# Bolens Lawn Tractor Model 1668 , Year 1990.



## bowjam

Bolens Model 1668 ,Year 1990. Mower in great shape. Only problem is the intermittent B&S engine.

BRIGGS & STRATTON L-head twin cylinders 16 HP model 402400:
I have to prime carburetor with gasoline to start and continue to prime till engine is running on it's on fuel. Engine can lose prime over night.Does this engine have a fuel pump ?
Also once engine gets hot (operating temperature) if it dies it will not start again until it cooled for several hours. Spark is very weak till engine has cool.
Engine runs strong and smooth as long as it doesn't die and need to be re-started. Suspect maybe the coil but it runs great till it dies ?
Any advice or suggestion will be appreciated.


----------



## SnowmanPA

*Sounds like a coil*

I am not familiar with this engine, but the older Onans and Kohlers had a regular automotive style coil. These would behave this way when they got hot.


----------



## MrGearHead

*Be careful!*

My Dad has the same motor. The charging system is intermittent on his machine and that caused the PTO clutch to disengage once in a while. (the clutch is electric so it takes electricity to make it work. THE BATTERY WOULD GO DEAD) He took it into the shop and they replaced the PTO clutch at a cost of $700!!!!! It was the charging system! NOT the clutch. Here's my point... My Mechanic neighbor and I had to rebuild the engine because Dad spent so much on the clutch. These motors only last 20 years. My Dad took VERY good care of his Bolens. It's in prime shape. However, one day out of the blue, it let loose. filling the carb and front yard with oil. My neighbor has rebuilt 5 of these engines in the last year. (the 20 year curse)


----------



## MrGearHead

Here are some photos of the mower / snow blower after rebuild...
2 pistons, rings, Valve seals, seats, guides + seal kit = $300. and a bunch of time. 
Hayppy to have it running again.


----------



## lsmurphy

$700 for a pto clutch?????????????????????????????????? Dad got screwed.

Can you post pics other than download?

Scott


----------



## SnowmanPA

*That's a bargain for a rebuild*

You are lucky that the engine is a Briggs & Stratton. I can't speak for the Kohlers, but the Onans in the older Bolens (mine is a 1973 QT-16 --Bolens 1666) cost over a grand to rebuild, just counting parts and machine work. I priced it out and figured that it was cheaper to repower my Bolens with a new motor.

I found a brand new 24hp Honda GX-670 on eBay for about $900...still in the original shipping box. I slipped that in there in the last month or so. I used my original 1973 clutch for about a 1/2 a lap around the yard and it fried. I found another one on eBay and I'm waiting for a break from work so I can get it back together. My grass is getting long!

I am working on a web album to document the whole repower process. I have a few pics in there now, but I have many more to post. 

Here is the link to that album:

http://picasaweb.google.com/tedrmiller/BolensQT16HONDARepower?feat=directlink

Hope you like it!


----------



## dangeroustoys56

All twins have fuel pumps - theyre fuel hungry engines- most are directly mounted on the carb, my 86 GTII with a 18HP opposed twin has large remote pump on the 'firewall' .

Id say the coil is probably going bad- its fine when its cool- but once it heats up it expands and causes a short .

About a PTO clutch- i looked up a new one for my GTII ( for the heck of it, i actually have a spare parts GT6000 with one) - from sears its like $400 - to test mine i just ran a positive and negative from a 12 volt battery to the connector plug on the clutch and it locked on- released the leads and it released - since my GT was serious messed up wiring wise , i just ran all new wires to a switch on the dash and hooked it directly to the battery ( i wired in a fuse as well)- havent had any issues with it. A weak battery or connection would make the clutch disengage.


----------

