did I blow the motor?

Yamaha Raptor 350 & Warrior Forum

Help Support Yamaha Raptor 350 & Warrior Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

roc805807

Member
Joined
Sep 28, 2009
Messages
6
Reaction score
0
I just got my warrior put together last night. the motor was rebuilt by the prev. owner and it was stripped down to the frame got it all put together and was riding and it just died out like it ran out of gas. sounds likes i lost some compression when i turn it over now. also it was sputtering at top end of all gears, which i believe is some tuning to do with the carb. kinda new to this. any help would be great. thanks.
 
How does it "sound like it lost compression" Have you since doen a compression test? Sputtering would and can be a carb problem. We need some more info to help yah out. How does it idle, Andy un-usual engine noise. It the timing in check? Ect.
 
I haven't done a compression test. It just doesnt sound like it was before, when you try to start it. It was running great, ran it down the road and it seemed like it ran out of gas and slowly stalled out. Tried to start it back up, no luck. Had to tow it home, checked for spark and fuel. No unusual noise, pulled the carb off, intake valve is still attached and moving. The motor was bored out by prev. owner so not sure if I will be able to do the carb myself. Not sure how complicated it is, plus can't remember what it was bored over to. Im not sure how to check the timing, but it was idleing fine. Also thought maybe I blew the head gasket. Any help is great. Thanks.
 
SO i take that it dosen't run at all at the moment. Correct? You have spark? Sounds to me like a typical stock crappy carb problem. (you have a stock carb, correct?) When it felt like it was runnin gout of gas, did you make sure that the gas we on? (you'd be surprised) Have you check that you petcock is clean and free flowing? Ned think I would do is get that carb off there, read the carb cleaning 101 post and also take note of the jetting. Also check to see that your carb to head boot isn't torn/ripped.
 
i was just going say say what deadlast said, check the boot between the carb and the engine. when i rebuilt my engine last winter, the very first ride i went on, it just slowly coasted to a stop and it wouldnt even begin to try to start. it freaked me out because it was only running for 5 minutes. come to find out that boot ripped and i put a new one on and she fired right up.

also if you do not think it has compression at all, take the spark plug out and put your thumb over the hole and turn it over. you should not be able to keep any compression from coming out of the spark plug hole. that will tell you if you have any compression at all, but it wont tell you how much you have.
 
No its not running at all currently. It is the stock carb, I know it needs to tuned a cleaned because it was bored over and probably never rejetted. Not sure if I am inclined enough to do it, I dont want to make it worse! It has spark. Kinda funny about a half hour before that, it did run out of gas, the gas was off. Took the petcock apart and cleaned it, it is free flowing. I don't have a rubber boot on the block it is aluminum, guessing thats after market? Also can I do that compression test with the carb off? I don't really see why not, but thats why Im on here, pretty new to this stuff. Thanks guys.
 
roc805807 said:
No its not running at all currently. It is the stock carb, I know it needs to tuned a cleaned because it was bored over and probably never rejetted. Not sure if I am inclined enough to do it, I dont want to make it worse! It has spark. Kinda funny about a half hour before that, it did run out of gas, the gas was off. Took the petcock apart and cleaned it, it is free flowing. I don't have a rubber boot on the block it is aluminum, guessing thats after market? Also can I do that compression test with the carb off? I don't really see why not, but thats why Im on here, pretty new to this stuff. Thanks guys.

if your carb is a round slide type then it sounds like for sure it is aftermarket because no warrior came with this type of manifold or carb.
Yup when you do a compression test you should have the throttle wide open. So that would work great with the carb off.
I have heard that some times when people rebuild there engines they forget to put thread locker on the cam bolt. It backs out and the piston takes out a valve. Might just want to pull the cam cover if you think that might have happen.
Sounds like it is jetted a little rich with the top end miss.
Good luck and any more info would be great.
 
Yea Im not exactly sure about the manifold but I'm pretty sure it is a stock carb. Pulled the motor it had no compression. I could hold my finger on it no problem, nothing coming out. Drained the oil and found a nice little chunk of metal in it a little smaller than a dime. So something is pretty screwed. I had a spare motor that I bought never heard it run though, its a older one from 87 or 88 cause it has the pull start and its a six speed which I just found out today. I put that in there, turns over nice sounds pretty good with no clunks. Didn't get it started though. Wiring is a little different than my harness, plus I forgot to put a wire on that, which is probably why I had no spark. We'll see what happens. Its probably going to be a hair puller! ha, thanks.
 
roc805807 said:
Yea Im not exactly sure about the manifold but I'm pretty sure it is a stock carb. Pulled the motor it had no compression. I could hold my finger on it no problem, nothing coming out. Drained the oil and found a nice little chunk of metal in it a little smaller than a dime. So something is pretty screwed. I had a spare motor that I bought never heard it run though, its a older one from 87 or 88 cause it has the pull start and its a six speed which I just found out today. I put that in there, turns over nice sounds pretty good with no clunks. Didn't get it started though. Wiring is a little different than my harness, plus I forgot to put a wire on that, which is probably why I had no spark. We'll see what happens. Its
probably going to be a hair puller! ha, thanks.

ah damn.. I wonder if the valve made friends with the piston. That sucks man, wish you the best with the other engine. When you have the modded one out you should take it appart and see what happen. EDIT: maybe can learn from it and get better at taking stuff appart and working on engines.. not have to worry about breaking anything on it. ;D
 
Yea I want to but I my first thing is getting that other one goin. Yea Id like to put some more mods on the blown one since it is going to have to be taken apart, but it probably goin to the shop so well see.
 
you can put the stator out of your screwed up engine in the older one and the wireing harness will match :)
 
Also, just for the record an overbore is not going to increase your cc's by any notable amount. Certainly not any amount to require a carb rejet.

Invest in a compression tester. They are inexpensive but when it comes to diagnosing an engine they are worth their weight in gold. I compression test everything before I buy it these days. Sleds, quads, done a couple cars, etc.

What did the piece that came out of the newer motor look like? I almost want to say the previous owner broke either a ring or a ring land when they were installing their new piston/ring.
 
Yea it didnt really look like a ring it was a pretty thick chunk of metal, not to sure what it was. I really just want to get the other one goin. So I swapped out the stator out of another motor that I had, got it all back together and still no spark? Don't know whats goin on, guess that stator could be bad? Any help would be great thanks.
 
Back
Top