Thread: 800's noisy engines... BEWARE!!!
09-05-2007, 08:40 AM #1
800's noisy engines... BEWARE!!!
I received all the parts for my 2002 XLT800 (WAVEEATER CLIPS, COUPLING,OIL LINE CLIPS, GASKETS, ETC) and start working on it this past Holiday weekend. Everything went fine 'till I checked the pistons. The rear one, which was the one that runs dry looks just like that (dry),but normal, the front piston has some scratches, but in only two sides as well as the piston. The PV on that side looks normal (pics attached).
I haven't remove the cylinder head yet.
I noticed some oil in the manifold on that side only
This darn engine still have 125psi on both cylinders and runs great( but it leaks the press on the gauge) (I have to double check the gauges on my other ski engine)
I maybe wrong, but I believe that's is where that knocking is coming from, but...
1- why in two sides only and not the entire cylinder and piston are scratched?
2- why if the rear cylinder was the one that lost lube when the line fell off is normal and the front one is scratched?
3- can I just send to a machine shop or replace that OEM cylinder, install new rings on both pistons and get away with the scratches on that piston?
I hate to do this but I really don't have the time right now to convert this in a big project; (remove the engine, crankshaft, etc)
See pics attached
09-05-2007, 09:32 AM #2
You need to pull the head to get a better idea of the damage to the cylinders. Hard to tell from the pictures but it does appear to have seized.
09-05-2007, 09:34 AM #3
Welcome Mr WR.
As Bill said, pull the cylinders, heads and pistons. You got a little work ahead of you. Show us what the parts look like and let's see what we can figure out!
09-05-2007, 11:10 AM #4
- Join Date
- Jan 2006
Whilst it does look like the eng has siezed at some point, this may not be the source of the knocking.
I had a 800 and that used to knock quite badly at tick over, but fine once you raised the revs. ie 1500 it sounded like a bag of nails and like the big ends had gone . At 2500 and above it was OK and smooth. Well a smooth as a two 2 stroke can be.
The cause of this was that the carbs were out of balance.
In this case they needed to be pulled off and balanced using feeler guages, so that both butterflys open together and with the same gap at idle (the cause of the knocking).
Answer to your other questions is going to be based on how bad the sieze and alloy deposits are. At best a clean up and new rings
09-05-2007, 11:45 AM #5
The scratched cylinder is not that bad
The piston has deep scratches
The rings on both sides looks normal
The rod bearing on the scratched side has a little more play than the other one.
Rear piston,cylinder and the heads looks normal
I don't know jack s**t about these 2 cycle engines, but I think I am going to hone that cylinder a little bit, install new rings on both sides and a new OEM piston in the front. I may just get away leaving that piston there - ? I should replace that rod bearing, but don't think I am pulling the engine off to work on that. I just don't have the time and I am not paying anybody to rip me off.
Any sugestions will be greaty appreciated
SEE THE PICS
09-05-2007, 11:48 AM #6
09-05-2007, 11:58 AM #7
A few things for you.
These cylinder types can not be "Just Honed." These are what is called Nikosil coated cylinders. That shiny surface is the coating. Underneath it is bare aluminum. If you hone it, then you will hone into the aluminum. It will run...for about 30 minutes or less.
What you can try and do, is use muratic acid to remove the aluminum piston material from the nikisil. IF all the aluminum comes off, and you do not have scratches or cracks in the nikisil (highly unlikely) then you can re-use the cylinder... with mixed results.
Your best bet is to get a refurb cylinder/piston from places like millenium technologies. They can swap out the 66E cylinder that you have (assuming they have any in stock.)
Now that crank has me worried. It looks like a rebuild, and if those black marks are related, it could have lost a bearing. Do you have any play in the rods? Does the crank make any clicking or grabbing sounds when you gently spin it by hand?
09-05-2007, 12:15 PM #8
I greatly appreciated you quick response. When I spin the crankshaft it doesn't make any sound. The bearings act normal, but I have a little more play on the scratched side rod bearing than the other one
The engine sounds like kevski described and have a lot of power
Compresion is still @ 125-130 on both sides
If I have good results cleaning the cylinder with the acid, can I still use that piston with a set of new rings on both sides?
What do you recommend?
09-05-2007, 12:27 PM #9
i know alot of people on here dont like SBT in florida but last april i sent them a bad cylinder and a good one and they sent me back 2 good ones with pistons for 422$ stock size and if i recall correctly they are slightly boreable??? since they were the replated ones. but i dont have my paperwork in front of me.... but it looks like you def need to replace the 1... if i could do it all over again i would do a 926 BB engine. but last year before i found greenhulk i had no idea about any of this. now thanks to this damn site im making a conversion ski and BB gpr Damn you greenhulk!
09-05-2007, 12:29 PM #10
I'd have my pecker dipped in muratic acid before I'd use their parts...but that's just me.
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By hunting080189 in forum Yamaha PWC Performance (2-stroke)Replies: 5Last Post: 10-24-2009, 12:50 PM
By 240witSR in forum Sea Doo ClassifiedsReplies: 5Last Post: 05-18-2008, 01:49 PM
By zrtman in forum Conversion Skis ClassifiedsReplies: 1Last Post: 02-28-2008, 11:15 AM
By joaqslam in forum Yamaha Open DiscussionReplies: 7Last Post: 02-04-2008, 12:49 PM
By jetskiguy69 in forum Yamaha PWC Performance (2-stroke)Replies: 2Last Post: 12-08-2007, 10:44 PM