold throttle wot when starting until it started to chug then would drop back to .25 and it would smooth out. Had some hesitation at half throttle but ¾ to wot was nice. Though I would adjust carbs more next time out.

Next time was today and after just an hour the boat started running strange and missing at different rpms. I took it slow back to the trailer and brought it home. I know have a 5 psi lower change on compression in the pto side and 10 psi lower compression change on the mag side.

What do you think of the following pics here.

 

[glenwhitt]

3 hours on new top end #2

rest of the pics

 

[timmyboy76]

carbon rv

from what i've read, DONT run that thing. Will post later, if need assurance, about those carbon rv's.
With install'n proks, did you lower the n/s pop-off, inside da carbies?
For what its worth, and I aint say'n to NOT mod it, but it is a boat, that ways, way more than jetski, and with weight difference, its gonna perform touchy, even to extent of cost'n you nuther motor, til you have it dialed in right.
You can throw, stock box back on, install the stock RV, set it to right time, and set carbs to factory setting, and rip the boat that way. The boat, stock does fifty..? again, not knock'n the mod thing, just, can see it being a headache until right...:cheers:

 

[glenwhitt]

Not sure what damange i have done so far. The cyl walls look ok and all the piston is there. No damage to the head either. Spoke to someone and told them the pto cyl was lower compression as the other. he asked if that was the problem last time. i said no. he asked if the pto side was the side with rust in it before. i said yes. he asked if there was water in it when i pulled off the head this time. i said yes but thought it just spilled out from removing the head, even though i was pretty careful. Also told him water was still to the top in the jug around the sleeve on the pto side. Said first off it is not draining correctly so the water may have come from there. I cleaned out the cylinder and tride to pump anything from out of the crank case. nothing came out of the crank case though. This person also told me that if water was in the cyl than that could be washing it and causing the low compression. Said things are savable if there is no rust. Looks like i will be pulling off that jug at least and seeing what is blocking it. When i put back together I will leak test it. i also have a block off kit coming and will use premix to insure proper oiling. will also rejet the carbs again t get more plug color.


Any other suggestions??????

Only one i am thinking of is the rosier engine for $1,300.00 with my block and i do all the labor

http://www.rossiereng.com/products.php?product=1191609645

 

[glenwhitt]

rv

I have new seadoo rv and rv cover oring on the way also. I still have factory box and the factory jets an will consider this when putting back together. If I do this i will 100% modless

 

[glenwhitt]

pop off psi

BTW I did not change anything nor test the pop off from the oem carbs. Is this important for engine damage or just running well through the power band?

 

[timmyboy76]

Factory Pipe, carb tuning...

BTW I did not change anything nor test the pop off from the oem carbs. Is this important for engine damage or just running well through the power band?

When does it become necessary to adjust pop-off?
When personal watercraft come from the factory they have fairly high pop-off due to the fact that they also have somewhat restrictive air intake systems that cause the engine to generate very high manifold pressures; the higher the manifold pressures, the higher the pop-off pressure required to properly regulate the fuel delivery to the engine. As you modify or change your watercraft's flame arrestor to a less restrictive type you will most likely start to experience a lean hesitation caused by a decrease in manifold pressure. This change will require an adjustment in pop-off pressure to regain crisp throttle response. Because most aftermarket flame arrestors are less restrictive than stock, you will need to decrease pop-off to compensate

 

[glenwhitt]

pop off

What should pop off psi be? Where is the best place to get a pop off gauge? What color spring will get me to the correct pressure? Should I change jet and/or needle also?

I do not have a factory pip on it yet. I was thinking about it though. I still have oem purple pipe on it, and now the oem head. I have the oem rv coming this week to replace the aftermarket carbon fiber one with a different degree other than factory. I will test my clearance also on the rv and cover with a feeler gauge.

Also going with block off kit for now. Will spend time later testing the injector pump before putting back on or maybe even buying a new one.

What about the pistons and the color in the pics? What would you say about each as far as lean/rich? Color telling you anything here?

Thanks for your help timmyboy. Sorry for all the questions. I would like to put this together soon and get back on the lake for the year

 

[timmyboy76]

starting point..

IF, you ran the aftermarket set-up....proks, head..etc, then should start out with, 2.0n/s and black spring, which puts around 21psi.
If, going back to stock-setup, then, and if you didnt change anything in the carbs...n/s, spring..etc, then you should be ok, leave whats in there, install stock head, stock air system, and stock RV plate, which is the 159* wheel. Do not go with any size smaller, you'll just be, chasing ur tail, again...

 

[glenwhitt]

starting point

Good stuff. I think i will go back to all stock and go out for the summer. I will get the pop off gauge though and insure it is matching factory specs before putting back together.

Think the pistons are ok in this? does the color on these tell you anything? I just hate to put it all together and have it grenade. I can get a complete top end ready to bolt on from SBT for $475.00

http://www.sbtontheweb.com/Merchant...ode=62-107&Category_Code=62-1&Product_Count=5

comments???? Thanks!

 

[timmyboy76]

watch the compression now. They're only a 5psi difference, so, i think there good.
You can, as long as no big gouges in sleeves, take to machine shop, have them "honed" for 10buks a barrell, then contact this guy, for whatever size your barrells "myce" out to...std, .25, .50, .75, 1mm

http://cgi.ebay.com/ebaymotors/SEAD...10374333172QQptZPersonalQ5fWatercraftQ5fParts

 

[glenwhitt]

Cost a lot less. I think mine are just about maxed anyway though. They were done 23 hours ago and then another 3 ago (ride time). I will have to inspect them further and see if I would need new sleeves or not I guess.

Thanks for all the input and advice. Major help.

 

[timmyboy76]

yeah, if they need sleeved, then that looks like your best bet..(sbt). A decent place, will run AT-LEAST, 200 buks for both, i paid 350 for mine to get sleeved..(didnt know about this site/sbt)..:banghead:

 

[glenwhitt]

back to stock

Done a lot of work tonight, and drank a few beers

Factory jetting is 142.5 on mag and 147.5 on pto. I rejeted carbs to this. I also checked pop off at 23 psi per carb with black spring. Needle holds fine in seat also with 10 psi. Checked fuel pump diaphragm also.

Squish on head was good so I cleaned and used new gaskets and bolted head back on. With carbs off now I have 149 psi in both cyl (last time I checked before tear down I forgot to open the carbs up for air).

Put 159 degree oem rv back in and timed. Right on the mark at 146.5 (+/- 2.5 with play). Bolted rv cover on also with new oring.

Removed oil injector pump and installed block off kit (put caps on rv cover and zip tied before bolting rv cover down also).

I have pipe cleaned and ready to bolt back on with new gaskets and carbs ready to bolt back on with new gaskets (will synch them to the tee also). Then its to the gas station tomorrow to premix some fuel and start this mother. Sunday I plan on lake testing ( and drinking more beers). Will start at 1.25 turns out on low and .5 turn out on the high. I think this over but better rich than lean on the get go so I can adjust. Oh ya... Will have factory air box on this also.

Bottom line, after several thousand dollars in new motor, and then a new top end, and all the mods, I am back to oem and I have a funny feeling this will be the best it has ever ran

I will update tomorrow or Sunday after the lake test.

 

[CypherAZ]

we are heading out to pleasant on sunday.

 

[glenwhitt]

making progress

Pleasant is not on the radar this weekend. I can be from my door to canyon in 60 minutes. It is over two hour s to Pleasant for me. Roosevelt is a faster trip than Pleasant now they have all the roads done up by Globe way. I think that is about 1.5 hours. I am kinda loyal to Canyon, it is a nice lake. atriot:

Think I know why water lines are nor draining from bottom of cylinders. It seems the blockage is the fitting all the way on the back at the exhaust pipe. I try to blow through this and nothing. Should it be that way? Will pull that this morning and unclog. (see pic part I put green circle and red arrows on) Will test all the other water lines and fittings also.

Question: is it ok to bypass the fuel selector switch and bypass the lines so it just runs off the res side all the time? I never use this thing and always stay’s on res. Last year when I cleaned the tank and replaced all the lines I was never able to get the lines replaced that run back and forth to the selector as I was unable to get the selector out. I sure hate for something in that system to be a cause for problems. The stock fuel filter is clean as well as the carb filters as I just checked them yesterday. They had no particles in the at all.

Will start working later this morning on it and should have it running early afternoon.:cheers:

 

[timmyboy76]

not good, need to clear that out...and for bypass'n the switch...yep, doin it to the challenger i got. Like you said, use the "res" line to filter, then filter to carb..walahh

 

[glenwhitt]

water lines

This could be what caused the prior top end (23 hours old) to go bad then. With the water not flowing through like this I am sure there were some heat issues. I just read a post were doc stated "if you rebuild/replace a motor without finding the cause from the prior failure...."

Glad I am taking my time and testing everything. Thanks for the info on the selector bypass. will do that today also. Did you just cap the ON nipple since it is not being used anymore? So RES to filter IN, Filter OUT to CARB, put a cap on the ON nipple? Thanks Timmyboy

 

[glenwhitt]

water fitting clean now

I got the fitting out and cleaned it. I used a little pick and small drill bit to get all the sand out of it. is was full of sand and 100% cloged. The pic shows the stuf that came out of this on a red shop rag. Took pic with phone so not best quality. Will bypass fuel selector switch this morning and head to the lake.

Got it all assembled and started it up last night.

 

[glenwhitt]

running pretty good now

Took the boat to the lake yesterday and she did pretty well. Since cleaning the fitting to allow the water to drain out of the top end I notice my exhaust is hotter. This thing use to be ice cold all the time in the water.

Max rpm is 6850 on the tiny tac. I will take apart and reassemble the rave valves. They are spitting oil pretty good. This could be keeping my rpm down a bit. I notice in the parts book there is a spring for the bottom, like for the top. I do not have those bottom springs and am using zip ties. I think using the zip ties is leaving a little pucker allowing for exhaust gasses/oil to push through.

Still very hard starting. If I run it shut it off and immediately start it again it will start right up. If I let it set a minute I have to hold wot and crank the starter till she fires. Then it slowly jugs along, rpm’s pick up, and comes back to life. I also think I should have used the silver pop off springs with the oem air box. She is coming off low speed circuit to fast. When it makes the switch I have to open up the throttle to let air in or she bogs.

Thanks for the help guys. Looks like I have a boat for the summer now :hurray:

 

[timmyboy76]

rite-on, glenn

If, you can get a "stock" n/s spring, that be ur best bet...did you clean the carbs, and take a look at the eccelerator fitting, make'n sure its "squirting" gas, dow carb. You can see it, with flame arrestor off..:cheers:

 

[glenwhitt]

new carbs

Both carbs are brand new, not rebuilds (well now they have 6 hours on them). I got them from Parker a few weeks back. I still have the stock spring that came with them. Those were giving me a 30-31 pop off. The black springs that APS said I should use are only giving me 21-22 pop off. I verified i have 70's for the low's and 142.5 high in the mag side with 147.5 high in the pto side. Only thing not stock spec is the pop off springs. I did not check needle size but they should be 1.5 and i will do so when replacing the springs

When you said "look at the eccelerator fitting, make'n sure its "squirting" gas, dow carb. You can see it, with flame arrestor off" are you talking about the pump on the pto carb? Should it be? Do I check this running?

Thanks

 

[timmyboy76]

they set those carbs up, on "description" of what you were running, right..?

as for eccelerator, yeah, pull the arrestors off, and throw throttle forward, you'll see it squirt'n fro mthe fitting, BUT..being brand new carbs, think its ok..

 

[glenwhitt]

new carbs

No one has touched the carbs but me. These are the oem carbs and so far they have had everything in them that the book calls for. I guess i should have left it alone and I would not have to take them off again for a spring change. When I talked to APS and told them what I was doing he recomened the black springs. After I get the silver ones on it I will pop off test and put them back on (hopefully last time for year). Thanks!

 

[timmyboy76]

those springs are "CRUCIAL", for carb/motor run'n correctly...:cheers: